260. Blake, AJ; Hung, EMN; To, S; Ng, G; Qian, JM; Gries, G. (2023) Stable flies sense and behaviorally respond to the polarization of light.J. Comp. Physiol. A -Neuroethol. Sens. Neural Behav. Physiol.Stable flies sense and behaviorally respond to the polarization of light
Stomoxys calcitrans; Muscidae; Insect vision; Polarization vision; Photoreceptors
Insects use their polarization-sensitive photoreceptors in a variety of ecological contexts including host-foraging. Here, we investigated the effect of polarized light on host foraging by the blood-feeding stable fly, Stomoxys calcitrans, a pest of livestock. Electroretinogram recordings with chromatic adaptation demonstrated that the spectral sensitivity of stable flies resembles that of other calyptrate flies. Histological studies of the flies' compound eye revealed differences in microvillar arrangement of ommatidial types, assumed to be pale and yellow, with the yellow R7 and pale R8 photoreceptors having the greatest polarization sensitivity. In behavioural experiments, stable flies preferred to alight on horizontally polarized stimuli with a high degree of linear polarization. This preferential response disappeared when either ultraviolet (UV) or human-visible wavelengths were omitted from light stimuli. Removing specific wavelength bands further revealed that the combination of UV (330-400 nm) and blue (400-525 nm) wavelength bands was sufficient to enable polarized light discrimination by flies. These findings enhance our understanding of polarization vision and foraging behavior among hematophagous insects and should inform future trap designs. DOI PubMed
259. Lemke, E; van Herk, WG; Singleton, K; Saguez, J; Fowler, G; Pepper, D; Furtado, K; Gries, G. (2023) Mixed sex pheromone lures for combined captures of Agriotes and Limonius pest click beetles in North America.J. Appl. Entomol. 147: 592-601 Mixed sex pheromone lures for combined captures of <i>Agriotes </i>and <i>Limonius </i>pest click beetles in North America
Elateridae; insect chemical communication; integrated pest management; pheromone-based monitoring; species detection; wireworms
Sex pheromone lures are effective tools for monitoring and potentially controlling populations of pest click beetles (Coleoptera: Elateridae). To date, these lures are genus-specific (e.g., Limonius spp.) or species-specific (e.g., Agriotes lineatus Linnaeus). However, if sympatric heterogeners were not to be repelled by each other's pheromones, trap lures effective for multiple elaterid genera could be developed, improving cost efficiency in elaterid pest management programs. In both western and eastern North America, several species of Agriotes spp. and Limonius spp. co-occur and inflict similar crop damage. We investigated whether the sex pheromones of these species can be combined in a mixed lure without reducing its attractiveness to all target species. In western Canada, we show that the pheromones of A. lineatus (geranyl butanoate & geranyl octanoate) and Limonius spp. [(E)-4-ethyloct-4-enoic acid (limoniic acid)] can be combined without significantly reducing captures of male A. lineatus, L. canus (LeConte), L. californicus (Mannerheim) and L. infuscatus (Motschulsky) relative to traps baited with species-specific lures for A. lineatus and Limonius spp.. Similarly, the pheromone of A. obscurus (Linnaeus) (geranyl hexanoate & geranyl octanoate) and limoniic acid can be combined without significantly reducing trap captures of male L. canus, L. infuscatus and L. californicus but reduced A. obscurus captures relative to traps baited only with the A. obscurus pheromone. In eastern Canada, combining pheromones for Agriotes mancus (Say) (geranyl butanoate & geranyl hexanoate) and limoniic acid reduced captures of A. mancus but not A. pubescens (Melsheimer) and A. sputator (Linnaeus). These data imply that pheromones of select elaterid heterogeners can be combined in a 'catch-more' pheromone lure to effectively monitor for, or possibly control, multiple elaterid pests, but that such mixed lures should be evaluated for each species combination. DOI
258. Long, JS; Maskell, K; Gries, R; Nayani, S; Gooding, C; Gries, G. (2023) Synergistic attraction of Western black-legged ticks, Ixodes pacificus, to CO2 and odorant emissions from deer-associated microbes.R. Soc. Open Sci. 10 Synergistic attraction of Western black-legged ticks, <i>Ixodes pacificus</i>, to CO<sub>2</sub> and odorant emissions from deer-associated microbes
Ixodes scapularis; Ixodes pacificus; Odocoileus virginianus; sebaceous gland secretions; microbes; semiochemicals
Foraging ticks reportedly exploit diverse cues to locate their hosts. Here, we tested the hypothesis that host-seeking Western black-legged ticks, Ixodes pacificus, and black-legged ticks, I. scapularis, respond to microbes dwelling in sebaceous gland secretions of white-tailed deer, Odocoileus virginianus, the ticks' preferred host. Using sterile wet cotton swabs, microbes were collected from the pelage of a sedated deer near forehead, preorbital, tarsal, metatarsal and interdigital glands. Swabs were plated on agar, and isolated microbes were identified by 16S rRNA amplicon sequencing. Of 31 microbial isolates tested in still-air olfactometers, 10 microbes induced positive arrestment responses by ticks, whereas 10 others were deterrent. Of the 10 microbes prompting arrestment by ticks, four microbes-including Bacillus aryabhattai (isolates A4)-also attracted ticks in moving-air Y-tube olfactometers. All four of these microbes emitted carbon dioxide and ammonia as well as volatile blends with overlapping blend constituents. The headspace volatile extract (HVE) of B. aryabhattai (HVE-A4) synergistically enhanced the attraction of I. pacificus to CO2. A synthetic blend of HVE-A4 headspace volatiles in combination with CO2 synergistically attracted more ticks than CO2 alone. Future research should aim to develop a least complex host volatile blend that is attractive to diverse tick taxa. DOI PubMed
257. Nayani, SA; Meraj, S; Mohr, E; Gries, R; Kovacs, E; Devireddy, A; Gries, G. (2023)Staphylococcus microbes in the bovine skin microbiome attract blood-feeding stable flies.Front. Ecol. Evol. 11 <i>Staphylococcus</i> microbes in the bovine skin microbiome attract blood-feeding stable flies
microbe; Staphylococcus; Stomoxys calcitrans; attraction; semiochemical; ammonia
The human skin microbiome reportedly contributes to the attraction of mosquitoes to human hosts. We tested the hypothesis that bovine skin microbes affect the attraction of blood-feeding stable flies, Stomoxys calcitrans, to their bovine hosts. Microbes were collected from a calf and adult cow, and subsequently isolated and identified by mass spectrometry and genetic sequencing. Separate groups of (i) four Staphylococcus congeners (S. chromogenes, S. sciuri, S. simulans, S. succinus) and (ii) three bacterial heterogeners (Glutamicibacter protophormiae, Corynebacterium stationis, Wautersiella sp.) grown on agar, each attracted flies in still-air olfactometers, as did each Staphylococcus congener singly. The four Staphylococcus microbes also attracted flies in room bioassays. In greenhouse bioassays with paired black barrels as visual (surrogate host) stimuli, the treatment barrel baited with S. sciuri on agar induced significantly more fly alighting responses than the control barrel with sterile agar. This treatment effect could not be demonstrated on a cattle farm, possibly because of chemically and visually complex surroundings. Ammonia emitted by Staphylococcus microbes attracted flies, and a synthetic blend of microbe odorants enhanced the attractiveness of ammonia. Optimal attraction of stable flies to bovine microbes likely requires the integration of multimodal host cues. DOI
256. Singleton, K; van Herk, WG; Saguez, J; Scott, I; Gries, R; Gries, G. (2023) Sex pheromone of Nearctic Agriotes mancus and its similarity to that of three Palearctic Agriotes invasive in North America.Agric. For. Entomol. 25: 468-476 Sex pheromone of Nearctic <i>Agriotes mancus</i> and its similarity to that of three Palearctic <i>Agriotes</i> invasive in North America
Agriotes mancus; click beetles; Elateridae; geranyl esters; identification; lure; monitoring; sex pheromone; trapping
The wheat wireworm, Agriotes mancus (Coleoptera: Elateridae), is a predominant elaterid pest species in the Nearctic region, with a life history and morphology similar to those of Agriotes obscurus, Agriotes lineatus and Agriotes sputator, three Palearctic pest elaterids invasive in North America. Here, we report the identification and field testing of the sex pheromone of A. mancus.We collected headspace volatiles from female beetles on Porapak Q, and analysed aliquots of Porapak extract by gas chromatography with electroantennographic detection (GC-EAD) and by GC-mass spectrometry. In GC-EAD recordings, two esters-geranyl butanoate and geranyl hexanoate-elicited antennal responses from A. mancus males. In field experiments, trap lures containing both geranyl butanoate and geranyl hexanoate afforded large captures of A. mancus males, which were-on average-approximately 30-fold higher than captures in traps baited with a single ester.Traps baited with geranyl butanoate as a single-component lure captured a significant number of Palearctic A. sputator, indicating the establishment of A. sputator in its invaded Nearctic range.With the A. mancus sex pheromone now known, it can be included in the development of pheromone-based programmes to monitor and manage native and invasive Agriotes pests in North America. DOI
255. Varner, E; Mark, K; Jackson, H; Singleton, K; Luo, L; Johnson, S; Gries, R; Gries, G. (2023) Rodent odour bait: A new bumble bee conservation tool to enhance nest box occupancy.Insect. Conserv. Divers.Rodent odour bait: A new bumble bee conservation tool to enhance nest box occupancy
house mouse; nest site selection; olfaction; pollinator conservation; queen bumble bee; synthetic rodent odour
Bumble bee conservation focuses on supplementing floral resources. Yet, nesting site availability is linked to bumble bee abundance. As a supplement to natural nest sites, nest boxes could be deployed and baited with synthetic lures.As queen bumble bees reportedly establish colonies in abandoned rodent burrows, we hypothesized (1) that queen bumble bees sense, and behaviourally respond to, rodent odour, and (2) that lures of synthetic rodent odour can guide spring queens to nest boxes.We collected headspace odorants from bedding soiled with urine and faeces of house mice, Mus musculus, and identified the 10 odorants that elicited responses from queen antennae.To field-test attraction of queens to mouse excreta odorants, we tree-mounted paired nest boxes in florally rich locations, and assigned clean and soiled bedding, respectively, to one box in each pair.Queens established colonies in 17 mouse-scented boxes and in six unscented boxes. This 43% occupancy rate of mouse-scented boxes represents a significant improvement over the 10% occupancy rate common for unscented boxes. In a further field experiment, we baited one box in each pair with a synthetic mouse odour lure and found that queens established colonies in 13 baited boxes and in six unbaited control boxes. Specifically, Bombus mixtus established seven colonies in baited boxes and only one colony in an unbaited box.With this proof-of-concept that synthetic lures can guide queens to nest boxes, we anticipate that bumble bee conservation programs will soon be able to offer both expanded floral resources and baited nest boxes readily detectable by queens. DOI
254. Fischer, A; Gries, R; Alamsetti, SK; Hung, E; Torres, ACR; Fernando, Y; Meraj, S; Ren, WW; Britton, R; Gries, G. (2022) Origin, structure and functional transition of sex pheromone components in a false widow spider.Commun. Biol. 5 Origin, structure and functional transition of sex pheromone components in a false widow spider
Female web-building spiders disseminate pheromone from their webs that attracts mate-seeking males and deposit contact pheromone on their webs that induces courtship by males upon arrival. The source of contact and mate attractant pheromone components, and the potential ability of females to adjust their web's attractiveness, have remained elusive. Here, we report three new contact pheromone components produced by female false black widow spiders, Steatoda grossa: N-4-methylvaleroyl-O-butyroyl-L-serine, N-4-methylvaleroyl-O-isobutyroyl-L-serine and N-4-methylvaleroyl-O-hexanoyl-L-serine. The compounds originate from the posterior aggregate silk gland, induce courtship by males, and web pH-dependently hydrolyse at the carboxylic-ester bond, giving rise to three corresponding carboxylic acids that attract males. A carboxyl ester hydrolase (CEH) is present on webs and likely mediates the functional transition of contact sex pheromone components to the carboxylic acid mate attractant pheromone components. As CEH activity is pH-dependent, and female spiders can manipulate their silk's pH, they might also actively adjust their webs' attractiveness. New chemical components to female spider pheromones are identified in the false black widow spider, Steatoda grossa. DOI PubMed
253.Gries, R; Khaskin, G; Cepeda, P; Gries, G; Britton, R; Borden, JH. (2022) Attractive host kairomones for the cigarette beetle, Lasioderma serricorne (Coleoptera: Anobiidae).J. Stored Prod. Res. 99 Attractive host kairomones for the cigarette beetle,<i> Lasioderma</i><i> serricorne</i> (Coleoptera: Anobiidae)
Cigarette beetle; Lasioderma serricorne; host kairomones
Analyses of pooled headspace volatiles from three commercial chili pepper, Capsicum spp., products by coupled gas chromatographic-electroantennographic detection (GC-EAD) and coupled GC-mass spectrometry (MS) revealed 10 compounds (beta-pinene, gamma-terpinene, linalool, 2-phenylethanol, cumin aldehyde, 1,3-menthadienal, eugenol, trans-beta-caryophyllene, caryophyllene oxide, and an unknown compound which co-eluted with 2-phenyl -ethanol) that elicited responses from the antennae of cigarette beetles, Lasioderma serricorne. The unknown compound was separated by silica fractionation and identified by MS and NMR spectroscopy as 2-hydroxy-2,6,6-trimethyl-cyclohexanone. In Y-tube olfactometer bioassays, beetles were attracted to the 10-component synthetic blend and to many six-and four-component blends, demonstrating widespread redundancy in bioactivity among the components. Eugenol was discounted as an attractant, whereas beta-caryophyllene and linalool had previously been identified as kairomones for L. serricorne. The remaining seven compounds are novel host kairomones for L. serricorne , bringing the total of known host kairomones for this species to 18. The redundancy among host kairomones may enable L. serricorne to find and infest many highly variable stored products, any one of which may emit only a few of the known kairomones. DOI
252. Lemke, E; van Herk, WG; Singleton, K; Gries, G. (2022) Seasonal and Diel Communication Periods of Sympatric Pest Limonius Click Beetle Species (Coleoptera: Elateridae) in Western Canada.Environ. Entomol. 51: 980-988 Seasonal and Diel Communication Periods of Sympatric Pest Limonius Click Beetle Species (Coleoptera: Elateridae) in Western Canada
click beetle; wireworm; pheromone; reproductive isolation; monitoring
In western North America, sympatric Limonius click beetle species produce limoniic acid [(E)-4-ethyloct-4-enoic acid] as a sex pheromone component (L. canus (LeConte), L. californicus (Mannerheim)) or respond to it as a sex attractant (L. infuscatus (Motschulsky)). We tested the hypothesis that these three congeners maintain species-specificity of sexual communication through nonoverlapping seasonal occurrence and/or contrasting diel periodicity of sexual communication. Using capture times of beetles in pheromone-baited traps as a proxy for sexual communication periods, our data show that L. canus and L. californicus have seasonally distinct communication periods. Most L. canus males (>90%) were captured in April and most L. californicus males (>95%) were captured in May/June/July. As almost exclusively L. infuscatus males were captured in two separate 24-hr trapping studies, with data recordings every hour, it remains inconclusive whether the three Limonius congeners communicate at different times of the day. Males of L. infuscatus responded to pheromone lures only during daytime hours and during the warmest period each day. Captures of L. infuscatus overlapping with those of L. canus in April and those of L. californicus in May/June imply the presence of reproductive isolating mechanisms other than seasonal separation of sexual communication periods. DOI PubMed
251. Meraj, S; Dhari, AS; Mohr, E; Lowenberger, C; Gries, G. (2022) Characterization of New Defensin Antimicrobial Peptides and Their Expression in Bed Bugs in Response to Bacterial Ingestion and Injection.Int. J. Mol. Sci. 23 Characterization of New Defensin Antimicrobial Peptides and Their Expression in Bed Bugs in Response to Bacterial Ingestion and Injection
bed bugs; defensin antimicrobial peptides; humoral innate immunity; hematophagy; Toll and IMD pathways; vectors; pathogens; immunization
Common bed bugs, Cimex lectularius, can carry, but do not transmit, pathogens to the vertebrate hosts on which they feed. Some components of the innate immune system of bed bugs, such as antimicrobial peptides (AMPs), eliminate the pathogens. Here, we determined the molecular characteristics, structural properties, and phylogenetic relatedness of two new defensins (CL-defensin1 (XP_024085718.1), CL-defensin2 (XP_014240919.1)), and two new defensin isoforms (CL-defensin3a (XP_014240918.1), CL-defensin3b (XP_024083729.1)). The complete amino acid sequences of CL-defensin1, CL-defensin2, CL-defensin3a, and CL-defensin3b are strongly conserved, with only minor differences in their signal and pro-peptide regions. We used a combination of comparative transcriptomics and real-time quantitative PCR to evaluate the expression of these defensins in the midguts and the rest of the body of insects that had been injected with bacteria or had ingested blood containing the Gram-positive (Gr+) bacterium Bacillus subtilis and the Gram-negative (Gr-) bacterium Escherichia coli. We demonstrate, for the first time, sex-specific and immunization mode-specific upregulation of bed bug defensins in response to injection or ingestion of Gr+ or Gr- bacteria. Understanding the components, such as these defensins, of the bed bugs' innate immune systems in response to pathogens may help unravel why bed bugs do not transmit pathogens to vertebrates. DOI PubMed
250. Renyard, A; Gries, R; Cooper, SL; Gooding, CE; Breen, JC; Alamsetti, SK; Munoz, A; Gries, G. (2022) Floral and Bird Excreta Semiochemicals Attract Western Carpenter Ants.Front. Ecol. Evol. 10 Floral and Bird Excreta Semiochemicals Attract Western Carpenter Ants
Hymenoptera; Formicidae; foraging; olfactory cues; semiochemicals; odorants; ant behavior
Ant colonies have vast and diverse nutritional needs but forager ants have limited mobility to meet these needs. Forager ants would accrue significant energy savings if they were able to sense and orient toward odor plumes of both carbohydrate and protein food sources. Moreover, if worker ants, like other flightless insects, had reduced olfactory acuity, they would not recognize the specific odor signatures of diverse carbohydrate and protein sources, but they may be able to orient toward those odorants that are shared between (macronutrient) food sources. Using the Western carpenter ant, Camponotus modoc, as a model species, we tested the hypotheses that (1) food sources rich in carbohydrates (aphid honeydew, floral nectar) and rich in proteins (bird excreta, house mouse carrion, cow liver infested or not with fly maggots) all prompt long-distance, anemotactic attraction of worker ants, and (2) attraction of ants to plant inflorescences (fireweed, Chamaenerion angustifolium; thimbleberry, Rubus parviflorus; and hardhack, Spiraea douglasii) is mediated by shared floral odorants. In moving-air Y-tube olfactometer bioassays, ants were attracted to two of four carbohydrate sources (thimbleberry and fireweed), and one of four protein sources (bird excreta). Headspace volatiles of these three attractive sources were analyzed by gas chromatography-mass spectrometry, and synthetic odor blends of thimbleberry (7 components), fireweed (23 components), and bird excreta (38 components) were prepared. In Y-tube olfactometer bioassays, synthetic blends of thimbleberry and fireweed but not of bird excreta attracted ants, indicating that only the two floral blends contained all essential attractants. A blend of components shared between thimbleberry and fireweed was not attractive to ants. Our data support the conclusion that C. modoc worker ants can sense and orient toward both carbohydrate and protein food sources. As ants were selective in their responses to carbohydrate and protein resources, it seems that they can discern between specific food odor profiles and that they have good, rather than poor, olfactory acuity. DOI
249. Singleton, K; Gries, R; van Herk, WG; Alamsetti, SK; Lemke, E; Furtado, K; Gries, G. (2022) Identification of the Major Sex Pheromone Component of the Click Beetle Agriotes ferrugineipennis.J. Chem. Ecol. 48: 491-501 Identification of the Major Sex Pheromone Component of the Click Beetle <i>Agriotes ferrugineipennis</i>
Click beetles; Elateridae; Agriotes ferrugineipennis; Sex pheromone; Identification; 7-methyloctyl 7-methyloctanoate
Synthetic sex pheromone lures are useful tools to monitor and control populations of adult click beetles (Coleoptera: Elateridae). However, sex pheromones for Agriotes click beetle species native to North America have yet to be identified. Here we report the identification and field testing of the sex pheromone of Agriotes ferrugineipennis. Headspace volatiles from female beetles were collected on Porapak Q, and aliquots of Porapak extract were analyzed by gas chromatographic-electroantennographic detection (GC-EAD) and GC-mass spectrometry. 7-Methyloctyl 7-methyloctanoate (7Me7Me) emitted by females was more abundant and elicited much stronger responses from male antennae than the aldehydes octanal and nonanal and the ketone 6,10,14-trimethyl-2-pentadecanone. In a field experiment, captures of A. ferrugineipennis males in traps baited with candidate pheromone components exceeded those of unbaited control traps, on average by nearly 1,200 times. Neither the ketone nor the aldehydes as lure constituents appeared to alter captures of males in 7Me7Me-baited traps. We conclude that 7Me7Me is the major, and possibly the only, sex attractant pheromone component of female A. ferrugineipennis. DOI PubMed
247. Blake, AJ; Couture, S; Go, MC; Gries, G. (2021) Approach trajectory and solar position affect host plant attractiveness to the small white butterfly.Vision Res. 186: 140-149 Approach trajectory and solar position affect host plant attractiveness to the small white butterfly
Photo polarimetry; Polarization vision; Axis of polarization; Degree of linear polarization; Modeling
While it is well documented that insects exploit polarized sky light for navigation, their use of reflected polarized light for object detection has been less well studied. Recently, we have shown that the small white butterfly, Pieris rapae, distinguishes between host and non-host plants based on the degree of linear polarization (DoLP) of light reflected from their leaves. To determine how polarized light cues affect host plant foraging by female P. rapae across their entire visual range including the ultraviolet (300-650 nm), we applied photo polarimetry demonstrating large differences in the DoLP of leaf-reflected light among plant species generally and between host and non-host plants specifically. As polarized light cues are directionally dependent, we also tested, and modelled, the effect of approach trajectory on the polarization of plant-reflected light and the resulting attractiveness to P. rapae. Using photo polarimetry measurements of plants under a range of light source and observer positions, we reveal several distinct effects when polarized reflections are examined on a whole-plant basis rather than at the scale of pixels or plant canopies. Most notably from our modeling, certain approach trajectories are optimal for foraging butterflies, or insects generally, to discriminate between plant species on the basis of the DoLP of leaf-reflected light. DOI PubMed
246. Chalissery, JM; Gries, R; Alamsetti, SK; Ardiel, MJ; Gries, G. (2021) Identification of the Trail Pheromone of the Pavement Ant Tetramorium immigrans (Hymenoptera: Formicidae).J. Chem. Ecol.Identification of the Trail Pheromone of the Pavement Ant <i>Tetramorium immigrans</i> (Hymenoptera: Formicidae)
Myrmicinae; Communication; Gas chromatographic-electroantennographic detection; Trail-following; Field testing
Four species of <i>Tetramorium</i> pavement ants are known to guide foraging activities of nestmates via trail pheromones secreted from the poison gland of worker ants, but the trail pheromone of T. immigrans is unknown. Our objectives were to (1) determine whether poison gland extract of T immigrans workers induces trail-following behavior of nestmates, (2) identify the trail pheromone, and (3) test whether synthetic trail pheromone induces trail-following behavior of workers. In laboratory no-choice bioassays, ants followed poison-gland-extract trails farther than they followed whole-body-extract trails or solvent-control trails. Gas chromatographic-electroantennographic detection (GC-EAD) analyses of poison gland extract revealed a single candidate pheromone component (CPC) that elicited responses from worker ant antennae. The CPC mass spectrum indicated, and an authentic standard confirmed, that the CPC was methyl 2-methoxy-6-methylbenzoate (MMMB). In further laboratory no-choice bioassays, ants followed poison-gland-extract trails (tested at 1 ant equivalent) and synthetic MMMB trails (tested at 0.35 ant equivalents) equally far, indicating that MMMB is the single-component trail pheromone of T. immigrans. Moreover, in laboratory two-choice bioassays, ants followed MMMB trails similar to 21-times farther than solvent-control trails. In field settings, when T. immigrans colonies were offered a choice between two paper strips treated with a synthetic MMMB trail or a solvent-control trail, each leading to an apple bait, the MMMB trails efficiently recruited nestmates to baits. DOI PubMed
245. Fischer, A; Lee, Y; Don, T; Gries, G. (2021) Know your foe: synanthropic spiders are deterred by semiochemicals of European fire ants.R. Soc. Open Sci. 8 Know your foe: synanthropic spiders are deterred by semiochemicals of European fire ants
ant cue; spider deterrent; integrated pest management; Myrmica rubra
Many ants prey on spiders, suggesting that web-building spiders may avoid micro-locations near ant colonies or frequented by foraging ants. Here we tested the hypothesis that ant-derived semiochemicals deter synanthropic spiders. To generate stimuli, we exposed filter paper for 12 h to workers of European fire ants, Myrmica rubra, black garden ants, Lasius niger, or western carpenter ants, Camponotus modoc, and then offered select urban spiders in three-chamber olfactometer bioassays a choice between ant-exposed filter paper and unexposed control filter paper. Semiochemical deposits of M. rubra, but not of L. niger or C. modoc, had a significant deterrent effect on subadults of the false black widow, Steatoda grossa, the black widow, Latrodectus hesperus, and the hobo spider, Eratigena agrestis, as well as a moderate (but statistically not significant) deterrent effect on the cross spider, Araneus diadematus. The deterrent effect caused by semiochemical deposits of M. rubra may be attributable to the aggressive nature and efficient foraging of M. rubra in its invaded North American range, exerting selection pressure on community members to recognize M. rubra semiochemicals and to avoid micro-locations occupied by M. rubra. DOI PubMed
244. Fischer, A; MacLennan, S; Gries, R; Gries, G. (2021) Herbivore-induced plant volatiles do not affect settling decisions by synanthropic spiders.Chemoecology 31: 201-208 Herbivore-induced plant volatiles do not affect settling decisions by synanthropic spiders
Synanthropic spiders; Herbivore-induced plant volatiles; Multi-trophic interaction; HIPV-based spider deterrents
An underlying assumption of optimal foraging models is that animals are behaviorally, morphologically, and physiologically adapted to maximize their net energy intake. Here we explored whether this concept applies to web-building spiders in a multi-trophic context. If a spider were to build her web next to herbivore-fed-on plants that signal the herbivores' enemies for help by emitting herbivore-induced plant volatiles (HIPVs), that spider may maximize web captures in the short term. However, she would also risk predation by generalist predators that "listen" to signaling plants to find both herbivore and spider prey, likely resulting in lower overall reproductive fitness for the spider. We tested the hypothesis that HIPVs trigger avoidance responses by web-building spiders. We selected seven common HIPVs and one HIPV elicitor, and in two-choice olfactometer bioassays tested their effect on four synanthropic spider species (false black widow, Steatoda grossa; common cellar spider, Pholcus phalangioides; hobo spider, Eratigena agrestis; western black widow, Latrodectus hesperus). The 8-component HIPV/HIPV elicitor blend had a weak deterrent effect on S. grossa, but the effect did not extend to P. phalangioides, E. agrestis, and L. hesperus. Our findings imply that there was insufficient selection pressure for these spiders to recognize HIPVs in a multi-trophic context, where spiders themselves could become prey if generalist predators or spider-hunting parasitoid wasps were to respond to signaling plants. DOI
243.Gries, R; Alamsetti, SK; van Herk, WG; Catton, HA; Meers, S; Lemke, E; Gries, G. (2021) Limoniic Acid-Major Component of the Sex Pheromones of the Click Beetles Limonius canus and L. californicus.J. Chem. Ecol. 47: 123-133 Limoniic Acid-Major Component of the Sex Pheromones of the Click Beetles Limonius canus and L. californicus
Wireworms; Elaterid beetles; (E)-4-Ethyloct-4-enoic acid; (E)-5-Ethyloct-4-enoic acid; GC-EAD; GC-MS; Limonius infuscatus
Wireworms, the larvae of click beetles (Coleoptera: Elateridae), are soil-dwelling insect pests inflicting major economic damage on many types of agricultural crops worldwide. The objective of this work was to identify the female-produced sex pheromones of the Pacific Coast wireworm, Limonius canus LeConte, and the sugarbeet wireworm, L. californicus (Mannerheim) (Coleoptera: Elateridae). Headspace volatiles from separate groups of female L. canus and L. californicus were collected on Porapak Q and analyzed by gas chromatography with electroantennographic detection (GC-EAD) and GC-mass spectrometry. GC-EAD recordings revealed strong responses from male L. canus and male L. californicus antennae to the same compound, which appeared below GC detection threshold. The structure of this candidate pheromone component was deduced from the results of micro-analytical treatments of extracts, retention index calculations on four GC columns, and by syntheses of more than 25 model compounds which were assessed for their GC retention characteristics and electrophysiological activity. The EAD-active compound was identified as (E)-4-ethyloct-4-enoic acid, which we name limoniic acid. In field experiments in British Columbia and Alberta, Canada, traps baited with synthetic limoniic acid captured large numbers of male Limonius click beetles, whereas unbaited control traps captured few. Compared to traps baited with the analogue, (E)-5-ethyloct-4-enoic acid, traps baited with limoniic acid captured 9-times more male L. californicus, and 6.5-times more male western field wireworms, L. infuscatus Motschulsky, but 2.3-times fewer male L. canus. Limoniic acid can now be developed for detection, monitoring and possibly control of L. californicus, L. infuscatus and L. canus populations. DOI PubMed
242. Hoefele, D; Chalissery, JM; Renyard, A; Gries, G. (2021) Experimentally guided development of a food bait for European fire ants.Entomol. Exp. Appl. 169: 780-791 Experimentally guided development of a food bait for European fire ants
European fire ants; Myrmica rubra; Myrmicinae; Formicidae; invasive species; foraging ecology; food bait; insect pest management; lethal food; shelf life; foraging response; cost‐ effective
Deployment of lethal food baits could become a control tactic for the invasive European fire ant (EFA), Myrmica rubra L. (Hymenoptera: Formicidae), because foraging ants carry the lethal food to their nest and share it with their nest mates, ultimately causing the demise of nests. Our objective was to develop a food bait that elicits a strong foraging response from EFAs, has extended shelf life, and is cost-effective to produce. To develop a bait composition with 'ant appeal', we ran two separate field experiments testing pre-selected carbohydrate sources (oranges, apples, bananas) and protein/lipid sources [tuna, pollen, sunflower seeds, mealworms (Tenebrio molitor L., Coleoptera: Tenebrionidae)]. Whereas foraging EFAs responded equally well to the three types of carbohydrates, they preferred mealworms to all other protein/lipid sources. In a follow-up laboratory experiment, the combination of apples and mealworms elicited a stronger foraging response from EFAs than either apples or mealworms alone. To help reduce bait ingredient costs, we tested house crickets, Acheta domesticus (L.) (Orthoptera: Gryllidae), as a less expensive mealworm alternative and found crickets and mealworms comparably appealing. Addressing the shelf life of baits, we tested freeze-dried and heat-dried apple/cricket combinations. Rehydrated freeze-dried baits proved as appealing as fresh baits and superior to rehydrated heat-dried baits, suggesting that freeze-drying may retain essential nutrients and/or aroma constituents. Insecticide-laced baits had no off-putting effect on foraging responses of worker ants and caused significant mortality. As freeze-drying is expensive, further research should investigate the preservation of moist food baits or the development of dry baits that are hydrated prior to deployment. DOI
241. Meraj, S; Mohr, E; Ketabchi, N; Bogdanovic, A; Lowenberger, C; Gries, G. (2021) Time- and tissue-specific antimicrobial activity of the common bed bug in response to blood feeding and immune activation by bacterial injection.J. Insect Physiol. 135 Time- and tissue-specific antimicrobial activity of the common bed bug in response to blood feeding and immune activation by bacterial injection
Bed bug; Aedes aegypti; Midgut; Antimicrobial peptide activity; Immune activation; Blood feeding
Unlike almost all hematophagous insects, common bed bugs, Cimex lectularius, are not known to transmit pathogens to humans. To help unravel the reasons for their lack of vector competence, we studied the time-and tissue-dependent expression of innate immune factors after blood feeding or immune activation through the intrathoracic injection of bacteria. We used minimum inhibitory concentration (MIC1) bioassays and the Kirby Bauer protocol to evaluate antimicrobial peptide (AMP(2)) activity in tissue extracts from the midguts or 'rest of body' (RoB(3)) tissues (containing hemolymph and fat body AMPs) against Gram-positive and Gram-negative bacteria. We compared AMP activity between blood-fed female bed bugs and yellow fever mosquitoes, Aedes aegypti and determined how female and male bed bugs respond to immune challenges, and how long AMP gene expression remains elevated in bed bugs following a blood meal. Blood meal-induced AMP activity is 4-fold stronger in female bed bugs than in female mosquitoes. Male bed bugs have elevated AMP activity within 8 h of a blood meal or an intrathoracic injection with bacteria, with the strongest activity expressed in RoB tissue 24 h after the immune challenge. Female bed bugs have a stronger immune response than males within 24 h of a blood meal. The effects of blood meal-induced elevated AMP activity lasts longer against the Gram-positive bacterium, Bacillus subtilis, than against the Gram-negative bacterium Escherichia coli. Unravelling the specific immune pathways that are activated in the bed bugs' immune responses and identifying the bed bug-unique AMPs might help determine why these insects are not vectors of human parasites. DOI PubMed
239. Peach, DAH; Almond, M; Ko, E; Meraj, S; Gries, R; Gries, G. (2021) Cheese and cheese infusions: ecological traps for mosquitoes and spotted wing Drosophila.Pest Manag. Sci. 77: 5599-5607 Cheese and cheese infusions: ecological traps for mosquitoes and spotted wing Drosophila
ecological traps; integrated pest management; mosquito control; cheese; Culex pipiens; Drosophila suzukii
BACKGROUND Harnessing insect ecology for insect control is an innovative concept that seeks to exploit, among others, insect-microbe ecological interactions for improved control of pest insects. Microbe-produced cheese odour attracts several dipterans, including host-seeking mosquitoes, but this phenomenon has not been thoroughly explored for mosquito control. Here we tested the hypothesis that attraction of mosquitoes to cheese odour can be exploited as an ecological trap for mosquito control. RESULTS In laboratory and/or field experiments, we show that (i) each of five cheese varieties tested (Raclette, Pecorino, Brie, Gruyere, Limburger) strongly attracts female Aedes aegypti and Culex pipiens; (ii) cheese infusions, or headspace odourant extracts (HOEs) of cheese infusions, significantly affect oviposition choices by mosquitoes, (iii) HOEs contain at least 13 odourants; (iv) in field settings, cheese infusions more effectively stimulate mosquito oviposition than positive bluegrass infusion controls, and also capture (by drowning) the spotted wing Drosophila, Drosophila suzukii; and (v) home-made cheese infusions modulate oviposition choices by mosquito females and affect the survivorship of their offspring larvae. CONCLUSION Our data show that microbial metabolites associated with cheese are attractive to mosquito females seeking hosts and oviposition sites and are likely toxic to mosquito larvae. These microbes and their metabolites could thus be co-opted for both the attract, and the kill, function of 'attract & kill' mosquito control tactics. Implementation of customizable and non-conventional nutritional media as microbe-based ecological traps presents a promising concept which exploits insect ecology for insect control. DOI PubMed
238. Renyard, A; Gries, R; Lee, J; Chalissery, JM; Damin, S; Britton, R; Gries, G. (2021) All sugars ain't sweet: selection of particular mono-, di- and trisaccharides by western carpenter ants and European fire ants.R. Soc. Open Sci. 8 All sugars ain't sweet: selection of particular mono-, di- and trisaccharides by western carpenter ants and European fire ants
hymenoptera; formicidae; foraging; mutualism; ant-aphid interaction; nest-mate recruitment
Ants select sustained carbohydrate resources, such as aphid honeydew, based on many factors including sugar type, volume and concentration. We tested the hypotheses (H1-H3) that western carpenter ants, Camponotus modoc, seek honeydew excretions from Cinara splendens aphids based solely on the presence of sugar constituents (H1), prefer sugar solutions containing aphid-specific sugars (H2) and preferentially seek sugar solutions with higher sugar content (H3). We further tested the hypothesis (H4) that workers of both Ca. modoc and European fire ants, Myrmica rubra, selectively consume particular mono-, di- and trisaccharides. In choice bioassays with entire ant colonies, sugar constituents in honeydew (but not aphid-specific sugar) as well as sugar concentration affected foraging decisions by Ca. modoc. Both Ca. modoc and M. rubra foragers preferred fructose to other monosaccharides (xylose, glucose) and sucrose to other disaccharides (maltose, melibiose, trehalose). Conversely, when offered a choice between the aphid-specific trisaccharides raffinose and melezitose, Ca. modoc and M. rubra favoured raffinose and melezitose, respectively. Testing the favourite mono-, di- and trisaccharide head-to-head, both ant species favoured sucrose. While both sugar type and sugar concentration are the ultimate cause for consumption by foraging ants, strong recruitment of nest-mates to superior sources is probably the major proximate cause. DOI PubMed
237. Takacs, S; Gries, G. (2021) Phonotactic responses of Brown Rats (Rattus norvegicus) to begging calls of Starling nestlings (Sturnus vulgaris).J. Ornithol. 162: 1173-1181 Phonotactic responses of Brown Rats (Rattus norvegicus) to begging calls of Starling nestlings (Sturnus vulgaris)
Opportunistic omnivore; Foraging cue; Acoustic eavesdropping; Vocalization; Predation behavior; Bird conservation
Foraging behavior of Brown Rats (Rattus norvegicus) is commonly thought to be guided by olfactory cues. Here we tested the hypothesis that foraging Brown Rats eavesdrop on bird vocalizations to locate prey. We recorded calls of nestling Starlings (Sturnus vulgaris) with microphones sensitive in the sonic and ultrasonic range, respectively, and compiled clear begging calls into a single sound file (2-min long) which included the entire recorded sound range (0-100 kHz; Audio File 1). Sound analyses revealed a fundamental two-tone modulated sound centered around 3 kHz, a first and second harmonic at, respectively, 9 and 16 kHz, and bands of ultrasonic frequency components at 20, 25, and 37 kHz. We subjected Audio File 1 to low- and highpass-filtering, thereby producing a sonic-range only file (< 20 kHz; Audio File 2), and an ultrasonic-range only file (20-100 kHz; Audio File 3). In binary-choice large arena bioassays, we then tested the behavioral responses of single Brown Rats to paired trap boxes each fitted with a speaker, one of which emitting a white noise control and the other playing back Audio File 1 (Exp. 1), Audio File 2 (Exp. 2), or Audio File 3. In each of experiments 1-3, female and male rats (i) significantly more often entered first the trap box broadcasting an Audio File, and (ii) spent significantly more time in the arena quadrant with an Audio File trap box. Our data support the conclusion that foraging Brown Rats, as opportunistic omnivores, exploit begging calls of nestling Starlings, and possibly other birds, as cues to obtain a proteinaceous meal. DOI
236. Takacs, S; Kowalski, P; Gries, G. (2021) Vocalizations of infant brown rats, but not infant house mice, enhance rodent captures in sex pheromone-baited traps.Appl. Anim. Behav. Sci. 236 Vocalizations of infant brown rats, but not infant house mice, enhance rodent captures in sex pheromone-baited traps
House mouse pups; Brown rat pups; Vocalizations; Sex pheromone; Trap captures; Rat management
Synthetic replica of rat pup, Rattus norvegicus, vocalizations reportedly increase captures of wild rats in traps baited with natural scent of adult female rats. Here we tested the hypotheses (1) that synthetic calls of house mouse pups, Mus musculus, increase captures of wild house mice in traps baited with synthetic sex pheromones of mice, and (2) that synthetic rat pup calls increase captures of wild rats in traps baited with synthetic rat sex pheromones. Analyses of vocalizations from isolated 2- to 4-day-old mouse pups revealed frequency components almost exclusively in the ultrasonic range. In laboratory experiments, playback recordings of these calls, and synthetic replica thereof, each tested versus a silent control or a constant 60-kHz tone, induced phonotactic, arrestment and speaker-contact responses by both ?pup-experienced? and ?pup-na?ve? adult female and adult male mice. In field experiments, synthetic mouse pup calls had no effect on captures of adult and juvenile male mice in female mouse pheromone-baited traps, and reduced captures of juvenile female mice in male mouse pheromone-baited traps. In analogous field experiments with brown rats, traps baited with both synthetic rat pup calls and synthetic rat sex pheromones captured 3.75-times (15 vs 4) more male rats and 2.5-times (15 vs 6) more female rats than traps baited with synthetic sex pheromone alone. We show that synthetic mouse pup vocalizations cannot be exploited as a trap lure to enhance trap captures of mice. Conversely, synthetic rat pup vocalizations enhance the attractiveness of synthetic sex pheromone lures to male and female rats and could become part of integrated brown rat management. DOI
235. Uriel, Y; Abram, PK; Gries, G. (2021) Parasitoid pressure does not elicit defensive polyphenism in the green peach aphid.Ecol. Entomol. 46: 668-676 Parasitoid pressure does not elicit defensive polyphenism in the green peach aphid
Aphidius colemani; biocontrol; experimental evolution; Myzus persicae; polyphenism; resistance management
1. Aphids are capable of adapting to parasitoid pressure in the absence of sexual reproduction using epigenetically controlled polyphenism. Asexual lineages of aphids could thus become resistant to parasitoids over time and with repeated exposure, hampering biocontrol efforts that rely on parasitoid wasps. 2. Prior to this study, wing polyphenism and reproductive polyphenism had been reported as parasitoid-adaptive responses in asexual lineages of at least two species of aphids, but it remained unclear whether parasitoid exposure could induce other defensive polyphenisms. Using a rigorous, replicated experimental evolution design, we aimed to induce adaptive polyphenisms in the green peach aphid, Myzus persicae Sulzer, through serial exposures of single asexual lines to the parasitoid Aphidius colemani Viereck over four consecutive generations. 3. We measured changes in parasitoid susceptibility, reproductive schedule, body size, and production of pink or alate offspring compared to aphid control lines not exposed to parasitoids. Despite this consistently strong selective parasitoid pressure, there was no evidence that asexual lineages of M. persicae adapt to parasitoid pressure using adaptive polyphenism. 4. Our data indicate that pseudo-crowding stress - where aphids disturbed by parasitoids or predators wander within a colony, increasing aphid-to-aphid contact and creating the illusion of a more crowded environment - may be necessary for M. persicae to produce defensive polyphenisms in response to parasitoid attack. DOI
234. Wong, WHL; Gries, RM; Abram, PK; Alamsetti, SK; Gries, G. (2021) Attraction of Brown Marmorated Stink Bugs, Halyomorpha halys, to Blooming Sunflower Semiochemicals.J. Chem. Ecol. 47: 614-627 Attraction of Brown Marmorated Stink Bugs, Halyomorpha halys, to Blooming Sunflower Semiochemicals
Plant phenology; Pentatomidae; Plant volatile compounds; Olfactometer bioassays; GC-EAD; GC-MS
The polyphagous invasive brown marmorated stink bug, Halyomorpha halys, reportedly discriminates among phenological stages of host plants. To determine whether olfaction is involved in host plant stage discrimination, we selected (dwarf) sunflower, Helianthus annuus, as a model host plant species. When adult females of a still-air laboratory experiment were offered a choice of four potted sunflowers at distinct phenological stages (vegetative, pre-bloom, bloom, seeding), most females settled onto blooming plants but oviposited evenly on plants of all four stages. In moving-air two-choice olfactometer experiments, we then tested each plant stage versus filtered air and versus one another, for attraction of H. halys females. Blooming sunflowers performed best overall, but no one plant stage was most attractive in all experiments. Capturing and analyzing (by GC-MS) the headspace odorants of each plant stage revealed a marked increase of odorant abundance (e.g., monoterpenes) as plants transitioned from pre-bloom to bloom. Analyzing the headspace odorant blend of blooming sunflower by gas chromatographic-electroantennographic detection (GC-EAD) revealed 13 odorants that consistently elicited responses from female H. halys antennae. An 11-component synthetic blend of these odorants attracted H. halys females in laboratory olfactometer experiments. Furthermore, in field settings, the synthetic blend enhanced the attractiveness of synthetic H. halys pheromone as a trap lure, particularly in spring (April to mid-June). A simpler yet fully effective sunflower semiochemical blend could be developed and coupled with synthetic H. halys aggregation pheromones to improve monitoring efforts or could improve the efficacy of modified attract-and-kill control tactics for H. halys. DOI PubMed
232. Fischer, A; Goh, XH; Varney, JLS; Blake, AJ; Takacs, S; Gries, G. (2020) Multimodal and multifunctional signaling? - Web reduction courtship behavior in a North American population of the false black widow spider.PLoS One 15 Multimodal and multifunctional signaling? - Web reduction courtship behavior in a North American population of the false black widow spider
Males of widow spiders courting on the web of females engage in web-reduction behavior which entails excising a section of the web, bundling it up, and wrapping it with their silk. Males of the false black widow spider, Steatoda grossa, in European populations also produce stridulatory courtship sound which has not yet been studied in their invaded North American range. Working with a North American population of S. grossa, we tested the hypotheses that (1) web reduction by males renders webs less attractive to rival males; (2) deposition of silk by courting males has an inter-sexual (male-female) signal function that enhances their likelihood of copulation; and (3) stridulatory sound is a courtship signal of males. Testing anemotactic attraction of males in Y-tube olfactometer experiments revealed that reduced webs (indicative of a mated female) and intact webs (indicative of a virgin female) were equally attractive to males. Recording courtship behavior of males with either functional (silk-releasing) spinnerets or spinnerets experimentally occluded on the web of virgin females showed that males with functional spinnerets were more likely to copulate with the female they courted. Although males possess the stridulatory apparatus to produce courtship sound, they did not stridulate when courting or copulating on the web of females. Our data support the conclusion that web-reduction behavior of S. grossa males in their invaded North American range has no long-range effect on mate seeking males. Instead, web-reduction behavior has an inter-sexual signaling function that seems to be linked to functional spinnerets of the courting male. The signal produced by a male likely entails a volatile silk-borne pheromone, but may also embody a gauge of his endurance (the amount of time he engages in web reduction causing web vibrations). DOI PubMed
231. Fischer, A; Hung, E; Amiri, N; Gries, G. (2020) 'Mine or thine': indiscriminate responses to own and conspecific webs and egg sacs by the false black widow spider, Steatoda grossa (Araneae: Theridiidae).J. Ethol.'Mine or thine': indiscriminate responses to own and conspecific webs and egg sacs by the false black widow spider, Steatoda grossa (Araneae: Theridiidae)
Spider web identity; Spider egg sac identity; Steatoda grossa; False black widow spider
Female false black widows, Steatoda grossa (Araneae: Theridiidae), build energy-costly webs. We tested the hypotheses (H1, H2) that females prefer their own webs and the chemical extract of their own webs to those of conspecifics, and (H3) that mated females discern between their own egg sacs and those of conspecifics. In choice bioassays, females indiscriminately accepted both their own webs and egg sacs and those of conspecific females, although they chose extracts of webs based on their chemical cues. The females' indiscriminate responses to webs or egg sacs are likely due to a lack of selection pressure to reject webs or egg sacs of conspecific females. DOI
229. Renyard, A; Gries, R; Gries, G. (2020) A blend of formic acid, benzoic acid, and aliphatic alkanes mediates alarm recruitment responses in western carpenter ants, Camponotus modoc.Entomol. Exp. Appl. 168: 311-321 A blend of formic acid, benzoic acid, and aliphatic alkanes mediates alarm recruitment responses in western carpenter ants, Camponotus modoc
Hymenoptera; Formicidae; attraction; communication; exocrine gland; recruitment signal; Y-tube olfactometer; GC-MS; poison gland; arena assay; Dufour's gland
Formicine ants in distress spray alarm pheromone which typically recruits nestmates for help. Studying the western carpenter ant, Camponotus modoc Wheeler (Hymenoptera: Formicidae), our objectives were to (1) determine the exocrine glands that contain alarm recruitment pheromone, (2) identify the key alarm recruitment pheromone components, and (3) ascertain the pheromone components that are discharged by distressed ants. In Y-tube olfactometer experiments, extracts of poison glands, but not of Dufour's glands, elicited anemotactic responses from worker ants. Gas chromatographic-mass spectrometric analyses of poison gland extracts revealed the presence of (1) aliphatic alkanes (undecane, tridecane, pentadecane, heptadecane), (2) aliphatic alkenes [(Z)-7-pentadecene, (Z)-7- and (Z)-8-heptadecene], (3) two acids (formic, benzoic), and (4) other oxygenated compounds (hexadecan-1-ol, hexadecyl formate, hexadecyl acetate). Testing the responses of worker ants in Y-tube olfactometers to complete and partial synthetic blends of these compounds revealed that the acids and the alkanes are essential alarm pheromone components. In two-choice arena bioassays, micro-locations treated with synthetic alarm pheromone recruited worker ants. Acids and alkanes were abundant in the poison gland and the Dufour's gland, respectively, suggesting that the alarm pheromone components originate from both glands. Moreover, alarm pheromone sprays of ants differed in that all sprays contained formic acid but only some also contained alkanes, implying that ants can independently discharge the content of either one or both glands in accordance with the type of distress incident they experience. DOI
228. Uriel, Y; Gries, R; Tu, L; Carroll, C; Zhai, HM; Moore, M; Gries, G. (2020) The fly factor phenomenon is mediated by interkingdom signaling between bacterial symbionts and their blow fly hosts.Insect Sci. 27: 256-265 The fly factor phenomenon is mediated by interkingdom signaling between bacterial symbionts and their blow fly hosts
blow flies; enteric bacteria; fly factor; interkingdom communication; microbial symbionts; semiochemical attractants
We tested the recent hypothesis that the "fly factor" phenomenon (food currently or previously fed on by flies attracts more flies than the same type of food kept inaccessible to flies) is mediated by bacterial symbionts deposited with feces or regurgitated by feeding flies. We allowed laboratory-reared black blow flies, Phormia regina (Meigen), to feed and defecate on bacterial Luria-Bertani medium solidified with agar, and isolated seven morphologically distinct bacterial colonies. We identified these using matrix-assisted laser desorption/ionization mass spectrometry and sequencing of the 16S rRNA gene. In two-choice laboratory experiments, traps baited with cultures of Proteus mirabilis Hauser, Morganella morganii subsp. sibonii Jensen, or Serratia marcescens Bizio, captured significantly more flies than corresponding control jars baited with tryptic soy agar only. A mixture of seven bacterial strains as a trap bait was more attractive to flies than a single bacterial isolate (M. m. sibonii). In a field experiment, traps baited with agar cultures of P. mirabilis and M. m. sibonii in combination captured significantly more flies than traps baited with either bacterial isolate alone or the agar control. As evident by gas chromatography-mass spectrometry, the odor profiles of bacterial isolates differ, which may explain the additive effect of bacteria to the attractiveness of bacterial trap baits. As "generalist bacteria," P. mirabilis and M. m. sibonii growing on animal protein (beef liver) or plant protein (tofu) are similarly effective in attracting flies. Bacteria-derived airborne semiochemicals appear to mediate foraging by flies and to inform their feeding and oviposition decisions. DOI PubMed
227. Varner, E; Jackson, H; Mahal, M; Takacs, S; Gries, R; Gries, G. (2020) Brown rats and house mice eavesdrop on each other's volatile sex pheromone components.Sci Rep 10 Brown rats and house mice eavesdrop on each other's volatile sex pheromone components
Mammalian pheromones often linger in the environment and thus are particularly susceptible to interceptive eavesdropping, commonly understood as a one-way dyadic interaction, where prey sense and respond to the scent of a predator. Here, we tested the "counterespionage" hypothesis that predator and prey co-opt each other's pheromone as a cue to locate prey or evade predation. We worked with wild brown rats (predator of mice) and wild house mice (prey of brown rats) as model species, testing their responses to pheromone-baited traps at infested field sites. The treatment trap in each of two trap pairs per replicate received sex attractant pheromone components (including testosterone) of male mice or male rats, whereas corresponding control traps received only testosterone, a pheromone component shared between mouse and rat males. Trap pairs disseminating male rat pheromone components captured 3.05 times fewer mice than trap pairs disseminating male mouse pheromone components, and no female mice were captured in rat pheromone-baited traps, indicating predator aversion. Indiscriminate captures of rats in trap pairs disseminating male rat or male mouse pheromone components, and fewer captures of rats in male mouse pheromone traps than in (testosterone-only) control traps indicate that rats do eavesdrop on the male mouse sex pheromone but do not exploit the information for mouse prey location. The counterespionage hypothesis is supported by trap catch data of both mice and rats but only the mice data are in keeping with our predictions for motive of the counterespionage. DOI PubMed
226. Babcock, T; Borden, JH; Gries, R; Carroll, C; Lafontaine, JP; Moore, M; Gries, G. (2019) Inter-kingdom signaling - symbiotic yeasts produce semiochemicals that attract their yellowjacket hosts.Entomol. Exp. Appl. 167 Inter-kingdom signaling - symbiotic yeasts produce semiochemicals that attract their yellowjacket hosts
Vespula pensylvanica; yeast symbiosis; Hanseniaspora uvarum; Lachancea thermotolerans; Hymenoptera; Vespidae
In recent studies, the yeast species Hanseniaspora uvarum and Lachancea thermotolerans were isolated from the digestive tract of four North American yellowjacket species (Hymenoptera: Vespidae), and attraction of yellowjackets to brewer's yeast, Saccharomyces cerevisiae (all Saccharomycetaceae), growing on fruit powder was demonstrated. We tested the hypothesis that Vespula spp. are attracted to cultures of H. uvarum and L. thermotolerans and their respective volatiles. In field experiments, we found that H. uvarum and L. thermotolerans are attractive to three species of yellowjacket, but only when grown on grape juice-infused yeast peptone dextrose (YPD) agar. Using gas chromatography-mass spectrometry, we analyzed the headspace volatiles produced by these yeasts, and field tested an 18-component yeast synthetic semiochemical blend. This synthetic blend attracted western yellowjackets, Vespula pensylvanica (Saussure), but no other yellowjacket species. Acetic acid or ethanol added to the synthetic blend at biologically relevant doses either had no effect or significantly lowered trap captures. Our results demonstrate that yeast symbionts isolated from the digestive tract of yellowjackets are attractive to their hosts. Further research is needed to identify the volatiles mediating attraction of species other than V. pensylvanica to the yeast cultures. DOI
225. Blake, AJ; Go, MC; Hahn, GS; Grey, H; Couture, S; Gries, G. (2019) Polarization of foliar reflectance: novel host plant cue for insect herbivores.Proc. R. Soc. B-Biol. Sci. 286 Polarization of foliar reflectance: novel host plant cue for insect herbivores
butterfly; insect vision; polarization vision; photoreceptor; degree of linear polarization; Pieris rapae
Insect herbivores exploit plant cues to discern host and non-host plants. Studies of visual plant cues have focused on colour despite the inherent polarization sensitivity of insect photoreceptors and the information carried by polarization of foliar reflectance, most notably the degree of linear polarization (DoLP; 0-100%). The DoLP of foliar reflection was hypothesized to be a host plant cue for insects but was never experimentally tested. Here, we show that cabbage white butterflies, Pieris rapae (Pieridae), exploit the DoLP of foliar reflections to discriminate among plants. In experiments with paired digital plant images, P. rapae females preferred images of the host plant cabbage with a low DoLP (31%) characteristic of cabbage foliage over images of a non-host potato plant with a higher DoLP (50%). By reversing the DoLP of these images, we were able to shift the butterflies' preference for the cabbage host plant image to the potato non-host plant image, indicating that the DoLP had a greater effect on foraging decisions than the differential colour, intensity, or shape of the two plant images. Although previously not recognized, the DoLP of foliar reflection is an essential plant cue that may commonly be exploited by foraging insect herbivores. DOI PubMed
224. Blake, AJ; Pirih, P; Qiu, XD; Arikawa, K; Gries, G. (2019) Compound eyes of the small white butterfly Pieris rapae have three distinct classes of red photoreceptors.J. Comp. Physiol. A -Neuroethol. Sens. Neural Behav. Physiol. 205: 553-565 Compound eyes of the small white butterfly Pieris rapae have three distinct classes of red photoreceptors
Spectral sensitivity; Polarization sensitivity; Fluorescence; Pigments; Phylogeny
The two subspecies of the small white butterfly, the European Pieris rapae rapae and the Asian P. r. crucivora, differ in wing colouration. Under ultraviolet light, the wings of both male and female P. r. rapae appear dark, whereas the wings of male P. r. crucivora are dark and those of females are bright. It has been hypothesized that these sexually dimorphic wing reflections in P. r. crucivora may have induced the evolution of a fluorescing-screening pigment in the violet-opsin-expressing photoreceptors of males, thus facilitating greater wavelength discrimination near 400nm. Comparing the compound eyes of the two subspecies using genetic, microscopical, spectrographic, and histological methods revealed no differences that would meaningfully affect photoreceptor sensitivity, suggesting that the fluorescing-screening pigment did not evolve in response to sexually dimorphic wing reflections. Our investigation further revealed that (i) the peri-rhabdomal reddish-screening pigments differ among the three ommatidial types; (ii) each of the ommatidial types exhibits a unique class of red photoreceptor with a distinct spectral peak; and (iii) the blue, green, and red photoreceptors of P. rapae exhibit a polarization sensitivity >2, with red photoreceptors allowing for a two-channel opponency form of polarization sensitivity. DOI PubMed
223. Chalissery, JM; Renyard, A; Gries, R; Hoefele, D; Alamsetti, SK; Gries, G. (2019) Ants Sense, and Follow, Trail Pheromones of Ant Community Members.Insects 10 Ants Sense, and Follow, Trail Pheromones of Ant Community Members
Lasius niger; black garden ant; Camponotus modoc; Western carpenter ant; Myrmica rubra; European fire ant; trail pheromone; eavesdropping; pheromonal communication; gas chromatographic-electroantennographic detection
Ants deposit trail pheromones that guide nestmates to food sources. We tested the hypotheses that ant community members (Western carpenter ants, Camponotus modoc; black garden ants, Lasius niger; European fire ants, Myrmica rubra) (1) sense, and follow, each other's trail pheromones, and (2) fail to recognize trail pheromones of allopatric ants (pavement ants, Tetramorium caespitum; desert harvester ants, Novomessor albisetosus; Argentine ants, Linepithema humilis). In gas chromatographic-electroantennographic detection analyses of a six-species synthetic trail pheromone blend (6-TPB), La. niger, Ca. modoc, and M. rubra sensed the trail pheromones of all community members and unexpectedly that of T. caespitum. Except for La. niger, all species did not recognize the trail pheromones of N. albisetosus and Li. humilis. In bioassays, La. niger workers followed the 6-TPB trail for longer distances than their own trail pheromone, indicating an additive effect of con- and hetero-specific pheromones on trail-following. Moreover, Ca. modoc workers followed the 6-TPB and their own trail pheromones for similar distances, indicating no adverse effects of heterospecific pheromones on trail-following. Our data show that ant community members eavesdrop on each other's trail pheromones, and that multiple pheromones can be combined in a lure that guides multiple species of pest ants to lethal food baits. DOI PubMed
222. Fischer, A; Hung, E; Gries, G. (2019) Female false black widow spiders, Steatoda grossa, recognize webs based on physical and chemical cues.Entomol. Exp. Appl. 167: 803-810 Female false black widow spiders, Steatoda grossa, recognize webs based on physical and chemical cues
habitat choice; web recognition; structural support hypothesis; Araneae; Theridiidae; semiochemicals; habitat suitability
Females of the false black widow, Steatoda grossa CL Koch (Araneae: Theridiidae), invest significant energy and time weaving cobwebs. We tested the hypothesis that S. grossa females select sites for their webs based, in part, on the presence of con- or heterospecific webs, sensing both physical and chemical web cues. In bioassays, we offered female S. grossa a choice between an empty control frame and a frame bearing the web of a conspecific female or that of a female common house spider, Parasteatoda tepidarium CL Koch (Araneae: Theridiidae), recording (1) the time she spent, and (2) the time she spent inactive (a proxy for settling behaviour) on each frame. We also tested the effect of (1) silk micro- and macrostructure (wrapped-up silk or intact web, each semiochemical-deprived), (2) plastic webs, and (3) silk semiochemical extract on the responses of S. grossa females. Females settled on both con- and heterospecific webs and chose test stimuli based on their chemical and physical characteristics. Even plastic webs in cobweb-like arrangement readily prompted settling behaviour by females. Our results suggest that web architecture, rather than web silk, mediates settling responses by female S. grossa on pre-existing webs which may provide structural support for a new web and indicate habitat suitability. DOI
221. Peach, DAH; Almond, M; Gries, R; Gries, G. (2019) Lemongrass and Cinnamon Bark: Plant Essential Oil Blend as a Spatial Repellent for Mosquitoes in a Field Setting.J. Med. Entomol. 56: 1346-1352 Lemongrass and Cinnamon Bark: Plant Essential Oil Blend as a Spatial Repellent for Mosquitoes in a Field Setting
mosquito; plant essential oils; spatial repellent; synergism
Plant essential oils (EOs) have been considered as spatial repellents to help disrupt the pathogen transmission cycle of mosquitoes. Our objective was to assess spatial repellency effects of EOs on the tropical yellow fever mosquito, Aedes aegypti (L.) (Diptera: Culicidae) and on local mosquito populations in coastal British Columbia (Canada). In laboratory experiments using protocols of the World Health Organization, three of the solitary EOs tested proved repellent to Ae. aegypti: cinnamon bark, lemongrass, and rosemary. Binary combinations of select EOs enhanced the repellent effect of single EOs through synergistic interactions.The EO blend of geranium and peppermint lowered the RD50 (the dose required to obtain 50% repellency) of each solitary EO by >1,000-fold. Compared with binary EO blends, ternary EO blends were typically less repellent to mosquitoes, possibly due to a dilution effect of the most effective EO constituent(s) in the blend. In field experiments, the EO blend of lemongrass and cinnamon bark expressed spatial repellency towards the cool weather mosquito, Culiseta incidens (Thomson) (Diptera: Culicidae), even when this blend was disseminated from devices as much as 1 m away from a sentinel trap releasing attractive vertebrate host odorants and CO2. Deployment of EOs as spatial repellents in small outdoor gatherings could help protect humans from mosquito-borne diseases, particularly when this tactic is coupled with other tools of mosquito management. DOI PubMed
220. Peach, DAH; Gries, G. (2019) Mosquito phytophagy - sources exploited, ecological function, and evolutionary transition to haematophagy.Entomol. Exp. Appl.Mosquito phytophagy - sources exploited, ecological function, and evolutionary transition to haematophagy
mosquitoes; pollination; sensory ecology; plant-feeding; sugar-feeding; predation risk; microbes; monitoring; control; nectar thief
For a very long time, mosquitoes have been known or suspected to consume plant liquids. Recently eclosed mosquitoes cannot survive long without consuming sugary plant liquids that provide fuel for flight and enable blood-feeding and mating. Populations of even highly synanthropic mosquitoes may not be able to persist without phytophagy, even when vertebrate blood is readily available. Phytophagy is a key element of mosquito ecology, and understanding it is critical to combat mosquito-borne diseases. In this review, we summarize the current knowledge about mosquito phytophagy and outline future research needs. Specifically, we review the many plant-derived food sources mosquitoes exploit, study the pollination function of mosquitoes, highlight the predation risks of plant-foraging mosquitoes, investigate the role of microbes in the sugar-foraging ecology of mosquitoes, and shed light on the evolution of haematophagy. DOI
219. Peach, DAH; Gries, R; Young, N; Lakes, R; Galloway, E; Alamsetti, SK; Ko, E; Ly, A; Gries, G. (2019) Attraction of Female Aedes aegypti (L.) to Aphid Honeydew.Insects 10 Attraction of Female Aedes aegypti (L.) to Aphid Honeydew
Aedes aegypti; Acyrthosiphon pisum; Myzus persicae; Vicia faba; honeydew; honeydew odorants; mosquito sugar feeding; microbe-emitted odorants; mosquito olfaction
Plant sugar is an essential dietary constituent for mosquitoes, and hemipteran honeydew is one of the many forms of plant sugar that is important to mosquitoes. Many insects rely on volatile honeydew semiochemicals to locate aphids or honeydew itself. Mosquitoes exploit volatile semiochemicals to locate sources of plant sugar but their attraction to honeydew has not previously been investigated. Here, we report the attraction of female yellow fever mosquitoes, Aedes aegypti, to honeydew odorants from the green peach aphid, Myzus persicae, and the pea aphid, Acyrthosiphon pisum, feeding on fava bean, Vicia faba. We used solid phase micro-extraction and gas chromatography-mass spectrometry to collect and analyze headspace odorants from the honeydew of A. pisum feeding on V. faba. An eight-component synthetic blend of these odorants and synthetic odorant blends of crude and sterile honeydew that we prepared according to literature data all attracted female A. aegypti. The synthetic blend containing microbial odor constituents proved more effective than the blend without these constituents. Our study provides the first evidence for anemotactic attraction of mosquitoes to honeydew and demonstrates a role for microbe-derived odorants in the attraction of mosquitoes to essential plant sugar resources. DOI PubMed
218. Peach, DAH; Gries, R; Zhai, HM; Young, N; Gries, G. (2019) Multimodal floral cues guide mosquitoes to tansy inflorescences.Sci Rep 9 Multimodal floral cues guide mosquitoes to tansy inflorescences
Female mosquitoes exploit olfactory, CO2, visual, and thermal cues to locate vertebrate hosts. Male and female mosquitoes also consume floral nectar that provides essential energy for flight and survival. Heretofore, nectar-foraging mosquitoes were thought to be guided solely by floral odorants. Using common tansies, Tanacetum vulgare L., northern house mosquitoes, Culex pipiens L., and yellow fever mosquitoes, Aedes aegpyti (L.), we tested the hypothesis that the entire inflorescence Gestalt of olfactory, CO2 and visual cues is more attractive to mosquitoes than floral odorants alone. In laboratory experiments, we demonstrated that visual and olfactory inflorescence cues in combination attract more mosquitoes than olfactory cues alone. We established that tansies become net producers of CO2 after sunset, and that CO2 enhances the attractiveness of a floral blend comprising 20 synthetic odorants of tansy inflorescences. This blend included nine odorants found in human headspace. The "human-odorant-blend" attracted mosquitoes but was less effective than the entire 20-odorant floral blend. Our data support the hypothesis that the entire inflorescence Gestalt of olfactory, CO2 and visual cues is more attractive to mosquitoes than floral odorants alone. Overlapping cues between plants and vertebrates support the previously postulated concept that haematophagy of mosquitoes may have arisen from phytophagy. DOI PubMed
216. Peach, DAH; Ko, E; Blake, AJ; Gries, G. (2019) Ultraviolet inflorescence cues enhance attractiveness of inflorescence odour to Culex pipiens mosquitoes.PLoS One 14 Ultraviolet inflorescence cues enhance attractiveness of inflorescence odour to Culex pipiens mosquitoes
Inflorescence patterns of ultraviolet (UV) absorption and UV-reflection are attractive to many insect pollinators. To understand whether UV inflorescence cues affect the attraction of nectar-foraging mosquitoes, we worked with the common house mosquito, Culex pipiens and with two plant species exhibiting floral UV cues: the tansy, Tanacetum vulgare, and the common hawkweed Hieraciumm lachenalii. Electroretinograms revealed that Cx. pipiens eyes can sense UV wavelengths, with peak sensitivity at 335 nm. Behavioural bioassays divulged that UV inflorescence cues enhance the attractiveness of inflorescence odour. In the presence of natural floral odour, female Cx. pipiens were attracted to floral patterns of UV-absorption and UV-reflection but preferred uniformly UV-dark inflorescences. Moreover, Cx. pipiens females preferred UV-dark and black inflorescence models to UV-dark and yellow inflorescence models. With feathers and pelts of many avian and mammalian hosts also being UV-dark and dark-coloured, foraging Cx. pipiens females may respond to analogous visual cues when they seek nectar and vertebrate blood resources. DOI PubMed
215. Ren, WW; Gries, R; Kurita, KL; McCaughey, CS; Alamsetti, SK; Linington, RG; Gries, G; Britton, R. (2019) Isolation, Structure Elucidation, and Total Synthesis of Dolichovespulide, a Sesquiterpene from Dolichovespula Yellowjackets.J. Nat. Prod. 82: 2009-2012 Isolation, Structure Elucidation, and Total Synthesis of Dolichovespulide, a Sesquiterpene from Dolichovespula Yellowjackets
As part of an ongoing program to identify sex attractant pheromone components that mediate sexual communication in yellowjacket wasps, a novel sesquiterpene was isolated from body surface extracts of virgin bald-faced hornet queens, Dolichovespula maculata. The gross structure of this sesquiterpene was proposed through microscale spectroscopic analyses, and the configuration of the central olefin was subsequently confirmed by total synthesis. This new natural product (termed here dolichovespulide) represents an important addition to the relatively small number of terpenoids reported from the taxonomic insect family Vespidae. DOI PubMed
214. Renyard, A; Alamsetti, SK; Gries, R; Munoz, A; Gries, G. (2019) Identification of the Trail Pheromone of the Carpenter Ant Camponotus modoc.J. Chem. Ecol. 45: 901-913 Identification of the Trail Pheromone of the Carpenter Ant Camponotus modoc
Hymenoptera; Formicidae; Trail pheromone; Trail-following; Communication; Exocrine gland
Trail pheromones deposited by ants lead nestmates to food sources. Based on previous evidence that the trail pheromone of the carpenter ant Camponotus modoc originates from the hindgut, our objective in this study was to identify the key component(s) of the pheromone. We collected C. modoc colonies from conifer forests and maintained them in an outdoor enclosure near our laboratory for chemical analyses and behavioral experiments. In gas chromatographic-electroantennographic detection and gas chromatography-mass spectrometric analyses of worker ant hindgut extracts, we identified five candidate components: 2,4-dimethylhexanoic acid, 2,4-dimethyl-5-hexanolide, pentadecane, dodecanoic acid and 3,4-dihydro-8-hydroxy-3,5,7-trimethylisocoumarin. In a series of trail-following experiments, ants followed trails of synthetic 2,4-dimethyl-5-hexanolide, a blend of the five compounds, and hindgut extract over similar distances, indicating that the hexanolide accounted for the entire behavioral activity of the hindgut extract. The hexanolide not only mediated orientation of C. modoc foragers on trails, it also attracted them over distance, indicating a dual function. Further analyses and bioassays with racemic and stereoselectively synthesized hexanolides revealed that the ants produce, and respond to, the (2S,4R,5S)-stereoisomer. The same stereoisomer is a trail pheromone component in several Camponotus congeners, indicating significant overlap in their respective trail pheromone communication systems. DOI PubMed
213. Varner, E; Gries, R; Takacs, S; Fan, S; Gries, G. (2019) Identification and Field Testing of Volatile Components in the Sex Attractant Pheromone Blend of Female House Mice.J. Chem. Ecol. 45 Identification and Field Testing of Volatile Components in the Sex Attractant Pheromone Blend of Female House Mice
Female house mice; Mus musculus; Sex pheromone; Sex attractant; Volatiles
Recently, it was reported (i) that the sex pheromone blend of male house mice, Mus musculus, comprises not only volatile components (3,4-dehydro-exo-brevicomin; 2-sec-butyl-4,5-dihydrothiazole) but also a component of low volatility (the sex steroid testosterone), and (ii) that the sex steroids progesterone and estradiol are sex pheromone components of female house mice. Here we tested the hypothesis that the sex attractant pheromone blend of female mice, analogous to that of male mice, also comprises volatile pheromone components. Analyzing by GC-MS the head space volatiles of bedding soiled with urine and feces of laboratory-kept females and males revealed three candidate pheromone components (CPCs) that were adult female-specific: butyric acid, 2-methyl butyric acid and 4-heptanone. In a two-choice laboratory experiment, adult males spent significantly more time in the treatment chamber baited with both the synthetic steroids (progesterone, estradiol) and the synthetic CPCs than in the paired control chamber baited only with the synthetic steroids. In field experiments, trap boxes baited with both the CPCs and the steroids captured 6.7-times more adult males and 4.7-times more juvenile males than trap boxes baited with the steroids alone. Conversely, trap boxes baited with both the CPCs and the steroids captured 4.3-times more adult males and 2.7-fold fewer adult females than trap boxes baited with the CPCs alone. In combination, these data support the conclusion that butyric acid, 2-methyl butyric acid and 4-heptanone are part of the sex attractant pheromone of female house mice. With progesterone and estradiol being pheromone components of both female brown rats, Rattus norvegicus, and female house mice, these three volatile components could impart specificity to the sexual communication system of house mice, brown rats and possibly other rodent species. DOI PubMed
212. Babcock, T; Borden, J; Gries, R; Carroll, C; Moore, M; Gries, G. (2018) Lachancea thermotolerans, a Yeast Symbiont of Yellowjackets, Enhances Attraction of Three Yellowjacket Species (Hymenoptera: Vespidae) to Fruit Powder.Environ. Entomol. 47 Lachancea thermotolerans, a Yeast Symbiont of Yellowjackets, Enhances Attraction of Three Yellowjacket Species (Hymenoptera: Vespidae) to Fruit Powder
yellowjackets; Lachancea thermotolerans; semiochemical attractant; fruit bait; symbiotic yeast
Previously, we showed that the symbiotic yeast Lachancea thermotolerans (Filippov) (Saccharomycetales: Saccharomycetaceae) is attractive to its Vespula (Hymenoptera: Vespidae) yellowjacket hosts when grown on media supplemented with grape juice. We hypothesized that "Concerto': a commercial strain of this yeast, could be combined with fruit powder to form a shelf-stable bait for trapping yellowjackets. Using molecular techniques, we first confirmed that Concerto yeast is indeed the species L. thermotolerans. We then tested whether: 1) Concerto yeast produces volatiles similar to those produced by L. thermotolerans isolated from yellowjackets, 2) Concerto yeast enhances attraction of yellowjackets to fruit powder, 3) a Concerto yeast/fruit powder bait interacts synergistically with a yellowjacket semiochemical lure, and 4) a synthetic analog blend of Concerto-produced volatiles attracts yellowjackets. Using gas chromatography-mass spectrometry, we demonstrated that the chemical composition of Concerto-produced volatiles closely resembles that produced by a yellowjacket-isolated strain of L. thermotolerans. In field experiments, addition of Concerto to fruit powder doubled its attractiveness to yellowjackets. Addition of the Concerto/fruit powder bait to a heptyl butyrate-based wasp lure revealed a weak additive effect. A three-component synthetic analog blend of volatiles identified from the Concerto/fruit powder bait attracted Vespula pensylvanica (Saussure), but no other yellowjacket species. Our results suggest that commercial L. thermotolerans in combination with fruit powder could be used as a yellowjacket bait, and that addition of yeast-produced volatiles to a commercial wasp lure may improve its attractiveness to V. pensylvanica. Further research should determine why the synthetic volatile blend failed to attract Vespula species other than V. pensylvanica. DOI PubMed
211. Brodie, BS; Renyard, A; Gries, R; Zhai, HM; Ogilvie, S; Avery, J; Gries, G. (2018) Identification and field testing of floral odorants that attract the rove beetle Pelecomalium testaceum (Mannerheim) to skunk cabbage, Lysichiton americanus (L.).Arthropod-Plant Interact. 12 Identification and field testing of floral odorants that attract the rove beetle Pelecomalium testaceum (Mannerheim) to skunk cabbage, Lysichiton americanus (L.)
Lysichiton americanus; Araceae; Pelecomalium testaceum; Inflorescence semiochemicals; Pollination biology
Western skunk cabbage, Lysichiton americanus (Araceae), is pollinated mainly by the rove beetle Pelecomalium testaceum (Staphylinidae). Our objective was to determine the floral semiochemical(s) of L. americanus that attract(s) P. testaceum. Porapak Q headspace volatile extracts of L. americanus inflorescences were analyzed by gas chromatographic-electroantennographic detection (GC-EAD) and GC-mass spectrometry. In GC-EAD analyses, three floral odorants [(E)-4 nonene, (E)-5-undecene, indole] elicited consistent responses from the antennae of female P. testaceum. In field experiments, traps baited with a blend of these three components ("3-CB") captured significantly more P. testaceum than unbaited control traps. Traps baited with the 3-CB, the two hydrocarbons, or indole, each captured significantly more beetles than unbaited control traps, indicating redundancy in the semiochemical blend. Moreover, traps baited with indole captured significantly more beetles than traps baited with either the 3-CB, or the hydrocarbons, indicating that indole is a key floral attractant for P. testaceum. Many necrophilous and coprophilous insects respond to indole in search of carrion or feces, but P. testaceum has never been associated with these types of resources. Both electrophysiological and behavioral responses of P. testaceum to two hydrocarbon semiochemicals, which are not signature odorants of carrion or feces, may indicate that the beetles recognize the odor of L. americanus as an honest signal, seek and pollinate its inflorescences, and get rewarded with pollen and on-plant mating opportunities. DOI
210. Derstine, NT; Gries, R; Zhai, H; Jimenez, SI; Gries, G. (2018) Cuticular hydrocarbons determine sex, caste, and nest membership in each of four species of yellowjackets (Hymenoptera: Vespidae).Insect. Soc. 65 Cuticular hydrocarbons determine sex, caste, and nest membership in each of four species of yellowjackets (Hymenoptera: Vespidae)
Yellowjackets; Cuticular hydrocarbons; Sexual signaling; Sex; Caste; Nest membership; Linear discriminant analyses
Cuticular hydrocarbons (CHCs) of social insects have typically been studied for their roles in reproductive signaling (i.e., fertility) rather than sexual signaling (i.e., interest in mating), resulting in little information about CHCs of males and virgin females. This dearth of information applies particularly to social wasps. We tested the hypothesis that CHCs differentiate sex, caste, and nest membership in each of four yellowjacket species (baldfaced hornets, Dolichovespula maculata; southern yellowjackets, Vespula squamosa; western yellowjackets, V. pensylvanica; V. alascensis). Cold-euthanized queens (21), gynes (81), workers (125), and males (77) from 35 nests were extracted with pentane, and each of the resulting 304 extracts was analyzed by gas chromatography (GC) and GC-mass spectrometry to identify and quantify CHC constituents (aliphatic alkanes and alkenes; mono-, di-, and tri-methyl-branched alkanes). To determine whether caste and sex differ in CHC profiles of wasps, linear discriminant analyses were performed, using Z-transformed relative CHC peak areas as predictor variables and sex and caste, or nest, as grouping variables. When caste and sex were used as a grouping variable, plots of the first two discriminant functions revealed that wasps from each of the four species clustered into their respective groups (queens, gynes, workers, males), with significant differences in group centroids, as measured by Wilks' lambda. When nest was used as a grouping variable, plots of the first two discriminant functions revealed that workers from each of the four species and males from each of three species (insufficient sample size for V. pensylvanica) clustered according to nest. Diagnostic power calculations show greater inter-caste than inter-nest variation. Our data support the above hypothesis and inspire future studies to determine the definitive role(s) that gyne- and male-specific CHCs play in the context of sexual communication, from the perspective of both males and females. DOI
209. Fischer, A; Lee, Y; Stewart, J; Gries, G. (2018) Dodging sexual conflict?-Sub-adult females of a web-building spider stay cryptic to mate-seeking adult males.Ethology 124 Dodging sexual conflict?-Sub-adult females of a web-building spider stay cryptic to mate-seeking adult males
intersexual conflict; male cohabitation; sex pheromone; sexual selection; Steatoda grossa; sub-adult cue
Adult males of web-building spiders often cohabit the webs of sessile sub-adult (i.e. penultimate instar) females and mate with them as they moult to adults. Often, males accrue benefits from this cohabitation (kleptoparasitism, avoidance of cannibalism, potential polygamy), whereas sub-adult females may either accrue benefits or incur costs such as curtailed opportunity for mate choice or mate cannibalism. Working with the false black widow spider, Steatoda grossa, we tested the hypothesis that webs of sub-adult females, unlike those of virgin adult females, lack sex attractant pheromone that mate-seeking males could detect and exploit for mate location. We tested our hypothesis in laboratory experiments by presenting adult males with binary choices between different types of webs (e.g., webs of adult virgin females, sub-adult females or sub-adult males), and methanol extracts of these webs. Males spent more time on webs, or web extracts, of adult virgin females than on webs or web extracts of any other type. Most males (95%) also displayed courtship only on webs, or web extracts, of adult virgin females. Our data demonstrate apparent semiochemical crypsis of sub-adult females or their webs to mate-seeking adult males that seem to find sub-adult females by chance encounter. This crypsis is likely adaptive to sub-adult females that are in sexual conflict with adult males cohabiting their webs. DOI
208.Gries, R; Zhai, HM; Lewis, AR; Britton, R; Gries, G. (2018) Common bed bugs can biosynthesize pheromone components from amino acid precursors in human blood.Can. J. Chem. 96: 212-216 Common bed bugs can biosynthesize pheromone components from amino acid precursors in human blood
pheromone biosynthesis; L-methionine; histidine; histamine; dimethyl disulfide; dimethyl trisulfide
We have recently shown that the aggregation pheromone of the common bed bug, Cimex lectularius, comprises a six-component blend of dimethyl disulfide (DMDS), dimethyl trisulfide (DMTS), (E)-2-hexenal, (E)-2-octenal, 2-hexanone, and histamine. Here, we tested the hypothesis that bed bugs biosynthesize some pheromone components from amino acid precursors in human blood, namely DMDS and DMTS from L-methionine and histamine from histidine. We tested this hypothesis by (i) allowing bed bugs to feed on and metabolize sheep blood enriched with C-13-labelled histidine or H-2-labelled methionine, (ii) extracting bed bug feces (a source of the aggregation pheromone), and (iii) analyzing feces extracts by GC-MS, HPLC-MS and NMR spectroscopy. The analyses revealed that bed bugs converted H-2-methionine to H-2-DMDS and H-2-DMTS, and C-13-histidine to C-13-histamine. There is not enough histidine in human blood to account for the amount of histamine that bed bugs produce and excrete with their feces, and only a small proportion of the available C-13-histidine was converted to C-13-histamine in our study. Therefore, it is likely that bed bugs biosynthesize histamine, and possibly also DMDS and DMTS, primarily de novo. DOI
207. Holl, MV; Gries, G. (2018) Studying the "fly factor" phenomenon and its underlying mechanisms in house flies Musca domestica.Insect Sci. 25: 137-147 Studying the "fly factor" phenomenon and its underlying mechanisms in house flies Musca domestica
fly factor; foraging; metabolic output; microbes; Musca domestica; semiochemical attractants
The "fly factor" was first discovered > 60 years ago and describes the phenomenon that food currently or previously fed on by flies attracts more foraging flies than the same type and amount of food kept inaccessible to flies. Since then, there has been little progress made to understanding this phenomenon. Our objectives were (i) to demonstrate the existence of the fly factor in house flies, Musca domestica and (ii) to study underlying mechanisms that may cause or contribute to the fly factor. In 2-choice laboratory bioassays, we obtained unambiguous evidence for a fly factor phenomenon in house flies, in that we demonstrated that feeding flies are more attractive to foraging flies than are nonfeeding flies, and that fed-on food is more attractive to foraging flies than is "clean" food. Of the potential mechanisms (fly excreta, metabolic output parameters [elevated temperature, relative humidity, carbon dioxide]), causing the fly factor, fly feces, and regurgitate do attract foraging flies but none of the metabolic output parameters of feeding flies does. Even though feeding flies produce significantly more CO2 than nonfeeding flies, elevated levels of CO2 have no behavior-modifying effect on flies. Preferential attraction of house flies to fly feces and regurgitate indicates that the flies sense airborne semiochemicals emanating from these sources. Hypothesizing that these semiochemicals are microbe-produced, future studies will aim at isolating and mass producing these microbes to accumulate semiochemicals for identification. DOI
206. Pol, J; Gries, R; Gries, G. (2018) Rye bread and synthetic bread odorants - effective trap bait and lure for German cockroaches.Entomol. Exp. Appl. 166 Rye bread and synthetic bread odorants - effective trap bait and lure for German cockroaches
Blattella germanica; foraging; bread crust; bread crumb; water; beer; trap lure; trapping; Dictyoptera; Blattellidae; GC-MS; synthetic lure
Bread-in-beer and bread-in-water are prevalent home recipe trap baits for attracting German cockroaches (GCRs), Blattella germanica (L.) (Dictyoptera: Blattellidae), which are significant urban pests. Our objectives were to (1) test the attractiveness of these baits, (2) study the underlying factors of GCR attraction, and (3) determine whether a blend of synthetic bread odorants could replace bread in a trap lure. In large-arena laboratory experiments with laboratory-reared GCR males, traps baited with rye bread not only captured eightfold more males than unbaited control traps but also most males released into bioassay arenas. Neither beer nor water enhanced the attractiveness of bread. Bread crust as a bait was more effective than bread crumbs. As Porapak Q headspace volatile extracts of rye bread attracted GCRs, all rye bread odorants in extracts were identified by gas chromatography-mass spectrometry. Synthetic rye bread odorants and other known bread odorants were then assembled into a master blend. This master blend, and even partial blends lacking certain groups of organic volatiles such as aldehydes and ketones, proved very attractive to GCRs. We conclude that rye bread could be used as an effective bait in retainer traps or, laced with insecticide, as a food source in bait stations. A lure of synthetic bread odorants may eventually replace bread as bait, but the minimum number of essential odorants for that lure has yet to be determined. DOI
205. Ren, WW; Gries, R; McCaughey, C; Derstine, N; Alamsetti, SK; Kurita, KL; Tu, L; Linington, RG; Britton, R; Gries, G. (2018) Maculatic Acids-Sex Attractant Pheromone Components of Bald-Faced Hornets.Angew. Chem.-Int. Edit. 57 Maculatic Acids-Sex Attractant Pheromone Components of Bald-Faced Hornets
bald-faced hornets; gas chromatography; pheromones; yellowjackets
Yellowjackets in the genera Vespula and Dolichovespula are prevalent eusocial insects of great ecological and economic significance, but the chemical signals of their sexual communication systems have defied structural elucidation. Herein, we report the identification of sex attractant pheromone components of virgin bald-faced hornet queens (Dolichovespula maculata). We analyzed body surface extracts of queens by coupled gas chromatographic-electroantennographic detection (GC-EAD), isolated the compounds that elicited responses from male antennae by high-performance liquid chromatography (HPLC), and identified these components by GC mass spectrometry (MS), HPLC-MS, and NMR spectroscopy. In laboratory olfactometer experiments, synthetic (2Z,7E)-3,7-dimethyldeca-2,7-diendioic acid (termed here maculatic acidA) and (2Z,7E)-10-methoxy-3,7-dimethyldeca-10-oxo-deca-2,7-dienoic acid (termed here maculatic acid C) in binary combination significantly attracted bald-faced hornet males. These are the first sex attractant pheromone components identified in yellowjackets. DOI PubMed
204. Scott, C; Gerak, C; McCann, S; Gries, G. (2018) The role of silk in courtship and chemical communication of the false widow spider, Steatoda grossa (Araneae: Theridiidae).J. Ethol. 36 The role of silk in courtship and chemical communication of the false widow spider, Steatoda grossa (Araneae: Theridiidae)
Courtship behaviour; Mating; Sex pheromone; Web reduction; Spider silk
In spiders, sex pheromones are often associated with silk produced by females, and function in mate attraction, recognition, and evaluation. Silk-bound pheromones typically elicit courtship behaviour in web-building spiders. Here we (1) describe courtship interactions of Steatoda grossa males with virgin or mated females, and (2) show that silk and methanol extracts of silk produced by virgin females trigger courtship behaviour (silk production) by males, whereas silk of mated females does not. Our results indicate that (1) virgin females produce a silk-bound sex pheromone, (2) males discriminate between virgin and mated females based on silk cues, and (3) male silk likely functions in sexual communication. DOI
203. Takacs, S; Musso, AE; Gries, R; Rozenberg, E; Borden, JH; Brodie, B; Gries, G. (2018) New food baits for trapping house mice, black rats and brown rats.Appl. Anim. Behav. Sci. 200 New food baits for trapping house mice, black rats and brown rats
House mice; Brown rats; Black rats; Food baits; Field testing
We have recently developed new food baits (SFU Mouse Bait, SFU Rat Bait) for trapping granivorous house mice, Mus musculus, and black rats, Ramis rattus, and for trapping omnivorous brown rats, Rattus norvegicus. Both baits contain synthetic long-range volatile food attractants that represent favourite rodent foods. They draw foraging rodents to the baits where feeding stimulants induce feeding on them. Our objectives were to test the SFU Baits in comparison to three commercial mouse and rat baits, and peanut butter on trap captures of wild house mice, black rats and brown rats. In paired-trap experiments, traps baited with the SFU Mouse Bait captured (i) 6.6 times more mice than Provoke (R) Mouse (P < 0.001), (ii) 3.4 times more mice than Liphatech (R) (P < 0.05), (iii) 6.3 times more mice than Propest (R) (P = 0.001), and (iv) 3.4 times more mice than peanut butter (P < 0.05). Traps baited with the SFU Rat Bait captured (i) 5 times more brown rats than Provoke (R) Rat (P < 0.01), (ii) 3.5 times more brown rats than Liphatech (R) (P = 0.01), (iii) 12 times more brown rats than Propest (R) (P < 0.01), and (iv) 3.4 times more brown rats than peanut butter (P < 0.001). In a trapping location co-inhabited by both black and brown rats, traps baited with the SFU Mouse Bait captured 13 black rats (P < 0.01) and 5 brown rats, whereas traps baited with SFU Rat Bait captured 1 black rat and 25 brown rats (P < 0.001), revealing species specific differential attractiveness of these two baits. The superior performance of the SFU Mouse and Rat Baits is apparently due to the combination of their food attractant blends and their grain-based feeding stimulant matrix. When combined with novel rodent pheromone and sonic technologies, and possibly self-resetting traps, the SFU Baits have the potential to make rodent trapping as effective as rodent poisoning. DOI
202. Babcock, T; Gries, R; Borden, J; Palmero, L; Mattiacci, A; Masciocchi, M; Corley, J; Gries, G. (2017) Brewer's Yeast, Saccharomyces cerevisiae, Enhances Attraction of Two Invasive Yellowjackets (Hymenoptera: Vespidae) to Dried Fruit and Fruit Powder.J Insect Sci. 17 Brewer's Yeast, Saccharomyces cerevisiae, Enhances Attraction of Two Invasive Yellowjackets (Hymenoptera: Vespidae) to Dried Fruit and Fruit Powder
Vespula; Brewer's yeast; Saccharomyces; fermenting fruit; trap bait
The German yellowjacket, Vespula germanica F., and common yellowjacket, Vespula vulgaris L. (Hymenoptera: Vespidae), are pests of significant economic, environmental, and medical importance in many countries. There is a need for the development and improvement of attractive baits that can be deployed in traps to capture and kill these wasps in areas where they are a problem. Yellowjackets are known to feed on fermenting fruit, but this resource is seldom considered as a bait due to its ephemeral nature and its potential attractiveness to nontarget species. We analyzed the headspace volatiles of dried fruit and fruit powder baits with and without Brewer's yeast, Saccharomyces cerevisiae, using gas chromatography-mass spectrometry, and we field tested these baits for their attractiveness to yellowjackets in Argentina. The addition of yeast to dried fruit and fruit powder changed the volatile compositions, increasing the number of alcohols and acids and decreasing the number of aldehydes. Dried fruit and fruit powder baits on their own were hardly attractive to yellowjackets, but the addition of yeast improved their attractiveness by 9-to 50-fold and surpassed the attractiveness of a commercial heptyl butyrate-based wasp lure. We suggest that further research be done to test additional varieties and species of yeasts. A dried fruit or fruit powder bait in combination with yeast could become a useful tool in the management of yellowjackets. DOI
201. Derstine, NT; Ohler, B; Jimenez, SI; Landolt, P; Gries, G. (2017) Evidence for sex pheromones and inbreeding avoidance in select North American yellowjacket species.Entomol. Exp. Appl. 164: 35-44 Evidence for sex pheromones and inbreeding avoidance in select North American yellowjacket species
Dolichovespula; Vespula; Vespidae; Hymenoptera; social wasps; mate location; mate-finding behavior; field experiment; y-tube olfactometer; nestmate recognition
Little is known about the roles of sex pheromones in mate-finding behavior of social wasps (Vespidae). Working with the aerial yellowjacket, Dolichovespula arenaria (Fabricius), baldfaced hornet, Dolichovespula maculata (L.), western yellowjacket, Vespula pensylvanica (Saussure), southern yellowjacket, Vespula squamosa (Drury), and Vespula alascensis Packard, we tested the hypotheses (1) that gynes produce an airborne sex pheromone attractive to males, and (2) that males are more strongly attracted to non-sibling gynes based on olfactory cues. A field experiment provided the first definitive evidence that D. arenaria gynes attract males. Surprisingly, we did not find such evidence in similar field experiments for sexual attractiveness of gynes of V. squamosa, V. pensylvanica, V. alascensis, or D. maculata. In Y-tube olfactometer experiments with three of these species (D. arenaria, D. maculata, V. pensylvanica), only D. maculata gynes attracted males, provided they were non-siblings, implying an olfactory-basedmechanism of nestmate recognition and inbreeding avoidance. Lack of sex attraction responses for V. pensylvanica, V. alascensis, and V. squamosa in this study does not rule out pheromone-mediated sexual communication. Instead, it highlights the possibility that pheromonal signaling may be dependent on the presence of appropriate contextual cues. DOI
200. Eichorn, C; Hrabar, M; Van Ryn, EC; Brodie, BS; Blake, AJ; Gries, G. (2017) How flies are flirting on the fly.BMC Biology 15 How flies are flirting on the fly
Lucilia sericata; Mate location; Visual mate signals; Wing flashes; Flicker fusion frequency
Background: Flies have some of the most elaborate visual systems in the Insecta, often featuring large, sexually dimorphic eyes with specialized "bright zones" that may have a functional role during mate-seeking behavior. The fast visual system of flies is considered to be an adaptation in support of their advanced flight abilities. Here, we show that the immense processing speed of the flies' photoreceptors plays a crucial role in mate recognition. Results: Video-recording wing movements of abdomen-mounted common green bottle flies, Lucilia sericata, under direct light at 15,000 frames per second revealed that wing movements produce a single, reflected light flash per wing beat. Such light flashes were not evident when we video-recorded wing movements under diffuse light. Males of L. sericata are strongly attracted to wing flash frequencies of 178 Hz, which are characteristic of free-flying young females (prospective mates), significantly more than to 212, 235, or 266 Hz, characteristic of young males, old females, and old males, respectively. In the absence of phenotypic traits of female flies, and when given a choice between light emitting diodes that emitted either constant light or light pulsed at a frequency of 110, 178, 250, or 290 Hz, males show a strong preference for the 178-Hz pulsed light, which most closely approximates the wing beat frequency of prospective mates. Conclusions: We describe a previously unrecognized visual mate recognition system in L. sericata. The system depends upon the sex- and age-specific frequencies of light flashes reflecting off moving wings, and the ability of male flies to distinguish between the frequency of light flashes produced by rival males and prospective mates. Our findings imply that insect photoreceptors with fast processing speed may not only support agile flight with advanced maneuverability but may also play a supreme role in mate recognition. The low mating propensity of L. sericata males on cloudy days, when light flashes from the wings of flying females are absent, seems to indicate that these flies synchronize sexual communication with environmental conditions that optimize the conspicuousness of their communication signals, as predicted by sensory drive theory. DOI
199. Hayden, ME; Lambinet, V; Gomis, S; Gries, G. (2017) Evaluation of magnetometry data acquired from elongated samples.Rev. Sci. Instrum. 88 Evaluation of magnetometry data acquired from elongated samples
We document and validate an analytic expression for the flux integral characterizing the response (or sensitivity) of a magnetometer equipped with second-order axial gradiometer coils to long, thin, uniformly magnetized samples. We then demonstrate an application inspired by this analysis, in which magnetometric sensitivity to weak magnetic signatures is readily and appreciably enhanced by increasing the sample volume (and hence the quantity of analyte) well beyond conventional limits. Published by AIP Publishing. DOI
198. Jimenez, SI; Carroll, C; Babcock, T; Derstine, N; Hadwin, A; Moore, M; Gries, G. (2017) Yeasts Harbored by Vespine Wasps in the Pacific Northwest.Environmental Entomology 46: 217-225 Yeasts Harbored by Vespine Wasps in the Pacific Northwest
Lachancea; Hanseniaspora; vespine wasp; yeast-wasp interaction
The ecological role of social wasps has been extensively studied, but little is known about symbiotic relationships of these wasps with microbes. Recently, it was shown that vespid wasps in Europe carry yeasts, predominantly Saccharomyces cerevisiae, in their gastrointestinal (GI) tract. Interestingly, this niche allowed for sexual recombination of yeasts to occur and the formation of novel hybrid species. Our goals were 1) to survey the GI tract of eusocial wasps in the Pacific Northwest for the presence of yeasts and 2) to compare the diversity of such yeasts to that described for wasps in Europe. The GI tracts of 19 individual wasps from five species were plated, and 27 yeast-like colonies were identified to the species level. Yeasts in the genera Lachancea and Hanseniaspora each comprised similar to 30% of the isolates; similar to 25% were identified as Metschnikowia spp., with the remaining 10% belonging to Rhodotorula. Four bacterial isolates were identified as Escherichia coli, Enterococcus faecalis, and two isolates of Stenotrophomonas maltophilia. Yeasts were present at all life stages of the wasps except for two unfed gynes of Dolichovespula maculata (L.) that contained only bacteria. The presence of a particular yeast species was not correlated with any wasp species. Furthermore, S. cerevisiae was not found in any wasp species. This highlights an interesting difference in the life cycle of both S. cerevisiae and wasps in Europe and the Pacific Northwest, and prompts further studies on the interactions of these microbes with their host wasps. DOI
197. Lambinet, V; Hayden, ME; Reid, C; Gries, G. (2017) Honey bees possess a polarity-sensitive magnetoreceptor.J. Comp. Physiol. A -Neuroethol. Sens. Neural Behav. Physiol. 203: 1029-1036 Honey bees possess a polarity-sensitive magnetoreceptor
Honey bees; Apis mellifera; Magnetoreception; Inclination compass; Polarity compass
Honey bees, Apis mellifera, exploit the geomagnetic field for orientation during foraging and for alignment of their combs within hives. We tested the hypothesis that honey bees sense the polarity of magnetic fields. We created an engineered magnetic anomaly in which the magnetic field generally either converged toward a sugar reward in a watch glass, or away from it. After bees in behavioral field studies had learned to associate this anomaly with a sugar water reward, we subjected them to two experiments performed in random order. In both experiments, we presented bees with two identical sugar water rewards, one of which was randomly marked by a magnetic field anomaly. During the control experiment, the polarity of the magnetic field anomaly was maintained the same as it was during the training session. During the treatment experiment, it was reversed. We predicted that bees would not respond to the altered anomaly if they were sensitive to the polarity of the magnetic field. Our findings that bees continued to respond to the magnetic anomaly when its polarity was in its unaltered state, but did not respond to it when its polarity was reversed, support the hypothesis that honey bees possess a polarity-sensitive magnetoreceptor. DOI
196. Lambinet, V; Hayden, ME; Reigl, K; Gomis, S; Gries, G. (2017) Linking magnetite in the abdomen of honey bees to a magnetoreceptive function.Proceedings of the Royal Society B-Biological Sciences 284 Linking magnetite in the abdomen of honey bees to a magnetoreceptive function
honey bees; magnetoreception; magnetic sense; magnetite; hysteresis loop; magnetic remanence
Previous studies of magnetoreception in honey bees, Apis mellifera, focused on the identification of magnetic material, its formation, the location of the receptor and potential underlying sensory mechanisms, but never directly linked magnetic material to a magnetoreceptive function. In our study, we demonstrate that ferromagnetic material consistent with magnetite plays an integral role in the bees' magnetoreceptor. Subjecting lyophilized and pelletized bee tagmata to analyses by a superconducting quantum interference device generated a distinct hysteresis loop for the abdomen but not for the thorax or the head of bees, indicating the presence of ferromagnetic material in the bee abdomen. Magnetic remanence of abdomen pellets produced from bees that were, or were not, exposed to the 2.2-kOe field of a magnet while alive differed, indicating that magnet exposure altered the magnetization of this magnetite in live bees. In behavioural two-choice field experiments, bees briefly exposed to the same magnet, but not sham-treated control bees, failed to sense a custom-generated magnetic anomaly, indicating that magnet exposure had rendered the bees' magnetoreceptor dysfunctional. Our data support the conclusion that honey bees possess a magnetite-based magnetoreceptor located in the abdomen. DOI
195. Musso, AE; Gries, R; Zhai, HM; Takacs, S; Gries, G. (2017) Effect of Male House Mouse Pheromone Components on Behavioral Responses of Mice in Laboratory and Field Experiments.Journal of Chemical Ecology 43: 215-224 Effect of Male House Mouse Pheromone Components on Behavioral Responses of Mice in Laboratory and Field Experiments
House mice; Mus musculus; Sex attractant pheromone components; Field experiment; Mouse control
Urine of male house mice, Mus musculus, is known to have primer pheromone effects on the reproductive physiology of female mice. Urine-mediated releaser pheromone effects that trigger certain behavioral responses are much less understood, and no field studies have investigated whether urine deposits by male or female mice, or synthetic mouse pheromone, increase trap captures of mice. In field experiments, we baited traps with bedding soiled with urine and feces of caged female or male mice, and recorded captures of mice in these and in control traps containing clean bedding. Traps baited with female bedding preferentially captured adult males, whereas traps baited with male bedding preferentially captured juvenile and adult females, indicating the presence of male-and female-specific sex pheromones in soiled bedding. Analyses of headspace volatiles emanating from soiled bedding by gas chromatography/mass spectrometry revealed that 3,4-dehydro-exo-brevicomin (DEB) was seven times more prevalent in male bedding and that 2-sec-butyl-4,5-dihydrothiazole (DHT) was male-specific. In a follow-up field experiment, traps baited with DEB and DHT captured 4 times more female mice than corresponding control traps, thus indicating that DEB and DHT are sex attractant pheromone components of house mouse males. Our study provides impetus to identify the sex attractant pheromone of female mice, and to develop synthetic mouse pheromone as a lure to enhance the efficacy of trapping programs for mouse control. DOI
194. Pol, JC; Jimenez, SI; Gries, G. (2017) New Food Baits for Trapping German Cockroaches, Blattella germanica (L.) (Dictyoptera: Blattellidae).J. Econ. Entomol. 110: 2518-2526 New Food Baits for Trapping German Cockroaches, Blattella germanica (L.) (Dictyoptera: Blattellidae)
German cockroach; dry malt extract; Brewer's yeast; attraction; commercial cockroach bait
German cockroaches (GCRs), Blattella germanica (L.) (Dictyoptera: Blattellidae), are attracted to those beer semiochemicals (e.g., ethanol) that formerly living and active yeasts have produced or otherwise formed in the brewing process. We predicted that an earlier step in the production of beer, where yeasts actively metabolize the sugar in malted barley powder (dry malt extract [DME]), is very attractive to GCRs. In laboratory experiments, a 3-component composition (3CC) comprising DME, water, and Brewer's yeast strongly attracted GCR nymphs, females, and males. Both Brewers' yeast and ` spoilage organisms' in the DME or water seem to add to the attractiveness of the 3CC, but there is no additive or synergistic effect between them. The 3CC becomes optimally attractive to GCRs after 12 h of fermentation and stays that attractive for at least 120 h. In field trapping experiments, the 3CC and-unexpectedly-also the DME each proved as effective for attracting and capturing GCRs as a commercial cockroach bait (Combat Roach Gel). Future studies will investigate lethal biocontrol agents that can be added to the 3CC, or the DME, and will explore the efficacy of such lethal baits for GCR control. DOI
193. Riesch, R; Muschick, M; Lindtke, D; Villoutreix, R; Comeault, AA; Farkas, TE; Lucek, K; Hellen, E; Soria-Carrasco, V; Dennis, SR; de Carvalho, CF; Safran, RJ; Sandoval, CP; Feder, J; Gries, R; Crespi, BJ; Gries, G; Gompert, Z; Nosil, P. (2017) Transitions between phases of genomic differentiation during stick-insect speciation.Nature Ecology & Evolution 1 Transitions between phases of genomic differentiation during stick-insect speciation
Speciation can involve a transition from a few genetic loci that are resistant to gene flow to genome-wide differentiation. However, only limited data exist concerning this transition and the factors promoting it. Here, we study phases of speciation using data from >100 populations of 11 species of Timema stick insects. Consistent with early phases of genie speciation, adaptive colour-pattern loci reside in localized genetic regions of accentuated differentiation between populations experiencing gene flow. Transitions to genome-wide differentiation are also observed with gene flow, in association with differentiation in polygenic chemical traits affecting mate choice. Thus, intermediate phases of speciation are associated with genome-wide differentiation and mate choice, but not growth of a few genomic islands. We also find a gap in genomic differentiation between sympatric taxa that still exchange genes and those that do not, highlighting the association between differentiation and complete reproductive isolation. Our results suggest that substantial progress towards speciation may involve the alignment of multi-faceted aspects of differentiation. DOI
192. Takacs, S; Gries, R; Gries, G. (2017) Sex Hormones Function as Sex Attractant Pheromones in House Mice and Brown Rats.ChemBioChem 18: 1391-1395 Sex Hormones Function as Sex Attractant Pheromones in House Mice and Brown Rats
brown rats; field testing; hormones; house mice; pheromones; rodent control
Sex hormones of mammals control the expression of sexual characteristics and bodily functions. The male hormone testosterone and the female hormones progesterone and estradiol are known to occur in urine markings of mice. Here, we show that all three hormones are also present in urine of brown rats, and that they are effective sexual communication signals (pheromones) that elicit attraction behavior of prospective mates in both brown rats and house mice. When added as lures to trap boxes in field experiments, synthetic testosterone, for example, increased captures of adult female mice 15-fold, and a blend of progesterone and estradiol increased captures of male mice eightfold and male rats 13-fold. Remarkably, these hormones increased captures even though the food-and pheromone-based baits to which they were added had previously been shown to be superior to current commercial rodent attractants. We predict that these sex hormones will function as sex attractant pheromones in diverse taxa. DOI
191. Vibert, S; Salomon, M; Scott, C; Blackburn, GS; Gries, G. (2017) Life-history data for the funnel weavers Eratigena agrestis and Eratigena atrica (Araneae: Agelenidae) in the Pacific Northwest of North America.Canadian Entomologist 149: 345-356 Life-history data for the funnel weavers Eratigena agrestis and Eratigena atrica (Araneae: Agelenidae) in the Pacific Northwest of North America
The life history of the funnel weaver Eratigena agrestis (Walckenaer) (Araneae: Agelenidae) is not well studied despite its widespread occurrence in Europe and its establishment and spread in the Pacific Northwest of North America since its introduction in the early 20th century. We report phenology and life-history data for E. agrestis and another co-occurring funnel weaver, Eratigena atrica (Koch), in two study sites in British Columbia, Canada. The most notable difference in phenology between the two Eratigena species was the timing of emergence: E. atrica spiderlings emerge in the fall whereas E. agrestis spiderlings emerge in the spring. Surprisingly, the contrasting densities of E. atrica in the two study sites and the presence of the western black widow spider, Latrodectus hesperus Chamberlin and Ivie (Araneae: Theridiidae), in one study site had little effect on the life history of E. agrestis. This unexpected finding may be explained by (i) low overall competition pressure in the study habitats, (ii) conspecifics and heterospecifics exerting equivalent competition or predation pressures; and/or (iii) aggregations of heterospecifics providing benefits that offset costs associated with any competition. DOI
190. Foster, AJ; Aloni, R; Fidanza, M; Gries, R; Gries, G; Mattsson, J. (2016) Foliar phase changes are coupled with changes in storage and biochemistry of monoterpenoids in western redcedar (Thuja plicata).Trees-Structure and Function 30: 1361-1375 Foliar phase changes are coupled with changes in storage and biochemistry of monoterpenoids in western redcedar (Thuja plicata)
Western redcedar; Thuja plicata; Monoterpenes; Ontogeny; Metamorphic heteroblasty; Resin ducts; Resin glands; alpha-Thujone; Herbivory
The monoterpenoid content of Thuja plicata needles and scales differs both quantitatively and qualitatively. Resin storage structures are associated with anatomical modifications that suggest facilitated exit of monoterpenoids. Western redcedar (Thuja plicata) is a highly valued source of lumber. T. plicata trees planted in reforestations efforts are often heavily damaged by extensive ungulate browsing. Research has shown that high foliar content of monoterpenoids deters browsing, providing an avenue for resistance selection in young plants. T. plicata foliage undergoes, however, extensive phase changes during early growth. Currently it is unknown whether the anatomical basis of monoterpenoid storage and release, and the content and composition of stored monoterpenoids, also change at the same time. Here, we studied these aspects of T. plicata seedling biology. Cotyledons lack storage structures for terpenoids. Needles contain a single longitudinal terpenoid duct with (+)-sabinene and (-)-alpha-pinene as prevalent monoterpenoids. In contrast, scales contain enclosed resin glands and have a monoterpenoid profile that is markedly different from needles, with alpha-thujone as the most prevalent monoterpenoid and no detectable levels of (-)-alpha-pinene. Both ducts and glands are close to the epidermis and vascular tissues, frequently companioned by gaps in the sub-epidermal fiber layer, suggesting paths of facilitated diffusion of monoterpenoids out of tissues. We conclude that foliar phase changes are coupled with equally significant changes in resin storage structure anatomy, monoterpenoid levels and composition. Our findings provide a framework for reproducible sampling and selection not only for high levels of monoterpenoids but also for anatomical markers that may affect release of these compounds. DOI
189. Jimenez, SI; Gries, R; Zhai, HM; Derstine, N; McCann, S; Gries, G. (2016) Evidence for a Nest Defense Pheromone in Bald-Faced Hornets, Dolichovespula Maculata, and Identification of Components.Journal of Chemical Ecology 42: 414-424 Evidence for a Nest Defense Pheromone in Bald-Faced Hornets, Dolichovespula Maculata, and Identification of Components
Dolichovespula maculata; Bald-faced hornet; Alarm pheromone; Vespidae; Nest defense
In eusocial insects like Bald-faced hornets, Dolichovespula maculata, nest defense is essential because nests contain a large number of protein-rich larvae and pupae, and thus are attractive to nest predators. Our objectives were to investigate whether D. maculata exhibit pheromone-mediated nest defense, and to identify and field test any pheromone components. We tested for pheromone-mediated nest defense behavior of D. maculata by placing a paired box-apparatus near the entrance of D. maculata nests, and treating both boxes with a solvent control, or one of the two boxes with a solvent control and the other with either venom sac extract, the putative source of nest defense pheromone, or synthetic pheromone. The sound impulses caused by nest mates attempting to sting or strike the boxes were recorded for 3 min. Compared to the double-control treatment, the number of strikes increased 27-fold when one of the two boxes was treated with venom sac extract, providing evidence for an alarm response. The box treated with venom sac extract also induced a significantly greater proportion of strikes than the corresponding control box, providing evidence for a target-oriented response. Analyzing venom sac extract by gas chromatographic-electroantennographic detection (GC-EAD) and GC-mass spectrometry resulted in the identification of seven candidate pheromone components: (a) dimethylaminoethanol, (b) dimethylamino ethyl acetate, (c) 2,5-dimethylpyrazine, (d) N-3-methylbutylacetamide, (e) 2-heptadecanone, (f) (Z)-8-heptadecen-2-one, and (g) (Z)-10-nonadecen-2-one. Testing in paired-box bioassays blends of the nitrogen-containing volatile components a-d, the less volatile ketones e-g, or both (a-g), indicated that a-d primarily have an alarm function. The ketones e-g, in contrast, induced target-oriented responses, possibly marking the box, or potential nest predators, for guided and concerted attacks, or enhancing the alarm-inducing effect of the volatile pheromone components, as shown in honey bees. Comparing the behavioral effects of venom sac extract, blends a-d, e-g, and a-g, venom sac extract was most effective in triggering the full complement of alarm and target-oriented responses. These comparisons further suggested that a component is missing in the group of components that triggers the alarm rather than the target-oriented response. DOI
188. Peach, DAH; Gries, G. (2016) Nectar thieves or invited pollinators? A case study of tansy flowers and common house mosquitoes.Arthropod-Plant Interactions 10: 497-506 Nectar thieves or invited pollinators? A case study of tansy flowers and common house mosquitoes
Pollination; Culex pipiens; Tanacetum vulgare; Asteraceae; Mosquitoes
Mosquitoes are generally considered nectar thieves that do not contribute to the pollination of the flowers they visit. Here we tested the hypothesis that the common house mosquito, Culex pipiens, contributes to the pollination of tansies, Tanacetum vulgare, and possibly the pollination of other members of the Asteraceae (Achillea millefolium, Leucanthemum vulgare, Solidago canadensis). To test this hypothesis, we (1) field-collected mosquitoes probing inflorescences of T. vulgare, A. millefolium, and L. vulgare, and recorded the number and distribution of pollen grains on their bodies, (2) exposed laboratory-reared Cx. pipiens to inflorescences of T. vulgare, A. millefolium, and S. canadensis, and (3) ran pollination experiments with Cx. pipiens and T. vulgare in a greenhouse. We found (1) that 41 of 164 field-collected Cx. pipiens carried pollen, (2) that 48, 34, and 34 % of Cx. pipiens accumulated pollen from T. vulgare, A. millefolium, and S. canadensis, respectively, during floral visits of greenhouse-grown specimens, and (3) that cross-pollination by Cx. pipiens resulted in significant seed set of T. vulgare in pollination experiments. Based on our observations that Cx. pipiens are frequent floral visitors and are able to carry pollen and to induce seed set in T. vulgare, it is clear that Cx. pipiens plays a role in the pollination of T. vulgare, and possibly other members of the Asteraceae. DOI
187. Takacs, S; Gries, R; Zhai, HM; Gries, G. (2016) The Sex Attractant Pheromone of Male Brown Rats: Identification and Field Experiment.Angewandte Chemie-International Edition 55: 6062-6066 The Sex Attractant Pheromone of Male Brown Rats: Identification and Field Experiment
brown rats; field experiments; ketones; pheromones
Trapping brown rats is challenging because they avoid newly placed traps in their habitat. Herein, we report the identification of the sex pheromone produced by male brown rats and its effect on trap captures of wild female brown rats. Collecting urine- and feces-soiled bedding material of laboratory-kept rats and comparing the soiled-bedding odorants of juvenile and adult males, as well as of adult males and females, we found nine compounds that were specific to, or most prevalent in, the odor profiles of sexually mature adult males. When we added a synthetic blend of six of these compounds (2-heptanone, 4-heptanone, 3-ethyl-2-heptanone, 2-octanone, 2-nonanone, 4-nonanone) to one of two paired food-baited trap boxes, these boxes attracted significantly more laboratory-strain female rats in laboratory experiments, and captured ten times more wild female rats in a field experiment than the corresponding control boxes. Our data show that the pheromone facilitates captures of wild female brown rats. DOI
186. Takacs, S; Kowalski, P; Gries, G. (2016) Natural and synthetic vocalizations of brown rat pups, Rattus norvegicus, enhance attractiveness of bait boxes in laboratory and field experiments.Pest Management Science 72: 1873-1882 Natural and synthetic vocalizations of brown rat pups, Rattus norvegicus, enhance attractiveness of bait boxes in laboratory and field experiments
brown rats; Rattus norvegicus; neophobia; pup vocalizations; phonotactic and arrestment responses; sonic trap bait; trapping efficacy
BACKGROUNDRats are often neophobic and thus do not readily enter trap boxes which are mandated in rodent management to help reduce the risk of accidental poisoning or capture of non-target animals. Working with brown rats, Rattus norvegicus, as a model species, our overall objective was to test whether sound cues from pups could be developed as a means to enhance captures of rats in trap boxes. RESULTSRecording vocalizations from three-day-old pups after removal from their natal nest with both sonic and ultrasonic microphones revealed frequency components in the sonic range (1.8-7.5 kHz) and ultrasonic range (18-24 kHz, 33-55 kHz, 60-96 kHz). In two-choice laboratory bioassays, playback recordings of these vocalizations induced significant phonotactic and arrestment responses by juvenile, subadult and adult female and male rats. The effectiveness of engineered synthetic' rat pup sounds was dependent upon their frequency components, sound durations and the sound delivery system. Unlike other speakers, a piezoelectric transducer emitting sound bursts of 21 kHz with a 63-KHz harmonic, and persisting for 20-300 ms, proved highly effective in attracting and arresting adult female rats. In a field experiment, a battery-powered electronic device fitted with a piezoelectric transducer and driven by an algorithm that randomly generated sound cues resembling those recorded from rat pups and varying in fundamental frequency (19-23 kHz), duration (20-300 ms) and intermittent silence (300-5000 ms) significantly enhanced captures of rats in trap boxes baited with a food lure and soiled bedding material of adult female rats. CONCLUSIONOur study provides proof of concept that rat-specific sound cues or signals can be effectively reproduced and deployed as a means to enhance capture of wild rats. (c) 2016 Society of Chemical Industry DOI
185. Vibert, S; Scott, C; Gries, G. (2016) Vibration transmission through sheet webs of hobo spiders (Eratigena agrestis) and tangle webs of western black widow spiders (Latrodectus hesperus).Journal of Comparative Physiology A-Neuroethology Sensory Neural and Behavioral Physiology 202: 749-758 Vibration transmission through sheet webs of hobo spiders (Eratigena agrestis) and tangle webs of western black widow spiders (Latrodectus hesperus)
Signal transmission; Acoustic communication; Spider webs; Araneae
Web-building spiders construct their own vibratory signaling environments. Web architecture should affect signal design, and vice versa, such that vibratory signals are transmitted with a minimum of attenuation and degradation. However, the web is the medium through which a spider senses both vibratory signals from courting males and cues produced by captured prey. Moreover, webs function not only in vibration transmission, but also in defense from predators and the elements. These multiple functions may impose conflicting selection pressures on web design. We investigated vibration transmission efficiency and accuracy through two web types with contrasting architectures: sheet webs of Eratigena agrestis (Agelenidae) and tangle webs of Latrodectus hesperus (Theridiidae). We measured vibration transmission efficiencies by playing frequency sweeps through webs with a piezoelectric vibrator and a loudspeaker, recording the resulting web vibrations at several locations on each web using a laser Doppler vibrometer. Transmission efficiencies through both web types were highly variable, with within-web variation greater than among-web variation. There was little difference in transmission efficiencies of longitudinal and transverse vibrations. The inconsistent transmission of specific frequencies through webs suggests that parameters other than frequency are most important in allowing these spiders to distinguish between vibrations of prey and courting males. DOI
184. Zhai, HM; Hrabar, M; Gries, R; Gries, G; Britton, R. (2016) Total Synthesis, Stereochemical Assignment, and Field-Testing of the Sex Pheromone of the Strepsipteran Xenos peckii.Chem.-Eur. J. 22: 6190-6193 Total Synthesis, Stereochemical Assignment, and Field-Testing of the Sex Pheromone of the Strepsipteran Xenos peckii
insect pheromone; natural products; stereochemical assignment; Suzuki-Miyaura; Xenos peckii
The sex pheromone of the endoparasitoid insect Xenos peckii (Strepsiptera: Xenidae) was recently identified as (7E, 11E)-3,5,9,11-tetramethyl-7,11-tridecadienal. Herein we report the asymmetric synthesis of three candidate stereostructures for this pheromone using a synthetic strategy that relies on an sp(3)-sp(2) Suzuki-Miyaura coupling to construct the correctly configured C7-alkene function. Comparison of H-1 NMR spectra derived from the candidate stereostructures to that of the natural sex pheromone indicated a relative configuration of (3R*, 5S*, 9R*). Chiral gas chromatographic (GC) analyses of these compounds supported an assignment of (3R, 5S, 9R) for the natural product. Furthermore, in a 16-replicate field experiment, traps baited with the synthetic (3R, 5S, 9R)-enantiomer alone or in combination with the (3S, 5R, 9S)-enantiomer captured 23 and 18 X. peckii males, respectively (mean +/- SE: 1.4 +/- 0.33 and 1.1 +/- 0.39), whereas traps baited with the synthetic (3S, 5R, 9S)-enantiomer or a solvent control yielded no captures of males. These strong field trapping data, in combination with spectroscopic and chiral GC data, unambiguously demonstrate that (3R, 5S, 9R, 7E, 11E)-3,5,9,11-tetramethyl-7,11-tridecadienal is the X. peckii sex pheromone. DOI PubMed
183. Brodie, BS; Smith, MA; Lawrence, J; Gries, G. (2015) Effects of Floral Scent, Color and Pollen on Foraging Decisions and Oocyte Development of Common Green Bottle Flies.PLoS One 10 Effects of Floral Scent, Color and Pollen on Foraging Decisions and Oocyte Development of Common Green Bottle Flies
The common green bottle fly Lucilia sericata (Meigen) and other filth flies frequently visit pollen-rich composite flowers such as the Oxeye daisy, Leucanthemum vulgare Lam. In laboratory experiments with L. sericata, we investigated the effect of generic floral scent and color cues, and of Oxeye daisy-specific cues, on foraging decisions by recently eclosed flies. We also tested the effect of a floral pollen diet with 0-35% moisture content on the ability of females to mature their oocytes. Our data indicate that (1) young flies in the presence of generic floral scent respond more strongly to a uniformly yellow cue than to any other uniform color cue (green, white, black, blue, red) except for ultraviolet (UV); (2) the floral scent of Oxeye daisies enhances the attractiveness of a yellow cue; and (3) moisture-rich pollen provides nutrients that facilitate ovary maturation of flies. With evidence that L. sericata exploits floral cues during foraging, and that pollen can be an alternate protein source to animal feces and carrion, Pollen apparently plays a major role in the foraging ecology of L. sericata and possibly other filth flies. These flies, in turn, may play a significant role as pollinators, as supported by a recently published study. DOI
182. Brodie, BS; Wong, WHL; VanLaerhoven, S; Gries, G. (2015) Is aggregated oviposition by the blow flies Lucilia sericata and Phormia regina (Diptera: Calliphoridae) really pheromone-mediated?Insect Science 22: 651-660 Is aggregated oviposition by the blow flies Lucilia sericata and Phormia regina (Diptera: Calliphoridae) really pheromone-mediated?
blow flies; carrion; egg-laying site; pheromone; saliva; semiochemical
When female blow flies Lucilia sericata and Phormia regina (Diptera: Calliphoridae) oviposit in aggregations on carrion, even-aged larval offspring reportedly develop faster, and fewer are parasitized or preyed upon. The benefits of aggregated oviposition equally affect con- and heterospecific larvae sharing a resource. The benefits imply that female blow flies engage in coordinated, pheromone-mediated oviposition behavior. Yet, repeated attempts to identify oviposition pheromones have failed invoking doubt that they exist. Simply by regurgitating and feeding on carrion, flies may produce attractive semiochemicals. If flies were to aggregate in response to feeding flies rather than ovipositing flies, then the semiochemical cue(s) may be associated with the salivary gland. Working with L. sericata and P. regina and using liver as a surrogate oviposition medium, we test the hypotheses, and present data in their support, that (i) gravid or nongravid females ovipositing and/or feeding on liver enhance its attractiveness to gravid and nongravid females; (ii) females respond to semiochemicals from feeding heterospecific females; (iii) females respond equally well to semiochemicals from feeding con- and heterospecific females; (iv) macerated head tissues of females applied to liver enhance its attractiveness; and (v) females in direct contact with and feeding on liver, but not when next to yet physically separated from liver, enhance attraction of flies. We conclude that oviposition site-seeking females do not respond to an oviposition pheromone. Instead, they appear to coopt semiochemicals associated with feeding flies as resource indicators, taking chances that resources are suitable for oviposition, and that ovipositing flies are present. DOI
181.Gries, R; Britton, R; Holmes, M; Zhai, HM; Draper, J; Gries, G. (2015) Bed Bug Aggregation Pheromone Finally Identified.Angewandte Chemie-International Edition 54: 1135-1138 Bed Bug Aggregation Pheromone Finally Identified
aggregation pheromone; bed bugs; histamine; semiochemicals
Bed bugs have become a global epidemic and current detection tools are poorly suited for routine surveillance. Despite intense research on bed bug aggregation behavior and the aggregation pheromone, which could be used as a chemical lure, the complete composition of this pheromone has thus far proven elusive. Here, we report that the bed bug aggregation pheromone comprises five volatile components (dimethyl disulfide, dimethyl trisulfide, (E)-2-hexenal, (E)-2-octenal, 2-hexanone), which attract bed bugs to safe shelters, and one less-volatile component (histamine), which causes their arrestment upon contact. In infested premises, a blend of all six components is highly effective at luring bed bugs into traps. The trapping of juvenile and adult bed bugs, with or without recent blood meals, provides strong evidence that this unique pheromone bait could become an effective and inexpensive tool for bed bug detection and potentially their control. DOI PubMed
180. Hrabar, M; Zhai, HM; Gries, R; Schaefer, PW; Draper, J; Britton, R; Gries, G. (2015) (7E,11E)-3,5,9,11-Tetramethyltridecadienal: Sex Pheromone of the Strepsipteran Xenos peckii.Journal of Chemical Ecology 41: 732-739 (7E,11E)-3,5,9,11-Tetramethyltridecadienal: Sex Pheromone of the Strepsipteran Xenos peckii
Twisted wing parasite; Strepsiptera; Stylopidia; Xenidae; Xenos peckii endoparasioid; GC-EAD; GC-MS; Sex pheromone; (7E,11E)-3,5,9,11-tetramethyltridecadienal
Xenos peckii is a strepsipteran parasitoid of the common North American paper wasp, Polistes fuscatus. Mate-seeking X. peckii males respond to a long-range sex pheromone emitted by the female, which remains permanently embedded within the abdomen of a mobile host wasp. During peak pheromone signalling, we excised the female from her host, severed the cephalothorax containing the pheromone gland, extracted it in hexane, and analyzed aliquots of combined extracts by coupled gas chromatographic-electroantennographic detection (GC-EAD). These analyses revealed a candidate pheromone component (CPC) that consistently elicited strong responses from male antennae. We identified the CPC as (7E,11E)-3,5,9,11-tetramethyltridecadienal based on its retention indices (RI) on three GC-columns, RI inter-column differentials, mass and NMR spectra, and synthesis of an authentic standard that matched the GC-retention and spectrometric characteristics of the CPC. For a field experiment, we prepared (7E,11E)-3,5,9R,11-tetramethyltridecadienal and (7E,11E)-3,5,9S,11-tetramethyltridecadienal. Xenos peckii males were caught in traps baited with either compound singly or a 1:1 mixture of the two but not in unbaited control traps. The sex pheromone of X. peckii resembles that reported for the strepsipterans Stylops mellittae and S. muelleri, (R,R,R)-3,5,9-trimethyldodecanal, suggesting a common biosynthetic pathway across taxonomic genera. DOI
179. Kathirithamby, J; Hrabar, M; Delgado, JA; Collantes, F; Dotterl, S; Windsor, D; Gries, G. (2015) We do not select, nor are we choosy: reproductive biology of Strepsiptera (Insecta).Biological Journal of the Linnean Society 116: 221-238 We do not select, nor are we choosy: reproductive biology of Strepsiptera (Insecta)
aedeagus; mating behaviour; parasitoids; pheromones; reproductive synchrony; sexual selection
The cryptic entomophagous parasitoids in the order Strepsiptera exhibit specific adaptations to each of the 34 families that they parasitize, offering rich opportunities for the study of male-female conflict. We address the compelling question as to how the diversity of Strepsiptera (where cryptic speciation is common) arose. Studying 13 strepsipteran families, including fossil taxa, we explore the genitalic structures of males, the free-living females of the Mengenillidia (suborder), and the endoparasitic females of the Stylopidia (suborder). Inferring from similarity between aedeagi of males either between congeners, heterogeners, or between species within the same taxonomic family, the same of which is true of the cephalothoraces of females, we predict that male-female conflict and a co-evolutionary morphological arms race between sexes is not likely to exist in most species of Strepsiptera. We then review the non-genitalic structures that play a role during sexual communication, and present details of copulatory behaviour. We conclude that Strepsiptera fall within the synchronous sensory exploitation model where short-lived males take advantage of a pre-existing sensory system involving pheromone signals emitted by females. DOI
178. McCann, S; Moeri, O; Jimenez, SI; Scott, C; Gries, G. (2015) Developing a paired-target apparatus for quantitative testing of nest defense behavior by vespine wasps in response to con- or heterospecific nest defense pheromones.Journal of Hymenoptera Research 46: 151-163 Developing a paired-target apparatus for quantitative testing of nest defense behavior by vespine wasps in response to con- or heterospecific nest defense pheromones
Vespula; yellowjackets; alarm pheromone; defense
Social wasps commonly exhibit impressive, pheromone-mediated nest defenses with stinging attacks on potential vertebrate nest predators. Studying this type of nest defense and comparing results across studies is challenging because there is no standardized method for quantifying defense intensities. For that reason, we developed a simple, paired-target apparatus coupled with easy and inexpensive data recording and analysis technologies. Each target is formed by two conjoined black plastic weigh boats that generate distinct percussive sounds when struck by attacking wasps. A battery-powered microphone inside each target converts the sounds into electrical signals that are transferred to a digital audio recorder. These audio files are then split into left-and right-channel files, saved as 16-bit WAV files, and the strikes to each target are counted using the open-source software SoundRuler. Using this apparatus, we show that workers of Vespula pensylvanica, V. alascensis, and V. germanica strike targets that are treated with conspecific venom sac extract more frequently than paired control targets. We also show that workers of V. alascensis, V. pensylvanica and V. germanica strike targets that are treated with heterospecific extracts more frequently than paired control targets, indicating that the wasps recognize nest alarm pheromones from congeners. These data provide evidence for conserved nest defense pheromones among some Vespula wasps and proof of concept that our technology is capable of quantifying the intensity of pheromone-mediated nest defense behavior in Vespula and other large and formidable social wasps. DOI
177. McCann, S; Scott, C; Jones, T; Moeri, O; O'Donnell, S; Gries, G. (2015) Red-throated Caracara, a falconid raptor, rivals predatory impact of army ants on social wasps.Insectes Sociaux 62: 101-108 Red-throated Caracara, a falconid raptor, rivals predatory impact of army ants on social wasps
Red-throated Caracara; Ibycter americanus; Prey spectrum; Army ants; Eciton; French Guiana
Paper wasps are diverse in Neotropical rainforests but the factors that affect their abundance are poorly understood. Army ants (Ecitoninae) are generally thought to have the greatest predatory impact on populations of social wasps, but there is emerging evidence that predatory birds could also be a significant source of colony mortality. Our objectives were to (1) identify the genera of wasps preyed upon by Ibycter americanus (Falconidae), a specialist predator of Neotropical social wasps, (2) quantify wasp nest predation by I. americanus, and (3) compare wasp nest predation rates by I. americanus with calculated rates of wasp nest predation by Eciton burchellii army ants. In 2008 and 2009, we video recorded chick provisioning at I. americanus nests in French Guiana and found that adult birds brought nests of at least ten genera of mainly swarm-founding wasps (Epiponini). In 2012, we noted that three of four sympatric Eciton species raided into trees and thus potentially preyed upon the brood of paper wasps at the same site. We quantified the population density of one Eciton species, calculated its rate of wasp nest predation, and compared this predation rate to that of I. americanus. We conclude that I. americanus rivals the predatory impact of E. burchellii army ants on some populations of Neotropical social wasps. Ibycter americanus and other diurnal vertebrate predators may exert strong selection on wasp defensive behavior, resulting in defensive adaptations that include selection of specific nest sites as well as physical fortification and visual crypsis of nests. DOI
176. Scott, C; Kirk, D; McCann, S; Gries, G. (2015) Web reduction by courting male black widows renders pheromone-emitting females' webs less attractive to rival males.Animal Behaviour 107: 71-78 Web reduction by courting male black widows renders pheromone-emitting females' webs less attractive to rival males
chemical communication; courtship; Latrodectus hesperus; male-male competition; web reduction
Male adaptations that limit sperm competition include guarding females, applying mating plugs and chemically reducing the attractiveness or receptivity of females. In many web-building spider species, females attract males with silk-borne volatile pheromones. In widow spiders (Latrodectus, 30 species), the courting male often engages in web reduction behaviour during which he excises and bundles sections of the female's web and wraps them with his own silk. Hypothesized functions of this widespread behaviour include sexual communication (e.g. through dissemination of male sex pheromone) and/or decreasing the female's attractiveness to rivals. The latter function was previously demonstrated in a single spider species, Neriene litigiosa, but the extent to which web reduction may decrease male -male competition has never been quantified in the field. In a dense population of western black widows, Latrodectus hesperus, we ran mate attraction experiments to test the hypothesis that web reduction and/or male silk addition decrease web attractiveness to potential rivals. Webs reduced by males attracted three times fewer males than intact webs; webs with a similar proportion of silk experimentally removed attracted as many males as intact webs. However, the experimental addition of male silk did not affect the attractiveness of intact webs. We conclude that web reduction in black widows limits male-male competition by reducing the attraction of rival males to females' webs. This effect is probably mediated through targeted excision of pheromone-laden silk by courting males, possibly in combination with the male's silk forming a physical barrier to pheromone emission. (C) 2015 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved. DOI
175. Scott, C; McCann, S; Gries, R; Khaskin, G; Gries, G. (2015) N-3-Methylbutanoyl-O-methylpropanoyl-L-serine Methyl Ester - Pheromone Component of Western Black Widow Females.Journal of Chemical Ecology 41: 465-472 N-3-Methylbutanoyl-O-methylpropanoyl-L-serine Methyl Ester - Pheromone Component of Western Black Widow Females
Latrodectus; Chemical communication; Pheromone; Amino acid; Silk; Courtship
Chemical communication is common in spiders but few pheromones have been identified. Female widow spiders in the genus Latrodectus spin webs that disseminate an attractive sex pheromone, and a contact pheromone on the silk elicits courtship behavior by males. The methyl ester of N-3-methylbutanoyl-O-(S)-2-methylbutanoyl-L-serine is a contact pheromone of the Australian redback spider Latrodectus hasselti. We hypothesized that the contact pheromone of congeneric L. hesperus resembles that of L. hasselti. The silk of virgin L. hesperus females was extracted with methanol, and analyses by gas chromatography-mass spectrometry (GC/MS) provided evidence for the presence of N-3-methylbutanoyl-O-methylpropanoyl-L-serine methyl ester (MB-MP-S), a lower homologue of the L. hasselti contact pheromone. Behavioral responses of L. hesperus males to test stimuli were assayed on T-shaped rods with the end sections of the horizontal arm enveloped in filter paper. Males spent 40 % longer in contact with paper bearing female silk than with blank paper, and 39 % longer in contact with paper treated with silk extract than with solvent controls. Contact with silk and silk extract induced courtship behavior by 96 % and 80 % of males, respectively, indicating that there was a methanol-soluble courtship-eliciting contact pheromone on the silk. Males responded less strongly to synthetic MB-MP-S than to silk or silk extract. Paper impregnated with synthetic MB-MP-S (10 or 100 mu g) induced courtship behavior in 3-16 % of males, and prompted males to stay 10-16 % longer than on control paper. Our data support the conclusion that MB-MP-S is part of a multi-component contact pheromone of L. hesperus. DOI
174. Ablard, KM; Simonetto, K; Weir, LK; Crespi, BJ; Schaefer, PW; Gries, G. (2014) First-male sperm precedence and precopulatory and postcopulatory rituals in the parasitoid wasp Ooencyrtus kuvanae (Hymenoptera: Encyrtidae).Canadian Entomologist 146: 548-559 First-male sperm precedence and precopulatory and postcopulatory rituals in the parasitoid wasp Ooencyrtus kuvanae (Hymenoptera: Encyrtidae)
Sperm competition generates selection for male traits to prevent it. These traits remain unclear in species where males compete for a virgin who is briefly receptive. Males of the parasitoid wasp Ooencyrtus kuvanae Howard (Hymenoptera: Encyrtidae) compete over females following emergence from host egg masses. Males engage virgins in a precopulatory ritual, mate, and then immediately perform a postcopulatory ritual after which the female becomes unreceptive. Often, sneaker (M-2) males copulate with a female while she is engaged in the postcopulatory ritual, and they also perform the postcopulatory ritual. We investigated (i) paternity of M-1 and M-2 males using DNA microsatellite analysis, (ii) copulation and postcopulatory behaviour of both males, and (iii) morphological adaptations of the aedeagus for sperm removal. Eighty-eight percent of M1 males sired all daughters when they were first to perform the precopulatory and postcopulatory ritual, suggesting a linked effect of both rituals on paternity. The number and length of copulations by both males did not affect paternity, and the shape of the aedeagus does not seem to facilitate sperm removal. Our results are consistent with the hypothesis that postcopulatory rituals represent forms of mate guarding that function to increase paternity in the context of sperm competition. DOI
173. Brodie, B; Gries, R; Martins, A; VanLaerhoven, S; Gries, G. (2014) Bimodal cue complex signifies suitable oviposition sites to gravid females of the common green bottle fly.Entomologia Experimentalis et Applicata 153: 114-127 Bimodal cue complex signifies suitable oviposition sites to gravid females of the common green bottle fly
Lucilia sericata; blow flies; carrion; semiochemical; dimethyl trisulfide; egg-laying site; Diptera; Calliphoridae; GC-EAD
Gravid females of the common green bottle fly, Lucilia sericata Meigen (Diptera: Calliphoridae), readily locate recently deceased vertebrates as oviposition sites, particularly when these animals have been injured. We investigated semiochemical and visual cues that mediate attraction of gravid females to fresh rat carrion. Female flies were more strongly attracted to incised rat carrion than to intact carrion. They were also attracted to Porapak Q headspace volatile (HSV) extract of incised rat carrion. Analyzing aliquots of Porapak Q HSV extract by gas chromatographic-electroantennographic detection revealed nine components [phenol, para- and/or meta-cresol (could not be separated), guaiacol, dimethyl trisulfide (DMTS), phenylacetaldehyde, (E)-2-octenal, nonanal, and tetramethyl pyrazine] that consistently elicited responses from blow fly antennae. In laboratory experiments, a synthetic blend of these nine components was as attractive to gravid females as Porapak Q HSV extract, but blend attractiveness was due entirely to DMTS. In both laboratory and field experiments, increasing doses of DMTS attracted increasingly more flies. Coupled with DMTS, carrion-type color cues (dark red, black) were more effective than bright color cues (white, yellow) in attracting flies. In field experiments, dark traps baited with DMTS captured a total of 214 calliphorid flies (200 L.sericata, 10 Lucilia illustris Meigen, three Calliphora vicina Robineau-Desvoidy, one Calliphora vomitoria L.), all of which were gravid females. These results support the conclusion that DMTS and dark color represent a bimodal cue complex that signifies suitable oviposition sites to gravid calliphorid females, particularly L.sericata. DOI
172. Danci, A; Inducil, C; Takacs, S; Schaefer, PW; Gries, G. (2014) Mechanism of mate detection in parasitoid wasps: sound and vibratory cues change with the developmental progress of future mates inside host pupal cases.Physiological Entomology 39: 292-303 Mechanism of mate detection in parasitoid wasps: sound and vibratory cues change with the developmental progress of future mates inside host pupal cases
Hymenoptera; Ichneumonidae; mate monitoring; Pimpla disparis; pupal parasitoid; sound; vibration
Insects including parasitoid wasps use acoustic and vibratory signals in the context of sexual communication, mate recognition, courtship and mating. Males of the parasitoid wasp Pimpla disparisViereck (Hymenoptera: Ichneumonidae) detect insect host pupae parasitized by a conspecific female, learn their location, visit them repeatedly and remain on or near them when the prospective mate nears emergence. In the present study, the acoustic and vibratory cues that males exploit to detect the presence and track the developmental progress of a future mate inside a host pupal case are investigated. Responses are acquired from developing parasitoids (DePa) by airborne sound and laser Doppler vibrometer recordings, after gently stimulating each of 20 wax moth host pupae with a paintbrush on days 1-23 post parasitism. Sound and vibratory cues produced by DePa are detectable from day 7 onward and relate mostly to spinning movements. Parameters of sound and vibratory cues (amplitude, dominant frequency, upper limit of frequency band) change significantly over time and thus could inform' a visiting adult male about the stage of development of DePa. Adult males antennating a parasitized pupa and flying around it also induce vibrations, which in turn may inform DePa about the presence of a male. There is no experimental evidence for true signalling and rapid information exchange between DePa and adult males. Delaying reply signals may help DePa avoid attacks by illicit receivers of such signals, including female (hyper)parasitoids and invertebrate predators. DOI
171. Hrabar, M; Danci, A; McCann, S; Schaefer, PW; Gries, G. (2014) New findings on life history traits of Xenos peckii (Strepsiptera: Xenidae).Canadian Entomologist 146: 514-527 New findings on life history traits of Xenos peckii (Strepsiptera: Xenidae)
We studied life history traits of Xenos peckii Kirby (Strepsiptera: Xenidae), a little-known parasite of the paper wasp Polistes fuscatus (Fabricus) (Hymenoptera: Vespidae) in North America. We field-collected 24 wasp nests in early July 2012, isolated parasitised wasps, tracked life history events of X. peckii, and recorded such behaviour as emergence of males and mating by normal-speed and high-speed cinematography. To emerge, males first cut the puparium with their mandibles along an ecdysial suture line, and then push aside the pupal cap during emergence. The endoparasitic females engage in active calling (pheromone release) behaviour by slowly inflating their cephalothorax, and then extruding it even farther out of, and tilting it away from, the host wasp abdomen. Seasonal and diel (afternoon) emergence periods of males coincide with seasonal and diel receptivity and calling periods of females. Males approach calling females in a swaying flight with smooth turns. They typically land on the anterior portion of the host wasp's abdomen, and then step backward until they make contact with the cephalothorax of the female. As soon as their mesothoracic legs contact the female's cephalothorax, they curl around it, and the male initiates mating. Thereafter, the female fully retreats and never re-mates. DOI
170. Lambinet, V; Hayden, ME; Bieri, M; Gries, G. (2014) Does the Earth's Magnetic Field Serve as a Reference for Alignment of the Honeybee Waggle Dance?PLOS One 9 Does the Earth's Magnetic Field Serve as a Reference for Alignment of the Honeybee Waggle Dance?
The honeybee (Apis mellifera) waggle dance, which is performed inside the hive by forager bees, informs hive mates about a potent food source, and recruits them to its location. It consists of a repeated figure-8 pattern: two oppositely directed turns interspersed by a short straight segment, the "waggle run''. The waggle run consists of a single stride emphasized by lateral waggling motions of the abdomen. Directional information pointing to a food source relative to the sun's azimuth is encoded in the angle between the waggle run line and a reference line, which is generally thought to be established by gravity. Yet, there is tantalizing evidence that the local (ambient) geomagnetic field (LGMF) could play a role. We tested the effect of the LGMF on the recruitment success of forager bees by placing observation hives inside large Helmholtz coils, and then either reducing the LGMF to 2% or shifting its apparent declination. Neither of these treatments reduced the number of nest mates that waggle dancing forager bees recruited to a feeding station located 200 m north of the hive. These results indicate that the LGMF does not act as the reference for the alignment of waggle-dancing bees. DOI PubMed
169. Mccann, S; Moeri, O; Jones, T; Gries, G. (2014) Black-throated Antshrike preys on nests of social paper wasps in central French Guiana.Revista Brasileira De Ornitologia 22: 300-304 Black-throated Antshrike preys on nests of social paper wasps in central French Guiana
Black-throated Antshrike; predation; social wasps; Polybia; Frederickena viridis
We studied predation by birds on nests of neotropical social paper wasps at the Inselberg camp of the Nouragues Reserve in Central French Guiana, an minimally-disturbed lowland rainforest habitat. Seven meters above ground, we built recording arenas and fitted them with motion-detecting video cameras. We transferred active wasp nests from surrounding forest to the arenas to film bird predators of wasps. In a video recording taken on 13 April 2010, we documented predation by a male Black-throated Antshrike, Frederickena viridis, on nests of Polybia scrobalis and P. bistriata. In rapid fly-bys, the antshrike repeatedly struck the wasp nests with his beak and in the process knocked parts of the nest to the ground. After the wasps absconded, he perched next to the nest of P. bistriata and fed on the wasp larvae and pupae. This predation tactic and type of prey was previously not known for F. viridis. Also, F. viridis apparently forages in higher strata of the forest than previously recorded.
168. Rowland, E; Belton, P; Schaefer, PW; Gries, G. (2014) Intraspecific acoustic communication and mechanical sensitivity of the tympanal ear of the gypsy moth Lymantria dispar.Physiological Entomology 39: 331-340 Intraspecific acoustic communication and mechanical sensitivity of the tympanal ear of the gypsy moth Lymantria dispar
Acoustic signals; intraspecific acoustic communication; laser vibrometry; Lymantria dispar; tympanal ear
Tympanal ears of female gypsy moths Lymantria dispar dispar (L.) (Lepidoptera: Erebidae: Lymantriinae) are reportedly more sensitive than ears of conspecific males to sounds below 20kHz. The hypothesis is tested that this differential sensitivity is a result of sex-specific functional roles of sound during sexual communication, with males sending and females receiving acoustic signals. Analyses of sounds produced by flying males reveal a 33-Hz wing beat frequency and 14-kHz associated clicks, which remain unchanged in the presence of female sex pheromone. Females exposed to playback sounds of flying conspecific males respond with wing raising, fluttering and walking, generating distinctive visual signals that may be utilized by mate-seeking males at close range. By contrast, females exposed to playback sounds of flying heterospecific males (Lymantria fumidaButler) do not exhibit the above behavioural responses. Laser Doppler vibrometry reveals that female tympana are particularly sensitive to frequencies in the range produced by flying conspecific males, including the 33-Hz wing beat frequency, as well as the 7-kHz fundamental frequency and 14-kHz dominant frequency of associated clicks. These results support the hypothesis that the female L. dispar ear is tuned to sounds of flying conspecific males. Based on previous findings and the data of the present study, sexual communication in L. dispar appears to proceed as: (i) females emitting sex pheromone that attracts males; (ii) males flying toward calling females; and (iii) sound signals from flying males at close range inducing movement in females, which, in turn, provides visual signals that could orient males toward females. DOI
167. Vibert, S; Scott, C; Gries, G. (2014) A meal or a male: the 'whispers' of black widow males do not trigger a predatory response in females.Frontiers in Zoology 11 A meal or a male: the 'whispers' of black widow males do not trigger a predatory response in females
Sexual cannibalism; Sexual signalling; Latrodectus hesperus; Black widow spider; Tegenaria agrestis; Hobo spider; Vibration; Spider web
Introduction: Female spiders are fine-tuned to detect and quickly respond to prey vibrations, presenting a challenge to courting males who must attract a female's attention but not be mistaken for prey. This is likely particularly important at the onset of courtship when a male enters a female's web. In web-dwelling spiders, little is known about how males solve this conundrum, or about their courtship signals. Here we used laser Doppler vibrometry to study the vibrations produced by males and prey (house flies and crickets) on tangle webs of the western black widow Latrodectus hesperus and on sheet webs of the hobo spider Tegenaria agrestis. We recorded the vibrations at the location typically occupied by a hunting female spider. We compared the vibrations produced by males and prey in terms of their waveform, dominant frequency, frequency bandwidth, amplitude and duration. We also played back recorded male and prey vibrations through the webs of female L. hesperus to determine the vibratory parameters that trigger a predatory response in females. Results: We found overlap in waveform between male and prey vibrations in both L. hesperus and T. agrestis. In both species, male vibrations were continuous, of long duration (on average 6.35 s for T. agrestis and 9.31 s for L. hesperus), and lacked complex temporal patterning such as repeated motifs or syllables. Prey vibrations were shorter (1.38 - 2.59 s), sporadic and often percussive. Based on the parameters measured, courtship signals of male L. hesperus differed more markedly from prey cues than did those of T. agrestis. Courtship vibrations of L. hesperus males differed from prey vibrations in terms of dominant frequency, amplitude and duration. Vibrations of T. agrestis males differed from prey in terms of duration only. During a playback experiment, L. hesperus females did not respond aggressively to low-amplitude vibrations irrespective of whether the playback recording was from a prey or a male. Conclusions: Unlike courtship signals of other spider species, the courtship signals of L. hesperus and T. agrestis males do not have complex temporal patterning. The low-amplitude 'whispers' of L. hesperus males at the onset of courtship are less likely to trigger a predatory response in females than the high-amplitude vibrations of struggling prey. DOI
166. Ablard, KM; Schaefer, PW; Gries, G. (2013) An alternative reproductive tactic: A parasitoid wasp gathers and guards a harem by pheromone-tagging virgins.Behavioural Processes 94: 32-40 An alternative reproductive tactic: A parasitoid wasp gathers and guards a harem by pheromone-tagging virgins
LOCAL MATE COMPETITION; OOENCYRTUS-KUVANAE; COURTSHIP BEHAVIOR; CHEMICAL COMMUNICATION; NASONIA-VITRIPENNIS; LIMULUS-POLYPHEMUS; SEXUAL SELECTION; MATING TACTICS; BODY-SIZE; HYMENOPTERA
Alternative reproductive tactics (ARTs) are the outcome of decisions to obtain copulations in reproductive competition. Mating tactics male insects exhibit can be based on their competitive ability, or be dependent on conditions such as a competitive setting and the spatial and temporal distribution of receptive females. When females are clustered and numerous, two or more mating tactics can coexist. We predicted that this concept is applicable to the egg parasitoid wasp Ooencyrtus kuvanae (Hymenoptera: Encyrtidae), because wasps emerge en masse as sexually mature adults from gypsy moth, Lymantria dispar, egg masses. We reveal that male O. kuvanae exhibit two ARTs, a mate-at-once (MAO) tactic, and a harem-gathering and -guarding (HGG) tactic. MAO males invariably and immediately mate females they encounter. HGG males (i) typically mate the first receptive female they encounter, (ii) then find and assess other females, (iii) tag those without prior male contact, and finally (iv) return to, and mate with, all females they themselves have tagged. Females do not incur a direct fitness cost by mating with multiply-mated males. HGG males rely on their speed, unique tag pheromone, and on the females' rejection of HGG males except the one that pheromone-tagged them. The tagging pheromone mediates mate recognition and assessment. (c) 2012 Elsevier B.V. All rights reserved. DOI
165. Eby, C; Gardiner, MGT; Gries, R; Judd, GJR; Khaskin, G; Gries, G. (2013) Phenylacetaldehyde attracts male and female apple clearwing moths, Synanthedon myopaeformis, to inflorescences of showy milkweed, Asclepias speciosa.Entomologia Experimentalis et Applicata 147: 82-92 Phenylacetaldehyde attracts male and female apple clearwing moths, Synanthedon myopaeformis, to inflorescences of showy milkweed, Asclepias speciosa
AUTOGRAPHA-GAMMA LEPIDOPTERA; CABBAGE-LOOPER MOTHS; SILVER-Y-MOTH; FLORAL VOLATILES; MACROGLOSSUM-STELLATARUM; FORAGING RESPONSES; MANDUCA-SEXTA; PIERIS-RAPAE; NOCTUIDAE; HAWKMOTH
Synanthedon myopaeformis Borkhausen (Lepidoptera: Sesiidae) is a diurnal clearwing moth native to Eurasia that was recently introduced into British Columbia (BC) and Ontario, Canada, where it has become a serious pest in apple orchards. In BC, these moths commonly feed on nectar of inflorescences, particularly that of showy milkweed, Asclepias speciosa Torrey (Apocynaceae). We investigated the relative importance of visual and olfactory cues, and the key floral semiochemical(s) mediating attraction of S.myopaeformis to A.speciosa. In field experiments, inflorescences left exposed or enclosed in cheesecloth bags dyed green induced similar visitation rates by moths, indicating that olfactory cues are attractive. Among the >10 floral odourants that elicited responses from moth antennae in coupled gas chromatographic-electroantennographic detection analyses, phenylacetaldehyde induced the most frequent proboscis extension reflexes of male and female moths. Among eight floral odourants that were field-tested singly, phenylacetaldehyde attracted 35 times more male and female moths than any other candidate semiochemical. Attractiveness of phenylacetaldehyde could not be enhanced by admixture with other floral odourants at the ratios or concentrations tested indicating that it alone may mediate attraction of S.myopaeformis to the inflorescences of A.speciosa. The potential use of phenylacetaldehyde as bait to monitor or mass-trap populations of male and female S.myopaeformis should be investigated. DOI
164. Eby, C; Weis, M; Gardiner, MGT; Judd, GJR; Gries, G. (2013) Spectral efficiency and microstructure of the compound eyes of Synanthedon myopaeformis (Lepidoptera: Sesiidae).Canadian Entomologist 145: 529-538 Spectral efficiency and microstructure of the compound eyes of Synanthedon myopaeformis (Lepidoptera: Sesiidae)
COLOR-VISION; INFRARED RADIATION; NOCTURNAL HAWKMOTH; SUPERPOSITION EYE; SENSORY CONTROL; LEAF SHAPE; BUTTERFLIES; OPTICS; APPLE; NYMPHALIDAE
The apple clearwing moth, Synanthedon myopaeformis (Borkhausen) (Lepidoptera: Sesiidae), is a day-flying species that feeds on floral nectar of many plants. In British Columbia, Canada, this invasive moth is often observed feeding on visually conspicuous showy milkweed, Asclepias speciosa Torrey (Apocynaceae). We measured the spectral efficiency of the compound eyes of S. myopaeformis in the context of their capacity to discriminate the measured spectral reflectance from inflorescences of A. speciosa, and conducted histological examination of these eyes to determine whether they possess apposition type ommatidia, as commonly observed in diurnal butterflies. Light micrographs of the compound eyes in S. myopaeformis revealed eucone apposition type ommatidia, which is consistent with the diurnal behaviour of the moth. Electroretinograms on compound eyes revealed they were particularly efficient at absorbing ultraviolet (UV) wavelengths in the 335-370 nm range and green wavelengths in the 495-560 nm range. These results support the conclusion that the compound eyes of S. myopaeformis have the capacity for dichromatic vision based on UV and green photoreceptors. However, spectral reflectance curves obtained from inflorescences and foliage of A. speciosa revealed no evidence of UV reflectance, making it less likely that colour plays a primary role in the attraction of S. myopaeformis to A. speciosa. DOI
163. Fitzpatrick, SM; Gries, R; Khaskin, G; Peach, DAH; Iwanski, J; Gries, G. (2013) Populations of the Gall Midge Dasineura oxycoccana on Cranberry and Blueberry Produce and Respond to Different Sex Pheromones.Journal of Chemical Ecology 39: 37-49 Populations of the Gall Midge Dasineura oxycoccana on Cranberry and Blueberry Produce and Respond to Different Sex Pheromones
DIPTERA CECIDOMYIIDAE; TIPWORM DIPTERA; COMPONENTS; LEPIDOPTERA; PHENOLOGY
We identified and field-tested the sex pheromones of Dasineura oxycoccana (Johnson) (Diptera: Cecidomyiidae) midges collected from cranberry, Vaccinium macrocarpon Aiton, and from highbush blueberry, Vaccinium corymbosum L., commonly named cranberry tipworm (CTW) and blueberry gall midge (BGM), respectively. Coupled gas chromatographic-electroantennographic detection (GC-EAD) analyses of pheromone gland extract from the ovipositor of calling CTW females revealed one component (< 10 pg per ovipositor/pheromone gland) that elicited antennal responses from CTW males. Stepwise identification was based on its mass spectrum in a concentrated sample with 300 pheromone gland equivalents, retention indices (RI) on three GC columns (DB-5, DB-23, and DB 210), RI inter-column differentials, and RIs and double bond positions of other midge pheromones. These analyses indicated that (8Z)-2,14-diacetoxy-8-heptadecene (2,14-8Z-17) was the candidate pheromone of the CTW. GC-EAD analysis of pheromone gland extract from calling BGM females revealed two components that elicited antennal responses from BGM males. Retention times on the three GC columns were consistent with 2,14-8Z-17 and 2,14-17, indicating that these were candidate pheromone components of the BGM. The four stereoisomers of 2,14-8Z-17 were stereoselectively synthesized and field-tested in cranberry. Delta-type traps baited with SS-2,14-8Z-17 captured significantly more CTW males than did traps baited with any other single stereoisomer or with all four stereoisomers combined. In blueberry, delta-type traps baited with RR-2,14-8Z-17 captured significantly more BGM males than did traps baited with any other single stereoisomer or with all four stereoisomers combined. Subsequent field experiments demonstrated that RR-2,14-17 is the major pheromone component of BGM, and that RR-2,14-8Z-17 is a pheromone component that does not enhance attractiveness of RR-2,14-17. The BGM pheromone RR-2,14-17 has no antagonistic effect on the CTW pheromone SS-2,14-8Z-17 and vice versa. Our results substantiate the conclusion that populations of D. oxycoccana on cranberry and blueberry represent two cryptic species. DOI
162. Foster, AJ; Hall, DE; Mortimer, L; Abercromby, S; Gries, R; Gries, G; Bohlmann, J; Russell, J; Mattsson, J. (2013) Identification of Genes in Thuja plicata Foliar Terpenoid Defenses.Plant Physiology 161: 1993-2004 Identification of Genes in Thuja plicata Foliar Terpenoid Defenses
WHITE-PINE WEEVIL; HIGH-QUALITY RNA; CONIFER DEFENSE; SITKA SPRUCE; WESTERN REDCEDAR; FUNCTIONAL-CHARACTERIZATION; CHAMAECYPARIS-NOOTKATENSIS; BIOSYNTHESIS; METABOLISM; DEER cedar
Thuja plicata (western redcedar) is a long-lived conifer species whose foliage is rarely affected by disease or insect pests, but can be severely damaged by ungulate browsing. Deterrence to browsing correlates with high foliar levels of terpenoids, in particular the monoterpenoid a-thujone. Here, we set out to identify genes whose products may be involved in the production of a-thujone and other terpenoids in this species. First, we generated a foliar transcriptome database from which to draw candidate genes. Second, we mapped the storage of thujones and other terpenoids to foliar glands. Third, we used global expression profiling to identify more than 600 genes that are expressed at high levels in foliage with glands, but can either not be detected or are expressed at low levels in a natural variant lacking foliar glands. Fourth, we used in situ RNA hybridization to map the expression of a putative monoterpene synthase to the epithelium of glands and used enzyme assays with recombinant protein of the same gene to show that it produces sabinene, the monoterpene precursor of a-thujone. Finally, we identified candidate genes with predicted enzymatic functions for the conversion of sabinene to a-thujone. Taken together, this approach generated both general resources and detailed functional characterization in the identification of genes of foliar terpenoid biosynthesis in T. plicata.Website DOI
161. Schwander, T; Arbuthnott, D; Gries, R; Gries, G; Nosil, P; Crespi, BJ. (2013) Hydrocarbon divergence and reproductive isolation in Timema stick insects.BMC Evolutionary Biology 13 Hydrocarbon divergence and reproductive isolation in Timema stick insects
HOST-PLANT ADAPTATION; CRISTINAE WALKING-STICKS; MALE MATE CHOICE; CUTICULAR HYDROCARBONS; SEXUAL SELECTION; DROSOPHILA-MOJAVENSIS; MORPHOLOGICAL EVOLUTION; CACTOPHILIC DROSOPHILA; INCIPIENT SPECIATION; MATING PREFERENCES
Background: Individuals commonly prefer certain trait values over others when choosing their mates. If such preferences diverge between populations, they can generate behavioral reproductive isolation and thereby contribute to speciation. Reproductive isolation in insects often involves chemical communication, and cuticular hydrocarbons, in particular, serve as mate recognition signals in many species. We combined data on female cuticular hydrocarbons, interspecific mating propensity, and phylogenetics to evaluate the role of cuticular hydrocarbons in diversification of Timema walking-sticks. Results: Hydrocarbon profiles differed substantially among the nine analyzed species, as well as between partially reproductively-isolated T. cristinae populations adapted to different host plants. In no-choice trials, mating was more likely between species with similar than divergent hydrocarbon profiles, even after correcting for genetic divergences. The macroevolution of hydrocarbon profiles, along a Timema species phylogeny, fits best with a punctuated model of phenotypic change concentrated around speciation events, consistent with change driven by selection during the evolution of reproductive isolation. Conclusion: Altogether, our data indicate that cuticular hydrocarbon profiles vary among Timema species and populations, and that most evolutionary change in hydrocarbon profiles occurs in association with speciation events. Similarities in hydrocarbon profiles between species are correlated with interspecific mating propensities, suggesting a role for cuticular hydrocarbon profiles in mate choice and speciation in the genus Timema. DOI
160. Schwander, T; Crespi, BJ; Gries, R; Gries, G. (2013) Neutral and selection-driven decay of sexual traits in asexual stick insects.Proceedings of the Royal Society B-Biological Sciences 280 Neutral and selection-driven decay of sexual traits in asexual stick insects
TIMEMA WALKING-STICKS; WOLBACHIA-INDUCED PARTHENOGENESIS; LEPTOPILINA-CLAVIPES HYMENOPTERA; EVOLUTION; REPRODUCTION; ANCIENT; VESTIGIALIZATION; PHYLOGENETICS; PARASITOIDS; APHELINIDAE
Environmental shifts and lifestyle changes may result in formerly adaptive traits becoming non-functional or maladaptive. The subsequent decay of such traits highlights the importance of natural selection for adaptations, yet its causes have rarely been investigated. To study the fate of formerly adaptive traits after lifestyle changes, we evaluated sexual traits in five independently derived asexual lineages, including traits that are specific to males and therefore not exposed to selection. At least four of the asexual lineages retained the capacity to produce males that display normal courtship behaviours and are able to fertilize eggs of females from related sexual species. The maintenance of male traits may stem from pleiotropy, or from these traits only regressing via drift, which may require millions of years to generate phenotypic effects. By contrast, we found parallel decay of sexual traits in females. Asexual females produced altered airborne and contact signals, had modified sperm storage organs, and lost the ability to fertilize their eggs, impeding reversals to sexual reproduction. Female sexual traits were decayed even in recently derived asexuals, suggesting that trait changes following the evolution of asexuality, when they occur, proceed rapidly and are driven by selective processes rather than drift. DOI
159. Teasdale, C; Judd, GJR; Gries, R; Gries, G. (2013) Evaluation of synthetic sex pheromone for monitoring and management of raspberry crown borer Pennisetia marginata (Lepidoptera: Sesiidae).Agricultural and Forest Entomology 15: 285-293 Evaluation of synthetic sex pheromone for monitoring and management of raspberry crown borer Pennisetia marginata (Lepidoptera: Sesiidae)
LESSER PEACHTREE BORER; SYNANTHEDON-TIPULIFORMIS LEPIDOPTERA; VITACEA-POLISTIFORMIS LEPIDOPTERA; CLEARWING MOTHS LEPIDOPTERA; NIGRICANA F LEPIDOPTERA; MATING DISRUPTION; DOGWOOD BORER; ECTOMYELOIS-CERATONIAE; FLORIDA VINEYARDS; TOBACCO BUDWORM
1 (E,Z)-3,13-Octadecadienal (E3,Z13-18:Ald) was recently identified as a sex pheromone component of the raspberry crown borer Pennisetia marginata (Harris) (Lepidoptera: Sesiidae). Although unstable, this pheromone may have utility for monitoring the seasonal abundance and flight phenology of adult P. marginata, as well as for developing control tactics, such as disorienting mate-seeking males. Experiments conducted in raspberry and blackberry crops tested the effect of lure and trap attributes on captures of male P. marginata. 2 Increasing lure loads (10, 100 or 1000 mu g) of E3,Z13-18:Ald significantly increased trap captures. 3 Freshly prepared lures were significantly more attractive than lures aged for 2-10 days at room temperature. 4 White wing traps and white delta traps were more effective than green delta or green bucket traps. 5 Trap height in the crop canopy had no effect on the capture of males. 6 When sex pheromone components of three other sesiid moth species were added to E3,Z13-18:Ald, the attraction of male P. marginata was reduced and, thus, these components were identified as pheromone antagonists. 7 Pheromone-based mass trapping with 25 wing traps per hectare reduced captures of males in traps baited with a low-dose (10 mu g) pheromone lure by 67-87% in 2011. DOI
158. Wijenberg, R; Hayden, ME; Takacs, S; Gries, G. (2013) Behavioural responses of diverse insect groups to electric stimuli.Entomologia Experimentalis et Applicata 147: 132-140 Behavioural responses of diverse insect groups to electric stimuli
GERMAN-COCKROACH; SEX-PHEROMONE; BLATTELLA-GERMANICA; ELECTRORECEPTION; FIELD; DICTYOPTERA; IDENTIFICATION; COMMUNICATION; LEPIDOPTERA; FISH
Anecdotal evidence suggests that cockroaches respond to electrical appliances or outlets. Our objectives were to determine the effect of field-inducing sources and field attributes on attraction of German cockroaches, Blattella germanica (L.) (Blattodea: Blattellidae), and to test those parameters found effective for attraction of B.germanica for attraction of other groups of insects. In two-choice, large-arena experiments, significantly more female, but not nymphal, B.germanica settled in or near electrified coils with static or fluctuating electromagnetic fields produced by low-level direct current (DC) or alternating current (AC) sources than in control coils without current. Electromagnetic fields with the magnetic, but not the electric, component of the field nulled still attracted B.germanica, suggesting that the electric component of the field may contribute to the attraction or arrestment response of B.germanica. DC-powered coils with static electromagnetic fields also attracted/arrested brown-banded cockroaches, Supella longipalpa (Fabricius) (Blattodea: Blattellidae), common silverfish, Lepisma saccharina (L.), firebrats, Thermobia domestica (Packard) (both Thysanura: Lepismatidae), and European earwigs, Forficula auricularia (L.) (Dermaptera: Forficulidae), but they repelled American cockroaches, Periplaneta americana (L.) (Blattodea: Blattidae). If proven in field experiments, electrified coils as trap baits may offer non-toxic alternatives to pesticides for selective insect control in urban environments. DOI
157. Woodbury, N; Gries, G. (2013) How Firebrats (Thysanura: Lepismatidae) Detect and Nutritionally Benefit From Their Microbial Symbionts Enterobacter cloacae and Mycotypha microspora.Environmental Entomology 42: 860-867 How Firebrats (Thysanura: Lepismatidae) Detect and Nutritionally Benefit From Their Microbial Symbionts Enterobacter cloacae and Mycotypha microspora
THERMOBIA-DOMESTICA ZYGENTOMA; CONFUSED FLOUR BEETLE; CELLULOSE DIGESTION; ARRESTMENT BEHAVIOR; TRIBOLIUM-CONFUSUM; COMMON SILVERFISH; GIANT SILVERFISH; FUNGAL ENZYMES; COLANIC ACID; GUT BACTERIA
The phylogenetically ancient firebrats, Thermobia domestica (Packard) (Thysanura: Lepismatidae), lack any form of long-distance communication, yet are able to locate mates in sustained hot and humid microhabitats, typically within human habitations where they feed on dried goods, including cellulosic substrates. We have recently shown that firebrats aggregate in response to two symbiotic microorganisms in their feces, the bacterium Enterobacter cloacae and the fungus Mycotypha microspora. Our objectives were to determine how firebrats detect M. microspora and E. cloacae, and whether these microbial symbionts nutritionally benefit firebrats. Applied to a glass surface in bioassays, E. cloacae as well as the isolated exopolysaccharide of E. cloacae induced arrestment of firebrats, whereas M. microspora induced arrestment only in the presence of cellulosic substrate. When M. microspora and E. cloacae were grown aerobically on cellulose agar, only M. microspora yielded zones of clearing indicative of enzymatic cellulose degradation. Firebrats also arrested in response to D-glucose, which is a constituent of the exopolysaccharide and which is produced by the cellulase of M. microspora during cellulose degradation. First- to third-instar nymphs of firebrats that were fed E. cloacae, M. microspora, or a nutrient-rich diet developed equally well. By consuming E. cloacae and M. microspora, and by spreading them through feces, firebrats appear able to occupy nutrient-poor habitats that otherwise would not support development of their offspring. DOI
156. Woodbury, N; Gries, G. (2013) Fungal symbiont of firebrats (Thysanura) induces arrestment behaviour of firebrats and giant silverfish but not common silverfish.Canadian Entomologist 145: 543-546 Fungal symbiont of firebrats (Thysanura) induces arrestment behaviour of firebrats and giant silverfish but not common silverfish
THERMOBIA-DOMESTICA; ENTEROBACTER-CLOACAE; MYCOTYPHA MICROSPORA; MICROBIAL SYMBIONTS; GUT BACTERIA; PHEROMONE; DIPTERA; LOCUST; TRANSMISSION; TEPHRITIDAE
We have recently shown that firebrats, Thermobia domestica (Packard) (Thysanura: Lepismatidae), carry, and deposit with their faeces, the symbiotic bacterium Enterobacter cloacae (Jordan 1890) Hormaeche and Edwards 1960 (Enterobacteriaceae) and the symbiotic fungus Mycotypha microspora Fenner, 1932 (Mycotyphaceae), and that these microbes induce arrestment behaviour and aggregation of firebrats. Here, we tested whether giant silverfish, Ctenolepisma longicaudata Escherich (Thysanura: Lepismatidae), and common silverfish, Lepisma saccharina (Linnaeus) (Thysanura: Lepismatidae), also arrest in response to these two microbes. In dual-choice bioassays, E. cloacae arrested firebrats but not giant silverfish or common silverfish, whereas M. microspora arrested firebrats and giant silverfish but not common silverfish. As close relatives, firebrats and giant silverfish have similar microclimate and nutrient requirements and may use M. microspora as the same aggregation cue when they aggregate in hot and humid microclimates where M. microspora proliferates and breaks down cellulose. As a more distant relative to firebrats and giant silverfish, common silverfish seem to require a different as yet unknown aggregation cue or signal, possibly one that is indicative of the type of microclimate (room temperature; high humidity) they prefer. DOI
155. Woodbury, N; Gries, G. (2013) Firebrats, Thermobia domestica, aggregate in response to the microbes Enterobacter cloacae and Mycotypha microspora.Entomologia Experimentalis et Applicata 147: 154-159 Firebrats, Thermobia domestica, aggregate in response to the microbes Enterobacter cloacae and Mycotypha microspora
LEPISMA-SACCHARINA; PACKARD THYSANURA; FUNGAL SYMBIONT; BACTERIA; PHEROMONE; BEHAVIOR; COLEOPTERA; MICROORGANISMS; IDENTIFICATION; STAPHYLINIDAE
The firebrat, Thermobia domestica (Packard) (Thysanura: Lepismatidae), aggregates in response to the faeces of conspecifics as well as shelters previously inhabited by conspecifics. Our objective was to determine the source of the aggregation signal. Filter paper previously exposed to firebrats induced strong arrestment of firebrats. Polar solvents (water, methanol, acetonitrile) and less polar solvents (hexane, dichloromethane, ethyl ether), alone or in combination, failed to extract the aggregation signal from firebrat-exposed paper. Moreover, solvent-extracted paper continued to induce firebrat arrestment. In contrast, the aggregation signal could be obtained by physical extraction (freeze/thawing or ultrasonication) of firebrat-exposed paper submerged in water. Five fungal species and four bacterial species were isolated from ultrasonicant solutions on potato dextrose-, nutrient-, and GlcNAc-agar. Of the nine isolated microbes tested, only the fungus Mycotypha microspora Fenner (Mucorales) and the bacterium Enterobacter cloacae (Jordan) Hormaeche & Edwards (Enterobacteriaceae) induced arrestment of firebrats in bioassays. Our data support the conclusion that firebrats do not form aggregations in response to pheromones; instead, they aggregate in the presence of specific microbes or their metabolites. DOI
154. Woodbury, N; Moore, M; Gries, G. (2013) Horizontal transmission of the microbial symbionts Enterobacter cloacae and Mycotypha microspora to their firebrat host.Entomologia Experimentalis et Applicata 147: 160-166 Horizontal transmission of the microbial symbionts Enterobacter cloacae and Mycotypha microspora to their firebrat host
THERMOBIA-DOMESTICA; SCHISTOCERCA-GREGARIA; MIDGUT EPITHELIUM; DESERT LOCUST; BACTERIA; PROTECTION; MUTUALISM; INSECTS; ANTS
The firebrat, Thermobia domestica (Packard) (Thysanura: Lepismatidae), aggregates in response to the faeces of conspecifics. This aggregation response is mediated by two microbial symbionts, the bacterium Enterobacter cloacae (Jordan) Hormaeche & Edwards (Enterobacteriaceae) and the fungus Mycotypha microspora Fenner (Mucorales). Our objective was to determine how these microbes are transmitted between firebrats. We produced fluorescently labelled E.cloacae and M.microspora and presented them to firebrats. Firebrats consumed large quantities of these labelled microbes and deposited them with their faeces where they proliferated rapidly. Firebrats did not harbour E.cloacae or M.microspora within their ovarioles or eggs, and thus cannot transmit them transovarially. Instead, firebrats acquired them horizontally whenever they fed on microbe-contaminated material, such as faeces, faeces-contaminated paper, or egg surfaces. Firebrats moult throughout their life, and with each moult they shed the cuticular lining of their digestive tract and likely any microbes residing therein. Because firebrats remain in close contact and live in groups of mixed age and gender, newly moulted individuals can readily re-acquire E.cloacae or M.microspora from group members. This ensures the perpetuation of their microbial aggregation and arrestment signal. DOI
153. Ablard K, Gries R, Khaskin G, Gries G. (2012) Does the Stereochemistry of Methylated Cuticular Hydrocarbons Contribute to Mate Recognition in the Egg Parasitoid Wasp Ooencyrtus kuvanae?Journal of Chemical Ecology 38:1306–1317 Does the Stereochemistry of Methylated Cuticular Hydrocarbons Contribute to Mate Recognition in the Egg Parasitoid Wasp Ooencyrtus kuvanae?
Close-range sexual communication of the egg parasitoid wasp Ooencyrtus kuvanae (Hymenoptera: Encyrtidae) takes place on host gypsy moth, Lymantria dispar (Lepidoptera: Lymantriidae), egg masses. We tested the hypothesis that mate recognition in O. kuvanae is mediated, in part, by low-volatility cuticular hydrocarbon (CHC) pheromone components. Gas chromatographic and GC-mass spectrometric analyses of body surface extracts of male and female wasps revealed no sex-specific components, but 5-methylheptacosane (5-me-27Hy) and 5,17-dimethylheptacosane (5,17-dime-27Hy) were consistently more abundant in extracts of males. The ratio of 5-me-27Hy and 5,17-dime-27Hy was similar in extracts of males and females, and quantitative differences alone seemed insufficient to impart sex-specific CHC profiles. Therefore, we further hypothesized that the absolute configuration of 5-me-27Hy and 5,17-dime-27Hy contributes to mate recognition or attraction. As the stereoisomers of 5-me-27Hy and 5,17-dime-27Hy cannot currently be separated chromatographically, we could not determine the stereochemistry of the insect-produced components. Instead, we synthesized all stereoisomers and bioassayed synthetic blends in laboratory experiments. Of eight 2-component blends, each blend containing one of the two enantiomers of 5-me-27Hy and one of the four stereoisomers of 5,17-dime-27Hy, the blend of (5S)-methylheptacosane and (5R,17S)-dimethylheptacosane attracted males, whereas the blend of (5R)-methylheptacosane and (5R,17R)-dimethylheptacosane repelled males. Apparent recognition of both pheromone components and pheromone antagonists by males supports the hypothesis that the stereochemistry of 5-me-27Hy and 5,17-dime-27Hy, and possibly other methylated CHCs, may differ between male and female O. kuvanae, and that these differences may serve in mate attraction and recognition.
DOI
151. Hrabar, M; Danci, A; Schaefer, PW; Gries, G. (2012) In the Nick of Time: Males of the Parasitoid Wasp Pimpla disparis Respond to Semiochemicals from Emerging Mates.Journal of Chemical Ecology 38: 253-261 In the Nick of Time: Males of the Parasitoid Wasp Pimpla disparis Respond to Semiochemicals from Emerging Mates
Pimpla disparis; Mating strategy; Early mate detection; Arrestment behaviour; Mate discrimination; Pheromone evolution
Males of the parasitoid wasp Pimpla disparis Viereck (Hymenoptera: Ichneumonidae) aggregate on parasitized gypsy moth, Lymantria dispar, host pupae when the emergence of a prospective mate is imminent or under way. We tested the hypotheses that the developing parasitoid ("DePa") inside the host pupal case produces a pheromone that attracts and arrests mate-seeking males, and that the pheromone is most effective during the emergence of the parasitoid from the host. Results obtained in two-choice laboratory experiments, with 4-7-d-old virgin males, indicate that (1) DePa-derived semiochemicals arrest males, (2) the opening of a host pupal case strongly arrests males, and (3) the arrestment cue emanates from oral fluid secreted by both female and male parasitoids while they chew their way out of a host pupal case. This phenomenon implies that emerging females, which are haplodiploid and can reproduce without mating, do not engage in active pheromone signaling to attract males, and that mate-seeking males co-opt chemicals involved in eclosion as a mate-finding cue, taking a 50% chance that the prospective mate is a female. DOI
150. Judd, GJR; Gries, R; Teasdale, C; Gries, G. (2012) Identification of a sex pheromone component for Pennisetia marginata (Lepidoptera: Sesiidae).Canadian Entomologist 144: 798-807 Identification of a sex pheromone component for Pennisetia marginata (Lepidoptera: Sesiidae)
STRAWBERRY CROWN-MOTH; BORER LEPIDOPTERA; ATTRACTANTS; ACETATE
Raspberry crown borer, Pennisetia marginata (Harris) (Lepidoptera: Sesiidae), is a native North American species and pest of many cane fruits. Using coupled gas chromatographic-electroantennographic detection analyses (GC-EAD) we identified candidate sex pheromone components in pheromone gland extracts and effluvia from calling females. Analysis of gland extracts on a Zebron-5 column revealed four components (A, B, C, and D) that elicited strong responses from male antennae. The two most EAD-active components A and B were hypothesised to be (3E, 13Z)-octadecadienal [(3E, 13Z)-18:Ald] and (3E, 13Z)-octadecadienol [(3E, 13Z)-18:OH], respectively. Their retention times on other GC columns matched those of authentic standards, thus supporting structural assignments. Synthetic (3E, 13Z)-18:Ald, and its GC rearrangement product (2E, 13Z)-octadecadienal [(2E, 13Z)-18:Ald; component C], also induced antennal responses in GC-EAD analyses of female effluvia. Compounds D in pheromone gland extract, and E and F in female effluvia, elicited EAD responses but could not be identified. In field trapping experiments, (3E, 13Z)-18:Ald was the only component that attracted male P. marginata when tested alone. Attractiveness of (3E, 13Z)-18:Ald was reduced when combined in binary or ternary blends with any of the other identified components, suggesting one or all may act as pheromone antagonists. In Aldergrove, British Columbia, Canada, peak diel attraction of male P. marginata to (3E, 13Z)-18:Ald occurred between 16:00 and 18:00 hours Pacific Daylight Time, at temperatures of 21-23 degrees C, on 30 August 2010, 3 September 2010, and 13 September 2010. We conclude that (3E, 13Z)-18:Ald is the major pheromone component of P. marginata. DOI
149. Miresmailli, S; Gries, R; Gries, G; Zamar, RH; Isman, MB. (2012) Population density and feeding duration of cabbage looper larvae on tomato plants alter the levels of plant volatile emissions.Pest Management Science 68: 101-107 Population density and feeding duration of cabbage looper larvae on tomato plants alter the levels of plant volatile emissions
HIPVs; Trichoplusia ni; tomato; plant-insect interactions; pest monitoring; zNose (TM)
BACKGROUND: As part of their indirect defense, plants under herbivore attack release volatile chemicals that attract natural enemies of the herbivore. This is a very well-documented phenomenon. However, relatively few studies have investigated the response of plants to different population levels of herbivores and their feeding duration. RESULTS: Working with larvae of the cabbage looper, Trichoplusia ni (Hubner), and tomato plants, Lycopersicon esculentum Mill cv. clarence, and using an ultrafast gas chromatograph (the zNose (TM)) for volatile analyses, the authors studied the effect of larval density and feeding duration on levels of plant volatile emissions. Intense herbivory caused higher emission levels of the herbivore-induced plant volatiles (HIPVs) (Z)-3-hexenyl acetate, (E)-beta-ocimene and beta-caryophyllene than those caused by moderate herbivory. When herbivory had ceased following 12-24 h of larval feeding, plants kept releasing HIPVs at a high level for a longer period of time than they did following only 6 h of larval feeding. The plants' slow adjustment in their volatile emissions following prolonged larval feeding might be strategic, as such feeding is more likely to have ceased just temporarily. CONCLUSION: This information may help in the development of a pest monitoring system that is based on herbivore-induced plant volatiles. (C) 2011 Society of Chemical Industry DOI
148. Scott, C; Vibert, S; Gries, G. (2012) Evidence that web reduction by western black widow males functions in sexual communication.Canadian Entomologist 144: 672-678 Evidence that web reduction by western black widow males functions in sexual communication
A well-accepted function of courtship in sexually dimorphic and cannibalistic spiders is suppression of female predatory responses. We quantitatively analysed courtship in the western black widow, Latrodectus hesperus Chamberlin and Ivie (Araneae: Theridiidae), to determine the behavioural elements of the males' courtship that are correlated with mating success and/or the females' responses. The 58% of males that engaged in web reduction elicited fewer aggressive responses from females and induced female quiescence more quickly than did males not exhibiting web reduction behaviour. Our data suggest that web reduction by male L. hesperus functions in sexual communication, a context not previously explored. DOI
147. Zahradnik, T; Takacs, S; Strong, W; Bennett, R; Kuzmin, A; Gries, G. (2012) Douglas-fir cone gall midges respond to shape and infrared wavelength attributes of host tree branches.Canadian Entomologist 144: 658-666 Douglas-fir cone gall midges respond to shape and infrared wavelength attributes of host tree branches
We tested the hypothesis that the conophagous Douglas-fir cone gall midge, Contarinia oregonensis Foote (Diptera: Cecidomyiidae), responds to infrared (IR) radiation and other electromagnetic wavelengths associated with cones of Douglas-fir, Pseudotsuga menziesii (Mirbel) Franco (Pinaceae). Early-season (March-April) thermographic images showed that cone orientation (upright, horizontal, pendant) and cone colour (green, purple, green/purple) did not affect apparent cone temperature (inferred from thermographic images). Tree components significantly differed in apparent temperature with foliage being coolest and branches warmest. There was no significant difference in the number of larvae in cones of different colours, and adult midges were equally attracted to traps painted green or purple, suggesting that cone colour does not affect oviposition decisions by gravid females. Adult midges were more strongly attracted to warm traps with IR frequency emissions higher than the background than to cold traps with IR frequency emissions lower than the background. They were also more strongly attracted to warm branch-shaped traps than to warm can-shaped traps. Collectively, these data indicate that the shape and IR attributes of Douglas-fir branches may serve as foraging cues for C. oregonensis. DOI
146. Ablard, K; Fairhurst, S; Andersen, G; Schaefer, P; Gries, G. (2011) Mechanisms, functions, and fitness consequences of pre- and post-copulatory rituals of the parasitoid wasp Ooencyrtus kuvanae.Entomologia Experimentalis et Applicata 140: 103-111 Mechanisms, functions, and fitness consequences of pre- and post-copulatory rituals of the parasitoid wasp Ooencyrtus kuvanae
egg parasitoid; mating ritual; mate guarding; trance; courtship; intraspecific competition; pheromone; mechanical; Hymenoptera; Encyrtidae
Males and females of the parasitoid wasp Ooencyrtus kuvanae (Howard) (Hymenoptera: Encyrtidae) emerge en masse from gypsy moth, Lymantria dispar dispar (L.) (Lepidoptera: Noctuidae: Lymantriinae), host egg masses. Males engage females in a brief pre-copulatory ritual, mate, and then execute a post-copulatory ritual. We investigated mechanisms, functions, and fitness consequences of the pre- and post-copulatory ritual by high-speed cinematography, gas chromatographic-mass spectrometric analyses of volatile constituents on the insects' integument, and behavioral assays. Our data indicate that the mechanisms of the pre- and post-copulatory ritual are physical interactions rather than pheromone transfer. During the pre-copulatory ritual, the males put females into a trance-like state that persists for some time after copulation. Males attained a mating with in-trance females 9.5 times faster than with females that had come out of trance. Mated females with post-copulatory ritual experience did not remate, whereas females lacking that experience did. The total number of offspring and daughters did not differ between females with or without post-copulatory ritual experience or in relation to the duration of that ritual. The post-copulatory ritual functions as a form of mate guarding in that the male accelerates awakening of the in-trance female, which then rejects mating attempts by other males, ensuring his paternity. DOI
145. Birmingham, AL; Kovacs, E; Lafontaine, JP; Avelino, N; Borden, JH; Andreller, IS; Gries, G. (2011) A New Trap and Lure for Drosophila melanogaster (Diptera: Drosophilidae).Journal of Economic Entomology 104: 1018-1023 A New Trap and Lure for Drosophila melanogaster (Diptera: Drosophilidae)
trap; natural lure; Drosophila
We conducted a series of nine laboratory experiments testing the response of "vinegar flies," Drosophila melanogaster Meigen (Diptera: Drosophilidae), released in bioassay chambers to experimental traps and lures. These experiments showed that an effective trap could be constructed from a clear 225-ml screw-cap jar fitted with a hollow 8-mm-diameter cylindrical cross bridge. Flies could enter the trap from either end of the cylindrical "gate" and in turn could enter the interior chamber of the trap through a cut out portion at mid-span of the cylinder. The experiments also showed that a natural-component lure could be made using a teabag containing freeze-dried banana powder, yeast, and carrageenan gum powder as a humectant. When dipped in water for 10-15 s and then placed in the bottom of a trap, the teabag provided effective attraction for at least 7 d. Captured flies were immobilized on a sticky card placed in the trap, allowing them to be easily seen. Unlike other traps that cannot be opened and have liquid lures, the cylindrical-gate trap can be reused repeatedly if the teabag and sticky card are replaced. A final two experiments showed that the prototype operational cylindrical-gate trap with a teabag lure captured 3.3 and 2.3 times more released flies, respectively, than the next best of three commercially available traps. DOI
144. Campbell, C; Gries, R; Gries, G. (2011) Forty-two compounds in eleven essential oils elicit antennal responses from Aedes aegypti.Entomologia Experimentalis et Applicata 138: 21-32 Forty-two compounds in eleven essential oils elicit antennal responses from Aedes aegypti
gas chromatographic-electroantennographic detection; mosquito; repellence; electrophysiology; GC-EAD; Diptera; Culicidae; yellow fever; minor constituents
Essential oils of various plants can be effective at repelling mosquitoes. The repellent properties are often ascribed to their dominant constituents. Our objective was to analyse several essential oils by coupled gas chromatographic-electroantennographic detection (GC-EAD) on the premise that those compounds that are detected by the antennae of the yellow fever mosquito, Aedes aegypti L. (Diptera: Culicidae), are candidate repellents even though they may be minor constituents and thus be overlooked in GC-mass spectrometric analyses of essential oils. In the essential oils of catnip, cinnamon, citronella, cumin, eucalyptus, geranium, ginger, melissa, peppermint, rosemary, and thyme, 42 components induced antennal responses, most commonly beta-caryophyllene, linalool, 1,8-cineole, geraniol, and geranial. Some of these 42 components are known insect repellents, indicating that GC-EAD screening of essential oils is a viable analytical technique to detect quantitatively minor constituents, which could be potent repellents when tested at an appropriate dose. DOI
143. Campbell, C; Gries, R; Khaskin, G; Gries, G. (2011) Organosulphur constituents in garlic oil elicit antennal and behavioural responses from the yellow fever mosquito.Journal of Applied Entomology 135: 374-381 Organosulphur constituents in garlic oil elicit antennal and behavioural responses from the yellow fever mosquito
Aedes aegypti; Allium sativum; essential oil; garlic; repellent; yellow fever mosquito
Garlic (Allium sativum) and its essential oil have long been used for their distinct flavour, therapeutic effects and as a topical and systemic insect repellent. We tested the hypothesis that the yellow fever mosquito, Aedes aegypti L. (Diptera: Culicidae), responds electrophysiologically and behaviourally to specific components of the steam-distilled essential oil of garlic. In coupled gas chromatographic-electroantennographic detection analyses of garlic oil, antennae of female Ae. aegypti responded to 14 compounds. Seven of them [diallyl disulphide, diallyl trisulphide, diallyl tetrasulphide, 2-(2,3-dithia-5-hexenyl)-3,4-dihydro-2H-thiopyran, 3-(2,3-dithia-5-hexenyl)-3,4-dihydro-2H-thiopyran, 6-methyl-4,5,8,9-tetrathiadodeca-1,11-diene and 4,5,9,10-tetrathiatrideca-1,12-diene] were isolated or synthesized and tested for their ability to repel host-seeking female Ae. aegypti. A solution of diallyl trisulphide and diallyl tetrasulphide applied to a human forearm provided protection from female mosquitoes significantly longer than the paraffin oil control. All compounds had mean protection times significantly shorter than an equivalent dose of the 'gold standard'N,N-diethyl-3-methylbenzamide. Understanding the common moiety in organosulfur compounds that causes repellence could lead to the design of analogues that are more effective than their natural counterparts in repelling mosquitoes. DOI
142. Danci, A; Inducil, C; Schaefer, PW; Gries, G. (2011) Early Detection of Prospective Mates by Males of the Parasitoid Wasp Pimpla disparis Viereck (Hymenoptera: Ichneumonidae).Environmental Entomology 40: 405-411 Early Detection of Prospective Mates by Males of the Parasitoid Wasp Pimpla disparis Viereck (Hymenoptera: Ichneumonidae)
Pimpla disparis; early mate detection; marker pheromone
In some insect species, the presence of a mate at the time of eclosion appears to facilitate rapid mating, with positive fitness consequences for one or both mates. Field observations that males of the hymenopteran parasitoid Pimpla disparis Viereck aggregated on a gypsy moth, Lymantria dispar (L.), host pupa before the emergence of a female led us to hypothesize that these males responded to chemical cues associated with parasitized host pupae. Results of laboratory experiments with wax moth, Galleria mellonella (L.), host pupae suggest that female P. disparis chemically mark the host pupae they have parasitized and that males discern between such pupae and those not parasitized. As males continue to recognize parasitized host pupae throughout the development of the parasitoid, they could exploit not only the females' marker pheromone but possibly also semiochemical, visual, or vibratory cues from the developing parasitoid inside the host pupa, the decaying host, or both. Irrespective, these cues could help males locate parasitized host pupae and time the emergence of a prospective mate. DOI
141. Judd, GJR; Gries, R; Aurelian, VM; Gries, G. (2011) 3Z, 13Z-octadecadienyl acetate: sex pheromone of the apple clearwing moth in British Columbia.Canadian Entomologist 143: 236-244 3Z, 13Z-octadecadienyl acetate: sex pheromone of the apple clearwing moth in British Columbia
The apple clearwing moth, Synanthedon myopaeformis (Borkhausen) (Lepidoptera: Sesiidae), is a European species discovered in Cawston, British Columbia, Canada, in 2005. Using coupled gas chromatographic - electroantennographic detection analyses we identified candidate sex pheromone components in pheromone gland extracts and effluvia from calling females. Analysis of gland extracts using four gas-chromatography (GC) columns (DB-5, DB-17, DB-23, and DB-210) showed three components (A, B, and C) that consistently elicited strong responses from male antennae. Based on previous work, the most antennally stimulatory component, B, was hypothesized to be (3Z,13Z)-octadecadienyl acetate ((3Z,13Z)-18:OAc). Its retention time on the four GC columns and its mass spectrum in a concentrated extract matched those of an authentic standard, thus confirming structural assignment. Components A and C were below the detection threshold of the mass spectrometer, but their retention times on the four GC columns matched those of authentic standards of (3Z,13Z)-octadecadienol ((3Z,13Z)-18:OH) and (2E,13Z)-octadecadienyl acetate ((2E, I 3Z)-18:OAc), respectively. Synthetic (3Z,13Z)-18:OAc, (3Z,13Z)-18:OH, and (2E,I 3Z)-18:OAc all elicited strong responses from male antennae, further supporting structural assignments of these three components. Of these antennally active compounds, only (3Z,13Z)-18:OAc and (3Z,13Z)-18:OH were detected in effluvia from calling female moths. In field trapping tests in Cawston, (3Z,13Z)-18:OAc alone was as attractive as, or more attractive than, binary or ternary blends containing this component. (2E,13Z)-18:OAc was behaviourally inactive alone or in combination with (3Z,13Z)-18:OAc, whereas 5% (3Z,13Z)-18:OH appeared antagonistic. Our analysis confirms that (3Z,13Z)-18:OAc is the major pheromone component in S. myopaeformis, and it alone is sufficiently attractive for use in detection surveys and development of pheromone-based controls for this introduced pest in Canada. DOI
140. Jumean, Z; Ma, BO; Chubaty, AM; Ellenor, CW; Roitberg, BD; Gries, G. (2011) A Theoretical Approach to Study the Evolution of Aggregation Behavior by Larval Codling Moth, Cydia pomonella (Lepidoptera: Tortricidae).Journal of Insect Behavior 24: 249-263 A Theoretical Approach to Study the Evolution of Aggregation Behavior by Larval Codling Moth, Cydia pomonella (Lepidoptera: Tortricidae)
Codling moth larva; aggregation; evolution; genetic algorithm
Pupation site-seeking larvae of the codling moth, Cydia pomonella, aggregate in response to aggregation pheromone produced by cocoon-spinning conspecific larvae. Larvae that pupate in an aggregation rather than in solitude may experience a lower rate of parasitism by the parasitoid Mastrus ridibundus. Additionally, adults eclosing from a larval aggregation may encounter mates more rapidly at the site of eclosion (on-site) than away from that site (off-site). We employed an evolutionary simulation to determine the effect of several ecological parameters on the evolution of larval aggregation behavior. These parameters included (i) the probability of mate encounter off-site; (ii) the time available for finding a mate; and (iii) the population density of parasitoids and their rate of larval parasitism. The model predicts that larval aggregation behavior is selected for when the probability of off-site mate encounter is low, the time to locate mates is short, and egg-limited parasitoids are at high population levels. We also show that aggregations reduce the risk of parasitism through dilution effects. The parameters found to favour the evolution of larval aggregation behavior are consistent with life history traits exhibited by C. pomonella. DOI
139. Karimifar, N; Gries, R; Khaskin, G; Gries, G. (2011) General Food Semiochemicals Attract Omnivorous German Cockroaches, Blattella germanica.Journal of Agricultural and Food Chemistry 59: 1330-1337 General Food Semiochemicals Attract Omnivorous German Cockroaches, Blattella germanica
Peanut butter; beer; 1-hexanol; ethanol; 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one
Stale beer and peanut butter are effective baits for the German cockroach (GCRs), Blattella germanica (L.) (Dictyoptera: Blattellidae). In still-air arena olfactometer experiments it was previously shown that headspace volatile extracts of peanut butter and solvent extract of beer attract male GCRs. The objective of this study was to identify the semiochemicals that mediate attraction of GCRs to these sources. Coupled gas chromatographic-electroantennographic detection (GC-EAD) and GC-mass spectrometric (MS) analyses of these attractive extracts, or fractions thereof, and of synthetic standards revealed many candidate semiochemicals. Elaborate olfactometer experiments determined that 1-hexanol from peanut butter, and ethanol and 2, 3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one (DDMP) from beer, are the key semiochemicals of these food sources. 1-Hexanol is a well-known headspace volatile of decomposing lipids, ethanol conveys food fermentation, and DDMP with a caramel-type flavor has been found in several types of food. By responding to these rather general food-derived compounds, the omnivorous GCRs appear to exploit semiochemicals that indicate the presence of various food components, such as lipids and carbohydrates. Synthetic equivalents of these semiochemicals may be formulated as baits or be added to, and thus enhance the attractiveness of, natural food sources as trap or insecticidal baits. DOI
138. Rowland, E; Schaefer, PW; Belton, P; Gries, G. (2011) Evidence for short-range sonic communication in lymantriine moths.Journal of Insect Physiology 57: 292-299 Evidence for short-range sonic communication in lymantriine moths
Lymantria monacha; Lymantria fumida; Lymantria mathura; Lepidoptera; Noctuidae; Lymantriinae; Acoustic communication; Short range orientation behaviour; Acoustic signals; Tympanate ear; Laser interferometry
Sexual communication of nun moth, Lymantria monacha (L), pink gypsy moth, Lymantria mathura Moore, and fumida tussock moth, Lymantria fumida Butler (all Lepidoptera: Noctuidae: Lymantriinae), is known to be mediated by pheromones. We now show that males are attracted by the sounds of conspecific females over short distances and that wing fanning male and female L monacha, L. mathura and L fumida produce species- and sex-specific wing beat and associated click sounds that could contribute to reproductive isolation. Evidence for short-range communication in these lymantriines includes (i) scanning electron micrographs revealing metathoracic tympanate ears, (ii) laser interferometry showing particular sensitivity of tympana tuned to frequency components of sound signals from conspecifics, and (iii) phonotaxis of male L monacha and L. fumida to speakers playing back sound signals from conspecific females. We conclude that tympanate ears of these moths have evolved in response not only to bat predation, but also for short-range mate finding and possibly recognition. (C) 2010 Elsevier Ltd. All rights reserved. DOI
137. Somjee, U; Ablard, K; Crespi, B; Schaefer, PW; Gries, G. (2011) Local mate competition in the solitary parasitoid wasp Ooencyrtus kuvanae.Behavioral Ecology and Sociobiology 65: 1071-1077 Local mate competition in the solitary parasitoid wasp Ooencyrtus kuvanae
Local mate competition; Ooencyrtus kuvanae; Solitary egg parasitoid; Sex ratio; Local resource
Local mate competition (LMC) occurs when brothers compete with each other for mating opportunities, resulting in selection for a female-biased sex ratio within local groups. If multiple females oviposit in the same patch, their sons compete for mating opportunities with non-brothers. Females, in the presence of other females, should thus produce relatively more sons. Sex ratio theory also predicts a more female-biased sex ratio when ovipositing females are genetically related, and sex-ratio responses to foundress size if it differentially affects fitness gains from sons versus daughters. The mating system of the parasitoid wasp Ooencyrtus kuvanae meets assumptions of LMC. Females insert a single egg into each accessible egg of gypsy moth, Lymantria dispar, host egg masses. Wasps complete development inside host eggs and emerge en masse, as sexually mature adults, resulting in intense competition among brothers. We tested the hypothesis that O. kuvanae exhibits LMC by manipulating the number of wasp foundresses on egg masses with identical numbers of eggs. As predicted by LMC theory, with increasing numbers of wasp foundresses on an egg mass, the proportions of emerging sons increased. In contrast, the presence of a sibling compared to a non-sibling female during oviposition, or the size of a female, did not affect the number or sex ratio of offspring produced. The O. kuvanae system differs from others in that larvae do not compete for local resources and thus do not distort the sex ratio in favor of sons. With no resource competition among O. kuvanae larvae, the sex ratio of emergent son and daughter wasps is due entirely to the sex allocation by ovipositing wasp foundresses on host egg masses.Website DOI
136. Campbell, C; Gries, G. (2010) Is soybean oil an effective repellent against Aedes aegypti?Canadian Entomologist 142: 405-414 Is soybean oil an effective repellent against Aedes aegypti?
Soybean oil (SO) is considered an active ingredient in commercial BiteBlocker (TM) insect-repellent products. Our objective was to test mechanisms by which SO exhibits repellency, using the yellow fever mosquito, Aedes aegypti (L.) (Diptera: Culicidae), as a representative blood-feeding insect. In dual-port glass-cage olfactometers, human hands treated with SO at various concentrations attracted as many mosquitoes as did untreated hands, indicating that SO has no long-range repellent effect. In contrast, hands treated with N,N-diethyl-3-methylbenzamide (DEET) attracted significantly fewer mosquitoes than did untreated control hands. In cage experiments, treating an area of a human forearm exposed to A. aegypti with SO provided no protection against bites, whereas treating it with DEET did. These results indicate that SO has no short-range or contact repellent properties. Both DEET and the BiteBlocker (TM) product conferred protection for periods similar to those previously reported. Based on our data, classification of SO as an active mosquito repellent should be reconsidered. DOI
135. Danci, A; Takacs, S; Schaefer, PW; Gries, G. (2010) Evidence for acoustic communication in the parasitoid wasp Glyptapanteles flavicoxis.Entomologia Experimentalis et Applicata 136: 142-150 Evidence for acoustic communication in the parasitoid wasp Glyptapanteles flavicoxis
wing fanning; near-field sound; acoustic signals; sex pheromone; mating behavior; Hymenoptera; Braconidae
Females of the parasitoid wasp Glyptapanteles flavicoxis (Marsh) (Hymenoptera: Braconidae) deposit sex pheromone on substrate that elicits attraction and wing fanning in conspecific males. We tested the hypothesis that wing fanning sound induces a behavioral response from females which, in turn, affects the males' orientation toward them. Females exposed to playback of the males' wing fanning sound engaged in short flights, with sound characteristics different from those of the males' wing fanning sound. In two-choice bioassays, playback of the females' flight sound attracted significantly more males than a silent control stimulus, and in combination with pheromone-containing body extract of females it attracted more males than female body extract alone. Our data support the conclusion that the males' wing fanning induces sound and visual reply signals from females that help males orient toward them. DOI
133. Lam, K; Tsang, M; Labrie, A; Gries, R; Gries, G. (2010) Semiochemical-Mediated Oviposition Avoidance by Female House Flies, Musca domestica, on Animal Feces Colonized with Harmful Fungi.Journal of Chemical Ecology 36: 141-147 Semiochemical-Mediated Oviposition Avoidance by Female House Flies, Musca domestica, on Animal Feces Colonized with Harmful Fungi
House flies; Musca domestica; Phoma spp.; Rhizopus spp.; Fungi; Animal feces; Resource competition; Oviposition; Semiochemicals; Dimethyl trisulfide; 2-Phenylethanol
House flies, Musca domestica, utilize ephemeral resources such as animal feces for oviposition and development of larval offspring, but they face competition with fungi that colonize the same resource. We predicted that house flies avoid oviposition on feces well-colonized with fungi, thereby reducing fungal competition for larval offspring. Working with fungal isolates from chicken feces, we have previously shown that prior establishment of Phoma spp., Fusarium spp., or Rhizopus spp. on feces significantly reduced oviposition by house flies. Here, we report that, in the headspace volatiles of these three fungal genera, five compounds (dimethyl trisulfide, an unknown, 2-phenylethanol, citronellal, norphytone) elicit responses from house fly antennae. In behavioral bioassays, dimethyl trisulfide and 2-phenylethanol significantly reduced oviposition by house flies. We conclude that fungus-derived volatiles serve as semiochemical cues that help house flies avoid resources colonized with fungal competitors for the development of larval offspring. DOI
132. McCann, S; Moeri, O; Jones, T; O'Donnell, S; Gries, G. (2010) NESTING AND NEST-PROVISIONING OF THE RED-THROATED CARACARA (IBYCTER AMERICANUS) IN CENTRAL FRENCH GUIANA.Journal of Raptor Research 44: 236-240 NESTING AND NEST-PROVISIONING OF THE RED-THROATED CARACARA (IBYCTER AMERICANUS) IN CENTRAL FRENCH GUIANA
Red-throated Caracara; Ibycter americanus; cooperative breeding; diet; French Guiana; nesting; nest-provisioning
131. Miresmailli, S; Gries, R; Gries, G; Zamar, RH; Isman, MB. (2010) Herbivore-induced plant volatiles allow detection of Trichoplusia ni (Lepidoptera: Noctuidae) infestation on greenhouse tomato plants.Pest Management Science 66: 916-924 Herbivore-induced plant volatiles allow detection of Trichoplusia ni (Lepidoptera: Noctuidae) infestation on greenhouse tomato plants
HIPVs; pest monitoring; greenhouse tomato; Trichoplusia ni; zNose (TM)
BACKGROUND: Monitoring of insect populations is an important component of integrated pest management and typically is based on the presence and number of insects in various development stages. Yet plants respond to insect herbivory and release herbivore-induced plant volatiles (HIPVs), which could be exploited in monitoring systems. The present objective was to investigate whether the information associated with HIPVs has potential to become part of advanced technologies for monitoring pest insect populations. RESULTS: In a laboratory experiment, it was determined that tomato plants, Lycopersicon esculentum Mill cv. clarence, each infested with 20 caterpillars of the cabbage looper, Trichoplusia ni (Hubner), emit HIPVs, of which (Z)-3-hexenyl acetate, (E)-beta-ocimene and beta-caryophyllene were selected as chemicals indicative of herbivory. Using an ultrafast portable gas chromatograph (zNose (TM)) in a research greenhouse and in a commercial greenhouse, it was possible (i) to reveal differential emissions of these three indicator chemicals from plants with or without herbivory, (ii) to detect herbivory within 6 h of its onset, (iii) to track changes in indicator chemical emissions over time and (iv) to study the effect of environmental and crop-maintenance-related factors on the emission of indicator chemicals. CONCLUSION: HIPVs appear to be promising as reliable indicators of plant health, but further studies are needed to fully understand the potential of this concept. (C) 2010 Society of Chemical Industry DOI
130. Schwarz, JJ; Gries, G. (2010) 2-Phenylethanol: context-specific aggregation or sex-attractant pheromone of Boisea rubrolineata (Heteroptera: Rhopalidae).Canadian Entomologist 142: 489-500 2-Phenylethanol: context-specific aggregation or sex-attractant pheromone of Boisea rubrolineata (Heteroptera: Rhopalidae)
Western boxelder bugs, Boisea rubrolineata (Barber), form large aggregations on pistillate boxelder, Acer negundo L. (Aceraceae), host trees with maturing seeds, and cluster on warm, sunlit surfaces prior to overwintering. We have recently shown that B. rubrolineata is attracted to the host-tree semiochemicals phenylacetonitrile and 2-phenethyl acetate. We report results of chemical analyses and laboratory bioassays suggesting that aggregation and sexual communication in B. rubrolineata are mediated by 2-phenylethanol. This compound serves as an aggregation pheromone for females, males, and 5th-instar nymphs in midsummer, and in males it appears to serve as a sex-attractant pheromone in early spring. As an aggregation pheromone, 2-phenylethanol originates from the feces of seed-feeding females and males and (or) the ventral abdominal gland of males. As a sex-attractant pheromone, it originates from the ventral abdominal gland of males that emerge from overwintering diapause. Aggregations of B. rubrolineata in the fall and winter are mediated by other as yet unknown pheromones. DOI
129. van Herk, WG; Vernon, RS; Harding, C; Roitberg, BD; Gries, G. (2010) Possible aversion learning in the Pacific Coast wireworm.Physiological Entomology 35: 19-28 Possible aversion learning in the Pacific Coast wireworm
aversion learning; behaviour; insecticide; Limonius canus; repellency; wireworm
The effects of carbon dioxide and the induction of morbidity on aversion learning in larvae of the Pacific Coast wireworm Limonius canus LeConte (Coleoptera: Elateridae) are discussed. Wireworms preconditioned by exposing them one or four times to odour of Tefluthrin 20SC and Dividend XLRTA [Syngenta Crop Protection (Canada), Inc., Canada] during the induction of temporary morbidity subsequently contact tefluthrin-treated wheat seeds in soil bioassays for as long as naive (i.e. not preconditioned) larvae but are repelled four to five-fold more frequently by Dividend-treated seeds in soil bioassays than naive wireworms, suggesting that wireworms are capable of associating a novel odour (i.e. Dividend) with morbidity but require a minimum of 10-15 min subsequent contact time with treated seeds before being repelled. Wireworms preconditioned by exposure to peppermint odour during the induction of morbidity are not subsequently repelled by peppermint odour in soil bioassays, suggesting that wireworms are either not capable of aversion learning or that the presence of a CO2 source and/or a suitable host plant may override a negative cue (i.e. peppermint odour). In studies conducted in the absence of soil, a host plant and CO2 production, wireworms are repelled slightly by droplets of 1.0% but not 0.1% peppermint oil. Previous exposure to peppermint odour or contact with peppermint oil-treated filter paper during one induction of morbidity does not increase the repellency of wireworms to 1.0% peppermint oil significantly. Repellency to 1.0% peppermint oil is almost eliminated when morbidity is induced five times in the absence of peppermint odour but is restored when peppermint odour is present during preconditioning. These findings suggest that wireworm sensitivity to repellent compounds decreases when repeatedly made moribund, although the results are not sufficient to conclude that wireworms are capable of associative learning. DOI
128. Britton, R; Khaskin, G; Gries, G. (2009) A chromatography-free synthesis of (2S, 12Z)-2-acetoxy-12-heptadecene - The major sex pheromone component of the pistachio twig borer moth (Kermania pistaciella).Canadian Journal of Chemistry-Revue Canadienne de Chimie 87: 430-432 A chromatography-free synthesis of (2S, 12Z)-2-acetoxy-12-heptadecene - The major sex pheromone component of the pistachio twig borer moth (Kermania pistaciella)
synthesis; pheromone; (2S, 12Z)-2-acetoxy-12-heptadecene; chromatography-free
Recently, (2S, 12Z)-2-acetoxy-12-heptadecene was identified as the major sex pheromone component of the pistachio twig borer moth, Kermania pistaciella, one of the most serious insect pests of pistachio plantations in Iran and Turkey. In field studies, an attract-and-kill formulation containing (2S, 12Z)-2-acetoxy-12-heptadecene demonstrated efficacy in reducing damage caused by K. pistaciella and may become a widely-used, earth-friendly tactic for control of this insect in commercial pistachio production. To further develop this technology, a cost-effective, chromatography-free synthesis of (2S, 12Z)-2-acetoxy-12-heptadecene was required and is described in this communication.PDF DOI
127. Cowan, T; Gries, G. (2009) Ultraviolet and violet light: attractive orientation cues for the Indian meal moth, Plodia interpunctella.Entomologia Experimentalis et Applicata 131: 148-158 Ultraviolet and violet light: attractive orientation cues for the Indian meal moth, Plodia interpunctella
STORED-PRODUCT INSECTS; EPHESTIA-CAUTELLA; PYRALID MOTHS; BEHAVIOR; LEPIDOPTERA; RESPONSES; COMPASS; PERFORMANCE; NAVIGATION; PHEROMONE
The Indian meal moth (IMM), Plodia interpunctella (Hubner) (Lepidoptera: Pyralidae), engages in long-distance or foraging flights in the twilight hours of the scotophase when blue light dominates the irradiance spectrum of the sky. We tested the hypothesis that IMM uses wavelengths of visible blue/violet light as orientation cues that trigger phototactic responses. In four-choice laboratory experiments, blue light (400-475 nm) was significantly more effective than green (475-600 nm), orange (575-700 nm), or red (590-800 nm) light in attracting males and mated females. In subsequent experiments that tested light emitting diodes (LEDs) emitting peak wavelengths in the blue/violet-light range, the 405-nm 'violet' LED was significantly more effective than the 435-, 450-, or 470-nm 'blue' LED in attracting males as well as virgin and mated females. In electroretinogram recordings, the 405-nm wavelength elicited significantly stronger receptor potentials from female and male eyes than the 350-nm (UV) wavelength, and in a behavioral experiment it significantly enhanced the known attractiveness of UV light. Equal attraction of IMMs to 405-nm LEDs at 600-700 mu W/cm(2) with or without UV light, and significantly stronger attraction to a 405-nm LED than to a 350-nm LED at maximum light intensities, suggest that the deployment of violet instead of UV light could become one of several management tactics for control of IMMs. DOI
126.Gries, R; Schaefer, PW; Gotoh, T; Takacs, S; Gries, G. (2009) Spacing of traps baited with species-specific Lymantria pheromones to prevent interference by antagonistic components.Canadian Entomologist 141: 145-152 Spacing of traps baited with species-specific Lymantria pheromones to prevent interference by antagonistic components
GYPSY-MOTH LEPIDOPTERA; SEX-PHEROMONE; NUN MOTH; MONACHA; COMMUNICATION; INITIATION; INHIBITOR; MATHURA; DISPAR; JAPAN
In pheromone-based surveys for detecting multiple species of exotic lymantriine moths (Lepidoptera: Noctuidae: Lymantriinae), spacing between traps baited with species-specific pheromone lures must be sufficient to prevent antagonistic effects of heterospecific pheromone on lure attractiveness. Conducting field experiments with the Japanese gypsy moth, Lymantria dispar japonica Motschulsky,in northern Honshu, Japan, we first determined which congeneric pheromone components have strong antagonistic effects on attraction of male moths to the conspecific pheromone (7R,8S)-cis-7,8-epoxy-2-methyloctadecane ((+)-disparture). Since the most antagonistic compounds were pheromone/volatile components from the sympatric nun moth L. monacha (L.), we then conducted experiments with paired traps baited with either a L. dispar (L.) pheromone lure ((+)-disparlure (50 mu g)) or L. monacha pheromone lure (a mixture of (7R,8S)-cis-7,8-deoxyoctadecane ((+)-monachalure (50 mu g)), (7Z)-2-methyloctadecene (5 mu g), and (+)-disparture (50 mu g). As spacing between paired traps increased (0, 0.5, 2, 7.5, 15, or 30 m), the antagonistic effect of the L. monacha on the attractiveness of the L. dispar lure decreased and disappeared. For pheromone-based detection surveys of multiple species of exotic lymantriine moths in North America to lie effective, trap spacing of 15 m is recommended. DOI
125.Gries, R; Schaefer, PW; Nakamura, K; Gries, G. (2009) Lymantria dispar sex pheromone is a behavioral antagonist to pheromonal attraction of male Lymantria mathura.Canadian Entomologist 141: 53-55 Lymantria dispar sex pheromone is a behavioral antagonist to pheromonal attraction of male Lymantria mathura
MOTH LEPIDOPTERA-LYMANTRIIDAE; GYPSY-MOTH; IDENTIFICATION; ENANTIOMERS; COMPONENTS
In a trapping Study conducted in the experimental research forest of the Tohoku Research Center, Morioka, Honshu, Japan, we investigated the effect of heterospecific pheromone oil pheromonal attraction of male Japanese gypsy moth, Lymantria dispar japanica (Motschulsky), and male pink gypsy moth, L. mathura Moore (Lepidoptera: Noctuidae: Lymantriinae). Traps baited with synthetic pheromone of L. d. japonica ((7R,8S)-cis-7,8-epoxy-2-methyloctadecane = (+)-disparlure (100 mu g)) or L. mathura ((9R, 10S, 3Z, 6Z)-cis-9, 10-epoxynonadecadiene = (+)mathuralure (20 mu g) and (9R, 10S, 3Z, 6Z)-cis-9, 10-epoxynonadecadiene = (-)-mathuralure (80 mu g)) attracted male L. d. japonica or L. mathura, respectively. Traps baited with synthetic pheromone of both species captured significantly fewer male L. mathura than traps baited solely with synthetic L. mathura pheromone. Numbers of male L. d. japonica Captured in traps baited with (+)-disparlure were unaffected by the addition of L. mathura pheromone. (+)-Disparlure is a behavioral antagonist to pheromonal attraction of male L. mathura, whereas male L. d. japonica are indifferent to the presence of synthetic L. mathura pheromone. DOI
124. Jumean, Z; Fazel, L; Wood, C; Cowan, T; Evenden, ML; Gries, G. (2009) Cocoon-spinning larvae of Oriental fruit moth and Indianmeal moth do not produce aggregation pheromone.Agricultural and Forest Entomology 11: 205-212 Cocoon-spinning larvae of Oriental fruit moth and Indianmeal moth do not produce aggregation pheromone
MANDIBULAR GLAND SECRETION; BEETLE DENDROCTONUS-MICANS; PLODIA-INTERPUNCTELLA; CYDIA-POMONELLA; CODLING-MOTH; MEAL-MOTH; OLFACTORY RESPONSE; STORED PRODUCTS; LEPIDOPTERA; BEHAVIOR
1 Mature larvae of the Oriental fruit moth (OFM) Grapholita molesta (Lepidoptera: Tortricidae) and the Indianmeal moth (IMM) Plodia interpunctella (Lepidoptera: Pyralidae) leave their food source in search of suitable pupation sites in which to spin cocoons. These sites are typically well-concealed cracks and crevices within the environment. Such cocooning behaviour is also observed in larvae of the codling moth (CM) Cydia pomonella (Lepidoptera: Tortricidae), which aggregate prior to pupation in response to a pheromone blend produced by cocoon-spinning conspecific larvae. 2 In laboratory experiments, we tested whether cocoon-spinning OFM and IMM larvae produce aggregation pheromones and whether CM larvae are cross-attracted to closely-related OFM larvae. 3 Fifth-instar OFM and IMM larvae were not attracted to, or arrested by, cocoon-spinning conspecifics. Moreover, fifth-instar CM larvae were not cross-attracted to either cocoon-spinning OFM or IMM larvae. 4 Analyses of volatiles released from cocoon-spinning OFM and IMM larvae revealed that both OFM and IMM lack components that are present in the aggregation pheromone of CM larvae. This information may help explain why CM larvae are not cross-attracted to cocooning OFM or IMM larvae. DOI
123. Jumean, Z; Jones, E; Gries, G. (2009) Does aggregation behavior of codling moth larvae, Cydia pomonella, increase the risk of parasitism by Mastrus ridibundus?Biological Control 49: 254-258 Does aggregation behavior of codling moth larvae, Cydia pomonella, increase the risk of parasitism by Mastrus ridibundus?
HOST SELECTION; PHEROMONE; LOCATE; SIZE; EGGS
Mastrus ridibundus is a specialist hymenopteran parasitoid that parasitizes last-instar larvae or prepupae of the codling moth, Cydia pomonella. Foraging females eavesdrop on an aggregation pheromone produced by cocooning larvae. We investigated whether larvae that cocoon in aggregation experience a greater rate of parasitism than larvae that cocoon in isolation. In wind tunnel experiments, 10 larvae in aggregations were more readily located by female M. ridibundus than 10 larvae well separated from each other. Similarly, aggregations of 30 larvae were more attractive to female M. ridibundus than those of 3 larvae. In cage experiments, larval cocooning in aggregation or isolation had no effect on the mean rate of parasitism and the mean number of eggs deposited per parasitized host. In Petri-dish experiments, the location of larvae within an aggregation significantly affected their rate of parasitism, with those in the center of an aggregation completely shielded from parasitism. Our data suggest that aggregation behavior by C pomonella larvae does not appear to increase the rate of parasitism. The increased risk of aggregated larvae to be detected by M. ridibundus is likely offset by diluted parasitism risk and structural refugia effects that larvae in aggregation experience. As an egg-limited parasitoid, female M. ridibundus can parasitize on average only one larva in an aggregation, with the likelihood of parasitism for each larva being inversely proportional to the number of larvae in that aggregation. (C) 2009 Elsevier Inc. All rights reserved. DOI
122. Jumean, Z; Wood, C; Gries, G. (2009) Frequency Distribution of Larval Codling Moth, Cydia pomonella L., Aggregations on Trees in Unmanaged Apple Orchards of the Pacific Northwest.Environmental Entomology 38: 1395-1399 Frequency Distribution of Larval Codling Moth, Cydia pomonella L., Aggregations on Trees in Unmanaged Apple Orchards of the Pacific Northwest
INSECT PEST-CONTROL; PLODIA-INTERPUNCTELLA; MASTRUS-RIDIBUNDUS; MATING DISRUPTION; PHEROMONE; BEHAVIOR
The codling moth, Cydia pomonella L. (Lepidoptera: Tortricidae), is a key pest of pome fruits in North America. After locating a pupation site, larvae spin a cocoon from which aggregation pheromone disseminates that attracts conspecific larvae. In two unmanaged apple orchards in Wenatchee and Yakima, Washington State, we systematically surveyed cracks and crevices of tree trunks for cocooning C. pomonella larvae. Aggregates of larvae were found significantly more often than solitary larvae. The number of cocooning larvae in aggregates (=group size) was inversely correlated with the frequency occurrence of that group size. Group size ranged between 2 and 20 cocoons. Height above ground had no effect on location of aggregates. In orchard 1, the cardinal direction of the tree trunk had no effect on location of aggregations, but in orchard 2, aggregations were located significantly most often on the south side of trunks. The mean ratio of males and females in aggregations was 1.08:1 and 1.04:1 in orchards I and 2, respectively. Moreover, the number of males in aggregates did not significantly differ from that of females. Our data support the conclusion that larvae seek pupation sites not by chance but in large part in response to pheromone signal and microhabitat cues. The probability of aggregates forming is likely proportional to the population density of C. pamonella.
121. Lam, K; Geisreiter, C; Gries, G. (2009) Ovipositing female house flies provision offspring larvae with bacterial food.Entomologia Experimentalis et Applicata 133: 292-295 Ovipositing female house flies provision offspring larvae with bacterial food
DROSOPHILA; DIPTERA; CULICIDAE; BEHAVIOR
Symbiotic bacteria on house fly eggs, Musca domestica L. (Diptera: Muscidae), provide ovipositional cues for conspecific female flies and curtail the growth of fungi that compete with fly larval offspring for resources. Because bacteria are also essential dietary constituents for developing larvae, we tested the hypothesis that egg-derived bacteria support development of larvae to adults. From house fly eggs, we isolated and identified 12 strains of bacteria, eight and four of which were previously shown to induce and inhibit oviposition, respectively. When larvae were provisioned with a total dose of 106-107 colony-forming units of bacteria from either the oviposition-inducing or inhibiting group, or from both groups together, significantly more larvae completed development. Thus, egg-associated bacteria could be a fail-safe mechanism that ensures a bacterial food supply for larval offspring, particularly if the resource selected by parent females is poor in bacterial food. DOI
120. Lam, K; Thu, K; Tsang, M; Moore, M; Gries, G. (2009) Bacteria on housefly eggs, Musca domestica, suppress fungal growth in chicken manure through nutrient depletion or antifungal metabolites.Naturwissenschaften 96: 1127-1132 Bacteria on housefly eggs, Musca domestica, suppress fungal growth in chicken manure through nutrient depletion or antifungal metabolites
DROSOPHILA; LARVAE; COMPETITION; SYMBIONTS; DIPTERA; FLIES; PLANT; FLY
Female houseflies, Musca domestica (Diptera: Muscidae), lay their eggs in ephemeral resources such as animal manure. Hatching larvae compete for essential nutrients with fungi that also colonize such resources. Both the well-known antagonistic relationship between bacteria and fungi and the consistent presence of the bacterium Klebsiella oxytoca on housefly eggs led us to hypothesize (1) that K. oxytoca, and possibly other bacteria on housefly eggs, help curtail the growth of fungal resource competitors and (2) that such fungi indeed adversely affect the development of housefly larvae. Bacteria washed from housefly eggs significantly reduced the growth of fungi in chicken manure. Nineteen bacterial strains and ten fungal strains were isolated from housefly eggs or chicken manure, respectively. Co-culturing each of all the possible bacterium-fungus pairs revealed that the bacteria as a group, but no single bacterium, significantly suppressed the growth of all fungal strains tested. The bacteria's adverse effect on fungi is due to resource nutrient depletion and/or the release of antifungal chemicals. Well-established fungi in resources significantly reduced the number of larval offspring that completed development to adult flies. DOI
119. Mowat, J; Gries, R; Khaskin, G; Gries, G; Britton, R. (2009) (S)-2-Pentyl (R)-3-Hydroxyhexanoate, a Banana Volatile and Its Olfactory Recognition by the Common Fruit Fly, Drosophila melanogaster.Journal of Natural Products 72: 772-776 (S)-2-Pentyl (R)-3-Hydroxyhexanoate, a Banana Volatile and Its Olfactory Recognition by the Common Fruit Fly, Drosophila melanogaster
SEX-PHEROMONE; CULTIVARS; MIDGE; ACIDS; BUG
The volatile organic compounds emitted from ripening bananas that elicit an antennal response from the common fruit fly, Drosophila melanogaster, were analyzed by a combination of gas chromatographic-electroantennographic detection, mass spectrometry, and H-1 NMR spectroscopy. These analyses revealed that the headspace of ripening bananas contains a number of EAD-active components including the new ester (S)-2-pentyl (R)-3-hydroxyhexanoate, the structural assignment of which was confirmed by chemical synthesis. DOI PubMed
118. Schwarz, J; Gries, R; Hillier, K; Vickers, N; Gries, G. (2009) Phenology of Semiochemical-Mediated Host Foraging by the Western Boxelder Bug, Boisea rubrolineata, an Aposematic Seed Predator.Journal of Chemical Ecology 35: 58-70 Phenology of Semiochemical-Mediated Host Foraging by the Western Boxelder Bug, Boisea rubrolineata, an Aposematic Seed Predator
SCENTLESS PLANT BUGS; CEUTORHYNCHUS-ASSIMILIS; EXOCRINE SECRETIONS; SPECIES HEMIPTERA; OILSEED RAPE; RHOPALIDAE; HETEROPTERA; RESPONSES; ECOLOGY; JADERA
The western boxelder bug (BEB), Boisea rubrolineata (Heteroptera: Rhopalidae), is a specialist herbivore of boxelder trees, Acer negundo. We tested the hypothesis that BEBs use semiochemicals to locate host trees. Headspace volatiles from trees bearing staminate inflorescences ("staminate trees") and from trees bearing pistillate inflorescences ("pistillate trees") were collected throughout the season and bioassayed in Y-tube olfactometer experiments. Headspace extracts of early-season, pollen-bearing staminate trees and midseason pistillate trees with mature samaras (seed pods) attracted female and male BEBs. By using coupled gas chromatographic-electroantennographic detection and gas chromatography-mass spectrometry, we identified and tested a five-component synthetic blend of candidate semiochemicals (hexanol, pentyl acetate, phenylacetonitrile, 2-phenethyl acetate, and trans-nerolidol). This blend attracted females, males, and fifth-instar nymphs. Phenylacetonitrile by itself was as attractive as the five-component blend to both adults and nymphs. By responding to phenylacetonitrile emitted by pollen-bearing staminate trees and pistillate trees with maturing seeds, BEBs appear to track and exploit the availability of nutrient-rich food sources, suggesting that the bugs' reproductive ecology is synchronized to the phenology of their host boxelder tree. DOI
116. Takacs, S; Bottomley, H; Andreller, I; Zaradnik, T; Schwarz, J; Bennett, R; Strong, W; Gries, G. (2009) Infrared radiation from hot cones on cool conifers attracts seed-feeding insects.Proceedings of the Royal Society B-Biological Sciences 276: 649-655 Infrared radiation from hot cones on cool conifers attracts seed-feeding insects
infrared receptor; infrared radiation; Leptoglossus occidentalis; foraging cue; conifer cones; seed feeding COLOR-VISION; POLLINATION; RECEPTORS; HEAT; ANGIOSPERMS; HEMIPTERA; COREIDAE; FLOWERS; BIOLOGY; BEETLE
Foraging animals use diverse cues to locate resources. Common foraging cues have visual, auditory, olfactory, tactile or gustatory characteristics. Here, we show a foraging herbivore using infrared (IR) radiation from living plants as a host-finding cue. We present data revealing that (i) conifer cones are warmer and emit more near-, mid- and long-range IR radiation than needles, (ii) cone-feeding western conifer seed bugs, Leptoglossus occidentalis (Hemiptera: Coreidae), possess IR receptive organs and orient towards experimental IR cues, and (iii) occlusion of the insects' IR receptors impairs IR perception. The conifers' cost of attracting cone-feeding insects may be offset by occasional mast seeding resulting in cone crops too large to be effectively exploited by herbivores.PDF DOI
115. Evenden, ML; Gries, R; Gries, G. (2008) Attractiveness and toxicity of an attracticide formulation on adult males of ash leaf cone roller, Caloptilia fraxinella.Entomologia Experimentalis et Applicata 127: 30-38 Attractiveness and toxicity of an attracticide formulation on adult males of ash leaf cone roller, Caloptilia fraxinella
pheromone; attract and kill; lure and kill; permethrin; Lepidoptera; Gracillariidae; leg autotomy
A biodegradable attracticide formulation containing the pyrethroid insecticide permethrin and the sex pheromone of the ash leaf cone roller, Caloptilia fraxinella (Ely) (Lepidoptera: Gracillariidae), was tested for attractiveness and toxicity to males of this invasive pest of horticultural ash, Fraxinus spp. Marsh. (Oleaceae). Trap capture in attracticide-baited traps was equal to capture in traps baited with rubber septa lures releasing the known attractive pheromone. Pheromone response by male C. fraxinella was not affected by the presence of permethrin as equal numbers of males were captured in traps baited with the attracticide formulation with and without permethrin. Attraction to the attracticide containing both pheromone and insecticide active ingredients did not vary with dose as 10, 50, and 100 mg droplets of the formulation attracted similar numbers of male moths in a field experiment. Equal numbers of male moths were captured in traps baited with droplets that had aged for 0-5 weeks in a laboratory fume hood before deployment in the field. The permethrin constituent of the attracticide formulation was toxic to male moths treated through tarsal contact and resulted in 73 and 100% mortality at 24 and 72 h post-treatment, respectively. Leg autotomy occurred in over 80% of males 24 h post-treatment to formulations containing permethrin. Mortality of moths was greater 24 h after treatment with a fresh attracticide source as compared to a 5-week-old source. However, mortality as a result of treatment with fresh and aged attracticide droplets was equal at 48, 72, and 96 h post-treatment. This formulation has the potential to become a useful tool in an integrated pest-management system for C. fraxinella on horticultural ash. DOI
114. Hehar, G; Gries, R; Gries, G. (2008) Re-analysis of pheromone-mediated aggregation behaviour of European earwigs.Canadian Entomologist 140: 674-681 Re-analysis of pheromone-mediated aggregation behaviour of European earwigs
Aggregation of the European earwig, Forficula auricularia L. (Dermaptera: Forficulidae), is known to be, in part, a response to aggregation pheromone. However, many aspects of pheromone biology remain unknown or controversial. In two-choice experiments with field-collected specimens in a still-air olfactometer, we determined that female, male, and juvenile F auricularia all produce and respond to aggregation pheromone and that the pheromone is perceived by means of olfaction. Various sources (or extracts thereof) reportedly containing or emitting pheromone (including the insects' integument, tibiae, or fecal excreta) did not induce significant responses. Our data suggest that none of these sources contains all or any of the essential pheromone components. These controversial results may be due to differences in (i) experimental procedures, such as single- or grouped-insect bioassays, or (ii) developmental stages of the bioassay insects. It is conceivable that juveniles and adults produce and respond to different components of aggregation pheromone. DOI
113. Jumean, Z; Wood, C; Gries, G. (2008) Does larval aggregation pheromone of codling moth, Cydia pomonella, induce attraction or arrestment of receivers?Bulletin of Entomological Research 98: 425-429 Does larval aggregation pheromone of codling moth, Cydia pomonella, induce attraction or arrestment of receivers?
codling moth; Cydia pomonella; aggregation; pheromone; attract; arrest
Cocoon-spinning larvae of the codling moth, Cydia pomonella, emit a pheromone that mediates aggregation by pupation site-seeking fifth-instar larvae. It was unknown and, thus, we tested whether the aggregation pheromone induces arrestment or attraction responses. In paired straight-tube experiment 1, fifth-instars moved faster and farther upwind toward cospecific cocoons compared to blank controls. In still-air cage experiment 2, fifth-instars selected more often as first and final choices of pupation sites those with cocooning conspecifics than those without. Finally, in Y-tube olfactometer experiment 3, fifth-instars anemotactically responded to, and preferred, side arms with cocooning conspecifics to those without. Our data provide evidence that codling moth larvae are attracted to, rather than merely arrested by, larval aggregation pheromone. These results help explain reported aggregations or clumped distributions of larvae on tree trunks, which would likely not occur if they were based merely on chance encounter of cocoon-spinning larvae by foraging larvae. DOI
112. Paduraru, PA; Popoff, RTW; Nair, R; Gries, R; Gries, G; Plettner, E. (2008) Synthesis of substituted alkoxy benzene minilibraries, for the discovery of new insect olfaction or gustation inhibitors.Journal of Combinatorial Chemistry 10: 123-134 Synthesis of substituted alkoxy benzene minilibraries, for the discovery of new insect olfaction or gustation inhibitors
We describe methods for the rapid generation of minilibraries of substituted alkoxy benzenes (consisting of 4-5 compounds), for screening as insect olfaction or gustation inhibitors. Synthetic or commercially available monoalkoxy benzene compounds were mixed and reacted with various alkyl halides to afford a first set of minilibraries. A second and third set were generated from allyloxy minilibraries. via the Claisen rearrangement and subsequent alkylation of the ortho-allyl phenols. We have chosen to prepare a collection of small libraries (as opposed to one large library) to test the response insects exhibit toward blends of compounds. We demonstrate how our minilibraries can be screened, both against insect antennae and against expressed pheromone-binding proteins from the gypsy moth, Lymantria dispar. DOI PubMed
111. Sidney, M; Brown, K; Judd, GJR; Gries, G. (2008) Stimuli affecting selection of oviposition sites by female peach twig borer, Anarsia lineatella Zeller (Lepidoptera : Gelechiidae).Journal of Applied Entomology 132: 538-544 Stimuli affecting selection of oviposition sites by female peach twig borer, Anarsia lineatella Zeller (Lepidoptera : Gelechiidae)
host selection; host suitability; semiochemicals; tactile cues
In laboratory and field experiments, stimuli were tested that might affect oviposition decisions by female peach twig borer moths, Anarsia lineatella Zeller (Lepidoptera: Gelechiidae). When given a choice between immature green peach fruits, green mature peach fruits and soft-ripe peach fruits, the latter received the fewest eggs. Fuzzy halves of peach fruits received ten times more eggs then shaved hairless halves. Volatiles from both almond and peach shoots induced more oviposition by females than by control stimuli. Similarly, volatiles from immature green peach fruits, mature green or mature hard-ripe peach fruits induced more oviposition than their respective control stimuli. In a choice experiment, volatiles from immature peach fruit stimulated three times more oviposition than those from soft-ripe peach fruit. Discrimination against mature soft-ripe peach fruits as potential oviposition sites may lie in the phenology of A. lineatella and host peach fruits. Larval development to the pupal stage takes 15-27 days. Therefore, any eggs laid on a ripe fruit 14 days before it falls from the tree will not likely develop into adult insects because developing larvae will only reach third or fourth instar before the fruit is decomposed, and only first and second instar larvae can overwinter. DOI
110. Siljander, E; Gries, R; Khaskin, G; Gries, G. (2008) Identification of the airborne aggregation pheromone of the common bed bug, Cimex lectularius.Journal of Chemical Ecology 34: 708-718 Identification of the airborne aggregation pheromone of the common bed bug, Cimex lectularius
Cimex lectularius; Cimicidae; bed bug; aggregation pheromone; octanal; nonanal; decanal; (E)-2-hexenal; (E)-2-octenal; (2E,4E)-octadienal; (2E,4Z)-octadienal; benzaldehyde; benzyl acetate; benzyl alcohol; limonene; sulcatone; geranylacetone
Adults and juveniles of the common bed bug, Cimex lectularius L. (Hemiptera: Cimicidae), return to and aggregate in harborages after foraging for hosts. We tested the hypothesis that the aggregation is mediated, in part, by an airborne aggregation pheromone. Volatiles from experimental C. lectularius harborages were captured on Porapak Q, fractionated by liquid chromatography, and bioassayed in dual-choice, still-air olfactometer experiments. Of 14 compounds with > 100 pg abundance in gas chromatography-mass spectrometry analyses of two bioactive fractions, 10 compounds [nonanal, decanal, (E)-2-hexenal, (E)-2-octenal, (2E,4E)-octadienal, benzaldehyde, (+)- and (-)-limonene, sulcatone, benzyl alcohol] proved to be essential components of the C. lectularius airborne aggregation pheromone. DOI
109. Takacs, S; Hardin, K; Gries, G; Strong, W; Bennett, R. (2008) Vibratory communication signal produced by male western conifer seed bugs. (Hemiptera : Coreidae).Canadian Entomologist 140: 174-183 Vibratory communication signal produced by male western conifer seed bugs. (Hemiptera : Coreidae)
We tested the hypothesis that the western conifer seed bug, Leptoglossus occidentalis Heidemann, uses a substrate-borne vibratory signal for short-range communication. To record such a signal we used computers equipped with data-acquisition hardware and software, microphones sensitive to sonic and (or) ultrasonic frequencies, membrane-type and piezoelectric speakers capable of emitting sonic and ultrasonic sound, and piezoelectric devices capable of emitting low-level, low-frequency vibrations. By tapping their abdomen on substrate, males produced a wide-band vibratory signal 20 dB (sound pressure level; 0 dB = 20 mu Pa) above ambient sound, with dominant frequencies of 115 +/- 10 and 175 +/- 15 Hz and a distinct temporal pattern. There was no evidence for (i) ultrasonic signal components; (ii) signals produced by females or nymphs, or (iii) repeated trains of signal pulses. In two-choice arena experiments, males and females preferred the playedback recording of the male-produced substrate-borne signal over silent controls, whereas nymphs showed no preference for either stimulus. In two-choice dowel experiments with hickory wood or lodgepole pine crossbeams, females (unlike males or nymphs) preferred played-back recordings of the same signal over controls. In two-choice field experiments, this signal emitted in the air by piezoelectric devices or transferred through a wire to lodgepole pine branches attracted more L. occidentalis than did silent controls. Our data support the hypothesis that L. occidentalis uses a substrate-borne vibratory signal for short-range communication. The use of such a signal is consistent with reports on communication by other true bug species.
108. Wijenberg, R; Takacs, S; Cook, M; Gries, G. (2008) Female German cockroaches join conspecific groups based on the incidence of auditory cues.Entomologia Experimentalis et Applicata 129: 124-131 Female German cockroaches join conspecific groups based on the incidence of auditory cues
auditory stimulus; decision making; joining cues; joining behaviour; group size; Blattella germanica; Dictyoptera; Blattellidae
Insects deciding whether to approach and join a group of conspecifics may utilize olfactory and auditory signals, or cues, from that group as indicators of its size or the suitability of its shelter. Here we show (1) that German cockroaches, Blattella germanica L. (Dictyoptera: Blattellidae), in groups wing-fan; (2) that the incidence of wing-fanning (WF) increases proportionately to group size; and (3) that gravid females utilize auditory cues associated with WF behaviour when they decide whether or not to enter a shelter. In binary choice arena bioassays, proportionately more gravid females avoided shelters associated with play-back of high-incidence male- or female-produced WF sound, indicating a high-density group of conspecifics, but sought shelters associated with play-back of low-incidence WF sound, indicating a low-density group of conspecifics. These auditory cues seem to convey information on group size or density, avoid sensory fatigue in enclosed environments, and allow sonotactic orientation to the group's location. DOI
107. Woodbury, N; Gries, G. (2008) Amber-colored excreta: a source of arrestment pheromone in firebrats, Thermobia domestica.Entomologia Experimentalis et Applicata 127: 100-107 Amber-colored excreta: a source of arrestment pheromone in firebrats, Thermobia domestica
frass; feces; gregarine; exuviae; silk; aggregation; assembly; harbourage; Thysanura; Zygentoma; Lepismatidae
Female, male, and juvenile firebrats, Thermobia domestica (Packard) (Thysanura: Lepismatidae), employ a pheromone that arrests conspecifics on contact. Paper shelters placed in a T. domestica colony accumulate fecal excreta (= frass) and other insect-derived debris. Such shelters elicit arrestment by conspecifics. However, the definitive source of the arrestment pheromone was not known. We tested the hypothesis that one or more debris components from a T. domestica shelter constitute the source of the arrestment pheromone. In dual-choice, still-air olfactometer experiments, scales, exuviae, antennae, caudal filaments, gregarine parasite cysts, and silk (each intact or macerated) retrieved from shelters and separated for experiments, as well as saliva, hemolymph, and fat body extracted from insects all failed to arrest female T. domestica. Similarly, paper that had been fed upon by insects did not elicit an arrestment response, eliminating insect-altered cellulose as the arrestant pheromone. In contrast, insect-exposed glass significantly arrested females. Moreover, females were significantly arrested by (i) loose, insect-derived debris brushed from shelters, (ii) a frass mixture manually separated from loose debris, and (iii) specific amber-type frass manually separated from the frass mixture. These results lead us to conclude that amber-type frass constitutes the source of at least part of the T. domestica arrestment pheromone. DOI
106. Derksen, S; Chatterton, M; Gries, R; Aurelian, M; Judd, GJR; Gries, G. (2007) Semiochemical-mediated oviposition behavior by female peachtree borer, Synanthedon exitiosa.Entomologia Experimentalis et Applicata 123: 101-108 Semiochemical-mediated oviposition behavior by female peachtree borer, Synanthedon exitiosa
Lepidoptera; Sesiidae; host selection; host suitability; frass
The peachtree borer, Synanthedon exitiosa (Say) (Lepidoptera: Sesiidae), is an important pest of commercial cultivations of peach trees, Prunus persicae (L.) (Rosaceae). Identification of semiochemicals that mediate host selection by adult S. exitiosa may lead to the development of a new earth-friendly tactic within integrated programs for control of S. exitiosa. Larvae develop in the phloem of peach trees where their feeding stimulates the production of gum frass, a mixture of tree phloem particles, tree sap (gum), and larval feces (frass). We tested the hypothesis that gum-frass semiochemicals signal a potential host tree, and induce oviposition by female S. exitiosa. In coupled gas chromatographic-electroantennographic detection analyses of Porapak Q-collected gum frass volatiles, 21 compounds elicited responses from male or female S. exitiosa antennae. These compounds included four acids, four hydrocarbons, four ketones, three acetates, two aldehydes, gamma-decalactone, conophthorin, 2-phenylethanol, and 2-isopropyl-3-methoxypyrazine. In dual-choice laboratory experiments, all groups of compounds, except the acetates, were needed to induce significantly more egg laying by female S. exitiosa on treatment than on unbaited control oviposition sites. By responding to gum frass semiochemicals, female S. exitiosa seem to exploit signals that are complex, detectable, and that reliably indicate a potential host tree for larval development. DOI
105.Gries, R; Bennett, RG; Khaskin, G; Gries, G. (2007) Attraction of male Mayetiola thujae (Diptera : Cecidomyiidae) to the sex-pheromone blend of (2S,12S)-, (2S,13S)-, and (2S,14S)-diacetoxyheptadecane is reduced in the presence of the SR- or RR-stereoisomers.Canadian Entomologist 139: 685-689 Attraction of male Mayetiola thujae (Diptera : Cecidomyiidae) to the sex-pheromone blend of (2S,12S)-, (2S,13S)-, and (2S,14S)-diacetoxyheptadecane is reduced in the presence of the SR- or RR-stereoisomers
In a field trapping experiment in an abandoned seed orchard of western red-cedar, Thuja plicata Donn x D. Don, in British Columbia, we show that attraction of male red-cedar cone midges, Mayetiola thujae (Hedlin), to the pheromone blend (2S,12S)-, (2S,13S)-, and (2S, 14S)-diacetoxyheptadecane is reduced in the presence of a blend of all other stereoisomers, or of the three SR- or RR-stereoisomers. The three RS-stereoisomers, in contrast, had no significant effect. Thus, synthetic pheromone for monitoring M. thujae populations must not contain the SR- or RR-stereoisomers of 2,12-, 2,13-, and 2,14-diacetoxyheptadecane. This result will allow development of a less expensive design for synthesizing the pheromone.
103.Gries, R; Schaefer, PW; Hahn, R; Khaskin, G; Ramaseshiah, G; Singh, B; Hehar, GK; Gries, G. (2007) Sex pheromone components of indian gypsy moth, Lymantria obfuscata.Journal of Chemical Ecology 33: 1774-1786 Sex pheromone components of indian gypsy moth, Lymantria obfuscata
Indian gypsy moth; Lymantria obfuscata; Lymantria dispar; (+)-disparlure; (-)-disparlure; (Z)-2-methyloctadec-7-ene; (3R,7Z)-3-methylnonadec-7-ene; (3S,7Z)-3-methylnonadec-7-ene; (3R,7R,8S)-cis-7,8-epoxy-3-methylnonadecane; (3S,7R,8S)-cis-7,8-epoxy-3-methylnonadecane; sex pheromone; lepidoptera; lymantriidae
The Indian gypsy moth, Lymantria obfuscata (Lepidoptera: Lymantriidae), has been recognized as a distinct species since 1865 but closely resembles a diminutive form of gypsy moth, Lymantria dispar. We tested the hypothesis that the sex pheromones of L. obfuscata and L. dispar are similar. In laboratory mate acceptance studies, very few male L. dispar made copulatory attempts when paired with female L. obfuscata, suggesting that female L. obfuscata emit one or more pheromone components antagonistic to male L. dispar. In coupled gas chromatographic-electroantennographic detection (GC-EAD) analyses of pheromone gland extract of female L. obfuscata, (Z)-2-methyloctadec-7-ene (2Me-7Z-18Hy) and (7R,8S)-cis-7,8-epoxy-2-methyloctadecane [(+)-disparlure] were most abundant and elicited the strongest responses from male L. obfuscata antennae. In field experiments near Solan (Himachal Pradesh, India), 2Me-7Z-18Hy and (+)-disparlure in combination attracted more male L. obfuscata than did either component alone. This two-component sex pheromone contrasts with the single-component sex pheromone [(+)-disparlure] of L. dispar. The contrasting composition of the lymantriid communities inhabited by L. obfuscata and L. dispar may explain why 2Me-7Z-18Hy is a pheromone component in L. obfuscata and a pheromone antagonist in L. dispar and why (-)-disparlure reduces pheromonal attraction of male L. dispar but not male L. obfuscata. DOI
102. Jumean, Z; Lafontaine, JP; Wood, C; Judd, GJR; Gries, G. (2007) Pheromone-based trapping of larval codling moth, Cydia pomonella, in apple orchards.Entomologia Experimentalis et Applicata 122: 87-91 Pheromone-based trapping of larval codling moth, Cydia pomonella, in apple orchards
pheromone; larval aggregation; tree banding; integrated pest management; Lepidoptera; Tortricidae
Website DOI
101. Lam, K; Babor, D; Duthie, B; Babor, EM; Moore, M; Gries, G. (2007) Proliferating bacterial symbionts on house fly eggs affect oviposition behaviour of adult flies.Animal Behaviour 74: 81-92 Proliferating bacterial symbionts on house fly eggs affect oviposition behaviour of adult flies
bacterial symbiont; communication ecology; house fly; microhabitat management; Musca domestica; reproductive strategy; signalling
Animals commonly leave scent messages by depositing pheromones, faeces, or urine. The intensity of a chemical message may fade over time, but the 'intention' remains the same. We argue that house flies, Musca domestica (Diptera: Muscidae), require a message with evolving (sensu changing over time) information content. Gravid females reportedly deploy a pheromone that induces concerted oviposition so that many even-aged larvae ameliorate the resource, such as animal manure. However, continued oviposition by late-arriving females may result in age disparity and cannibalism of larval offspring. Thus, we predicted that house flies have a type of cue that evolves from oviposition induction to inhibition some time after eggs are deposited on a resource. Here we show (1) the existence of such evolving ovipositional cues, (2) the adverse fitness consequences that accrue from ignoring the inhibitory cues and (3) the mechanism by which these cues evolve. The evolving cues depend upon a key bacterial strain, Klebsiella oxytoca, which originates with female M. domestica and which proliferates over time on the surface of deposited eggs. At a threshold density of this strain, further oviposition is inhibited. By deploying such evolving cues, female M. domestica can visit an oviposition site just once and deposit cues that will mediate immediate oviposition induction followed by delayed inhibition, thereby ensuring conditions conducive for offspring development. (C) 2007 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved. DOI
100. Nosil, P; Crespi, BJ; Gries, R; Gries, G. (2007) Natural selection and divergence in mate preference during speciation.Genetica 129: 309-327 Natural selection and divergence in mate preference during speciation
speciation; hybrid fitness; mate choice; reproductive isolation; pheromones
Sexual isolation can evolve due to natural selection against hybrids (reinforcement). However, many different forms of hybrid dysfunction, and selective processes that do not involve hybrids, can contribute to the evolution of sexual isolation. Here we review how different selective processes affect the evolution of sexual isolation, describe approaches for distinguishing among them, and assess how they contribute to variation in sexual isolation among populations of Timema cristinae stick-insects. Pairs of allopatric populations of T. cristinae living on different host-plant species exhibit greater sexual isolation than those on the same host, indicating that some sexual isolation has evolved due to host adaptation. Sexual isolation is strongest in regions where populations on different hosts are in geographic contact, a pattern of reproductive character displacement that is indicative of reinforcement. Ecological costs to hybridization do occur but traits under ecological selection (predation) do not co-vary strongly with the probability of between-population mating such that selection on ecological traits is not predicted to produce a strong correlated evolutionary response in mate preference. Moreover, F1 hybrid egg inviability is lacking and the factors contributing to reproductive character displacement require further study. Finally, we show that sexual isolation involves, at least in part, olfactory communication. Our results illustrate how understanding of the evolution of sexual isolation can be enhanced by isolating the roles of diverse ecological and evolutionary processes. DOI
99. SCHAEFER, P; Naoto KAMATA, Nusyirwan HASAN, Gerhard GRIES, Regine GRIES, Idrus ABBAS, Siti SALMAH, Ahsol HASYIM. (2007) Synthetic Lymantriid Pheromones Attract Male Moths of Lymantria spp. (Lepidoptera: Lymantriidae) in Sumatra.Tropics 16: 71-74 Synthetic Lymantriid Pheromones Attract Male Moths of Lymantria spp. (Lepidoptera: Lymantriidae) in Sumatra
Pheromone components previously identified in various lymantriid moths were field tested in a trapping experiment near Padang, West Sumatra, Indonesia. Each of ten experimental replicates, consisting of four sticky traps, were deployed in complete randomized block and baited with one of four synthetic pheromone lures. Most interesting results include: (1) significant captures of male Lymantria brunneiplaga in traps baited with (+)- and (-)-xylinalure [(7R,8S)- and (7S,8R)-cis-7,8 epoxy-2-methyleicosane]; and (2) capture of male Lymantria subrosea singapura in traps baited with (+)-disparlure [(7R,8S)-cis-7,8-epoxy-2-methyloctadecane], (+)-monachalure [(7R,8S)-cis -7,8-epoxy-octadecane] and 2-methyl-Z 7-octadecene. These results will allow an improve pheromone-based monitoring of L. brunneiplagaand L. subrosea singapura, respectively. Future studies should attempt to obtain virgin female moths of respective species for thorough laboratory analyses and field testing of candidate pheromone components. Males of L. beatrix (2) and Lymantria narindra (1) also responded to (+)-disparlure baited traps.PDF
98. Siljander, E; Penman, D; Harlan, H; Gries, G. (2007) Evidence for male- and juvenile-specific contact pheromones of the common bed bug Cimex lectularius.Entomologia Experimentalis et Applicata 125: 215-219 Evidence for male- and juvenile-specific contact pheromones of the common bed bug Cimex lectularius
Heteroptera; Cimicidae; aggregation; arrestment; marker pheromones; communication; semiochemicals
Males and females of the common bed bug, Cimex lectularius L. (Heteroptera: Cimicidae), have been shown to produce and respond to an aggregation pheromone. We tested whether juvenile C. lectularius also produce and respond to aggregation pheromone, and whether the pheromone is perceived by contact chemoreception. In dual-choice laboratory experiments, juveniles, but not males or females, preferred juvenile-exposed paper discs to control discs. Unlike juveniles, males and females preferred male-exposed paper discs to control discs. Neither juveniles, males, nor females preferred female-exposed discs to control discs. When test stimuli were inaccessible, C. lectularius failed to show any preference. Male- and juvenile-specific contact pheromones may have contrasting functions of marking shelters as safe refugia for development and growth (juveniles) or mate encounter (adults), but result in the same phenomenon, the aggregation of conspecifics. DOI
97. Woodbury, N; Gries, G. (2007) Pheromone-based arrestment behavior in the common silverfish, Lepisma saccharina, and giant silverfish, Ctenolepisma longicaudata.Journal of Chemical Ecology 33: 1351-1358 Pheromone-based arrestment behavior in the common silverfish, Lepisma saccharina, and giant silverfish, Ctenolepisma longicaudata
Lepisma saccharina; Ctenolepisma longicaudata; Thermobia domestica; Thysanura; Zygentoma; Lepismatidae; contact pheromone; aggregation; arrestment
Aggregations of the common silverfish, Lepisma saccharina, and giant silverfish, Ctenolepisma longicaudata (both Thysanura: Lepismatidae), are mediated by species-specific pheromones. In dual-choice, still-air olfactometer experiments, filter paper previously exposed to 12 male, female, or juvenile L. saccharina or C. longicaudata arrested conspecifics regardless of developmental stage or sex. Arrestment responses required physical contact with the pheromone. Insect-derived frass, scales, antennae, and setae, as well as salivary gland content, are not the source of the contact pheromone in L. saccharina. Lepisma saccharina did not respond to the pheromone of C. longicaudata, nor to that of another thysanuran, the firebrat Thermobia domestica. However, C. longicaudata responded to pheromones of both L. saccharina and T. domestica, whereas T. domestica responded to the C. longicaudata but not L. saccharina pheromone. These results support the hypothesis that a closer phylogenetic relationship exists between C. longicaudata and T. domestica than between C. longicaudata and L. saccharina, but a definitive conclusion must await molecular genetic analyses of all three species. DOI
96. Broberg, CL; Borden, JH; Gries, R. (2006) Olfactory and feeding preferences of Cryptorhynchus lapathi among hosts and nonhosts.Canadian Entomologist 138: 357-366 Olfactory and feeding preferences of Cryptorhynchus lapathi among hosts and nonhosts
In British Columbia, native willows (Salix spp.) (Salicaceae) and, to a lesser extent, black cottonwood (Populus trichocarpa Torr. & Gray) (Salicaceae) are frequently attacked by the poplar and willow borer, Cryptorhynchus lapathi (L.) (Coleoptera: Curculionidae). Red alder (Alnus rubra Bong.) (Betulaceae), trembling aspen (Populus tremuloides Michx.), and bigleaf maple (Acer macrophyllum Pursh) (Aceraceae) are not attacked. We studied olfaction and feeding preferences in the laboratory and feeding, oviposition, and emergence in the field. Female C. lapathi preferred Scouler's willow (Salix scouleriana Barratt ex Hook.) over all other species by olfaction, but males did not discriminate between Scouler's willow and black cottonwood or trembling aspen. All species elicited at least some attraction in no-choice situations. Willow was generally preferred for feeding, but black cottonwood and red alder were also acceptable, unlike trembling aspen or bigleaf maple. In field caging experiments, adult weevils emerged from willow, black cottonwood, and red alder. We conclude that olfaction and feeding preferences are sufficiently powerful to mediate the frequent attack observed on native willows, the intermediate levels of attack on cottonwood, and the absence of attack on red alder. Successful development on red alder suggests that C. lapathi could expand its host range to include this species.
95. Danci, A; Gries, R; Schaefer, PW; Gries, G. (2006) Evidence for four-component close-range sex pheromone in the parasitic wasp Glyptapanteles flavicoxis.Journal of Chemical Ecology 32: 1539-1554 Evidence for four-component close-range sex pheromone in the parasitic wasp Glyptapanteles flavicoxis
Glyptapanteles flavicoxis; Lymantria dispar; hymenoptera; braconidae; parasitoid; close-range sex pheromone; wing fanning
Females of the parasitic wasp Glyptapanteles flavicoxis (Hymenoptera: Braconidae) deposit a close-range sex pheromone from their abdominal tip that attracts conspecific males and elicits wing-fanning behavior. In this study, we isolated the pheromone components and determined their role in the males' behavior. In coupled gas chromatographic-electroantennographic detection (GC-EAD) analyses of the females' body extract, four components (below GC detection) elicited strong responses from male antennae. Monitored by GC-EAD, the components were separated by flash silica gel and high-performance liquid chromatography. Y-tube olfactometer experiments with one or more components revealed that all are necessary to elicit short-range attraction and wing-fanning responses by males. These components remained below detection threshold of the mass spectrometer (similar to 10 pg) even when 4500 female equivalents were analyzed in a single injection, which attests to the potency of the pheromone and the insects' sensitivity to it.
94. Danci, A; Schaefer, PW; Schopf, A; Gries, G. (2006) Species-specific close-range sexual communication systems prevent cross-attraction in three species of Glyptapanteles parasitic wasps (Hymenoptera : Braconidae).Biol Control 39: 225-231 Species-specific close-range sexual communication systems prevent cross-attraction in three species of Glyptapanteles parasitic wasps (Hymenoptera : Braconidae)
Glyptapanteles flavicoxis; Glyptapanteles indiensis; Glyptapanteles liparidis; Lymantria dispar; hymenoptera; Braconidae; parasitoid; species-specificity; pheromone; close-range pheromonal communication
The braconid parasitoids Glyptapanteles indiensis (Marsh) and G. liparidis (Bouche) occur in sympatry and allopatry, respectively, with their congener G. flavicoxis (Marsh). We tested the hypothesis that all three parasitoids, but particularly sympatric G. indiensis and G. flavicoxis, use species-specific sex pheromone blends for close-range sexual communication. In coupled gas chromatographic-electro-antennographic detection (GC-EAD) analyses of body extracts of conspecific females, male G. indiensis antennae responded to five components, one of which is specific to G. indiensis, and four are in common with G. flavicoxis. Male G. liparidis antennae responded to six components, two of which are specific to G. liparidis, and four are in common with G. flavicoxis. In Y-tube olfactometer experiments, body extracts of females elicited close-range attraction and wing-fanning responses only by conspecific but not by heterospecific males, supporting the hypothesis of close-range species-specific sex pheromone blends. (c) 2006 Elsevier Inc. All rights reserved.
93.Gries, R; Khaskin, G; Daroogheh, H; Mart, C; Karadag, S; Er, MK; Britton, R; Gries, G. (2006) (2S,12Z)-2-acetoxy-12-heptadecene: Major sex pheromone component of pistachio twig borer, Kermania pistaciella.J. Chem. Ecol. 32: 2667-2677 (2S,12Z)-2-acetoxy-12-heptadecene: Major sex pheromone component of pistachio twig borer, Kermania pistaciella
pistachio twig borer; Kermania pistaciella; (2S, 12Z)-12-heptadecen-2-ol; (2R, 12Z)-12-heptadecen-2-ol; (2S,12Z)-2-acetoxy-12-heptadecene; (2R,12Z)-2-acetoxy-12-heptadecene; sex pheromone; secondary acetate
The sex pheromone of the pistachio twig borer, Kermania pistaciella (Lepidoptera: Oinophilidae), one of the most important insect pests of pistachio, Pistacia vera, in Turkey and Iran, was identified. In gas chromatographic-electroantennographic detection (GC-EAD) and GC-mass spectrometric analyses of pheromone gland extracts of female K. pistaciella from Turkey, (2S,12Z)-2-acetoxy-12-heptadecene was identified as the major candidate pheromone component. In field experiments in Turkey, lures containing synthetic (2S,12Z)-2-acetoxy-12-heptadecene attracted large numbers of male moths. Its attractiveness was significantly reduced by the presence of the R-enantiomer or of either enantiomer of the corresponding alcohol. (2S,12Z)-2-Acetoxy-12-heptadecene is the first pheromone component identified in the Oinophilidae and the first secondary acetate pheromone component identified in the Lepidoptera. DOI PubMed
92.Gries, R; Khaskin, G; Tan, ZX; Zhao, BG; King, GGS; Miroshnychenko, A; Lin, GQ; Rhainds, M; Gries, G. (2006) (1S)-1-ethyl-2-methylpropyl 3,13-dimethylpentadecanoate: Major sex pheromone component of Paulownia bagworm, Clania variegata.Journal of Chemical Ecology 32: 1673-1685 (1S)-1-ethyl-2-methylpropyl 3,13-dimethylpentadecanoate: Major sex pheromone component of Paulownia bagworm, Clania variegata
Paulownia bagworm; Clania variegata; Psychidae; sex pheromone; 1-ethyl-2-methylpropyl 3,13-dimethylpentadecanoate
The Paulownia bagworm, Clania variegata Snell. (Lepidoptera: Psychidae), is one of the most significant forest defoliators in China. In gas chromatographic (GC)-electroantennographic detection analyses of pheromone gland extracts of female C. variegata on three GC columns (DB-5, DB-23, DB-210), two compounds (A and B) elicited strong responses from male antennae. The more abundant component B was isolated by high-performance liquid chromatography and identified as 1-ethyl-2-methylpropyl 3,13-dimethylpentadecanoate by transesterification, GC-mass spectrometry (MS), and comparison of its spectral and GC retention characteristics with those of synthetic compounds. In field trapping experiments in China, racemic and (1S)-1-ethyl-2-methylpropyl 3,13-dimethylpentadecanoate [but not the (1R)-stereoisomer] attracted male C. variegata. The absolute configuration of B (a molecule with three chiral centers) and the structure of component A remain to be determined.
91. Schlamp, KK; Brown, K; Gries, R; Hart, M; Gries, G; Judd, GGR. (2006) Diel periodicity of sexual communication in Anarsia lineatella (Lepidoptera : Gelechiidae).Canadian Entomologist 138: 384-389 Diel periodicity of sexual communication in Anarsia lineatella (Lepidoptera : Gelechiidae)
The sex pheromone of the peach twig borer, Anarsia lineatella (Zeller), was identified 30 years ago but the communication biology of this species has hardly been studied. In laboratory experiments, female moths kept at a photoperiod of 16L:8D (20 +/- 2 degrees C, 70% +/- 5% relative humidity) emitted pheromone before, during, and after sunrise (0400-0600 Pacific standard time), whereas pheromone was present in pheromone glands at similar quantities throughout the 24 h recording period. These data suggest that pheromone production and emission are not closely linked. In field experiments during July 2001 near Livingston, California (CA), and during June 2002 near Keremeos, British Columbia (BC), males were attracted to traps baited with synthetic sex pheromone (CA) or conspecific females (BC) only between 0300 and 0600 (Pacific standard time), suggesting overlap between periods of pheromone emission by females and attraction response by males. Groups of females in the presence of conspecific males, which were physically separated from females, emitted less sex pheromone than groups of females in the absence of males, suggesting that males communicate their presence to females and females change their behaviour in response.
90. Sidney, M; Regine Gries, Adela Danci, Gary J. R. Judd, Gerhard Gries. (2006) Almond volatiles attract neonate larvae of Anarsia lineatella (Zeller) (Lepidoptera: Gelechiidae).Journal of the Entomological Society of British Columbia 103: 3-9 Almond volatiles attract neonate larvae of Anarsia lineatella (Zeller) (Lepidoptera: Gelechiidae)
semiochemicals; β-bourbonene; (EE)-α-farnesene; (E)-β-ocimene; nonanal; decanal; olfactometer bioassay
Post-diapause overwintered larvae and neonates of any generation of the peach twig borer, Anarsia lineatella (Zeller), seek suitable sites to bore into and mine tissue of their host plants, including almond and peach. We tested the hypothesis that larvae are attracted to the same almond volatiles that elicit antennal responses from adult moths. Of five candidate almond semiochemicals [β-bourbonene, (E,E)-α-farnesene, (E)-β-ocimene, nonanal, decenal] tested singly or in binary combination (nonanal, decenal) in laboratory Y-tube olfactometers, only β-bourbonene attracted neonate larvae. β-bourbonene in combination with (EE)-α-farnesene was as attractive as the complete almond volatile blend, indicating that they are key semiochemicals for foraging larvae.Website
89. Tremblay, MN; Gries, G. (2006) Abiotic and biotic factors affect microhabitat selection by the firebrat, Thermobia domestica (Packard) (Thysanura : Lepismatidae).J Insect Behav 19: 321-335 Abiotic and biotic factors affect microhabitat selection by the firebrat, Thermobia domestica (Packard) (Thysanura : Lepismatidae)
aggregation; temperature; shelter; oviposition; predation risk; Zygentoma
Arthropod microhabitat selection involves a hierarchical assessment of abiotic and biotic factors. In choice experiments, we tested firebrat, Thermobia domestica, microhabitat preferences. Firebrats preferred elevated (35 degrees C) over ambient (20 degrees C) temperature, black over white shelter, and small (1 cm) over large (15.5 cm) entrance holes. Food availability did not alter shelter selection by firebrats. Medium juveniles, large juveniles and adults, in homo- and heterogeneous populations, preferred high (4.5 and 6.0 mm) over low (1.5 and 3.0 mm) shelter heights. Small juveniles, however, selected shelters with conspecifics, not by size. Females held at 35 degrees C, but not 20 or 25 degrees C, laid large numbers of eggs. Thus, abiotic characteristics of a shelter, coupled with the presence of conspecifics, affect microhabitat selection by firebrats. These findings may improve entrapment and management systems of firebrats.
87. Broberg, CL; Borden, JH; Gries, R. (2005) Olfactory and feeding preferences of Cryptorhynchus lapathi L. (Coleoptera : Curculionidae) among hybrid clones and natural poplars.Environ Entomol 34: 1606-1613 Olfactory and feeding preferences of Cryptorhynchus lapathi L. (Coleoptera : Curculionidae) among hybrid clones and natural poplars
hybrid poplar; Cryptorhynchus lapathi; resistance; Populus maximowiczii; host selection
Hybrid poplar clones show varying levels of attack by Cryptorhynchus lapathi (L.), a wood-boring weevil. We studied differences in olfactory and feeding behavior among four different hybrid poplars in a series of laboratory bioassays. Weevils did not discriminate between resistant and susceptible clones base(] on olfaction in pitfall bioassays or antennal responses but did discriminate against the most resistant hybrid, NM 6 (P. nigra L. X P. maximowiczii Henry), in choice and no-choice paired-twig feeding bioassays. In addition, the susceptible hybrid, TN 302-9 (P. trichocarpa Torrey and Gray X P. nigra), was preferred for feeding over Salix scouleriana Barratt ex Hooker, a preferred host in the wild. We conclude that resistance among hybrid poplars is in part based on antixenotic cues before oviposition.
86.Gries, R; Khaskin, G; Clearwater, J; Hasman, D; Schaefer, PW; Khaskin, E; Miroshnychenko, O; Hosking, G; Gries, G. (2005) (Z,Z)-6,9-Heneicosadien-11-one: Major sex pheromone component of painted apple moth, Teia anartoides.Journal of Chemical Ecology 31: 603-620 (Z,Z)-6,9-Heneicosadien-11-one: Major sex pheromone component of painted apple moth, Teia anartoides
Lymantriidae; Teia anartoides; painted apple moth; sex pheromone; (Z,Z)-6,9-heneicosadien-11-one; (Z,E)-6,8-heneicosadien-11-one; (6Z,9R,10S)-cis-9,10-epoxy-heneicosene; (E,E)-7,9-heneicosadien-6,11-dione; 6-hydroxy-(E,E)-7,9-heneicosadiene-11-one
(Z,Z)-6,9-Heneicosadien-11-one (Z6Z9-11-one-21Hy) was identified as the major sex pheromone component of the painted apple moth (PAM), Teia anartoides (Lepidoptera: Lymantriidae), on the basis of (1) comparative gas chromatographic-electroantennographic detection (GC-EAD) analyses, GC-mass spectrometry (MS), high-performance liquid chromatography (HPLC)-MS, and HPLC-UV/visible spectroscopy of pheromone gland extracts and authentic standards; (2) GC-EAD analyses of effluvia of calling females; and (3) wind tunnel and field trapping experiments with a synthetic standard. In field experiments in Australia, synthetic Z6Z9-11-one-21Hy as a single component attracted male moths. Wind tunnel experiments suggested that a 4-component blend consisting of Z6Z9-11-one-21Hy, (6Z,9R,10S)-cis-9, 10-epoxy-heneicosene (Z6-9R 10S-epo-21Hy), (E,E)-7,9-heneicosadien-6,11-dione (E7E9-6,11-dione-21Hy), and 6-hydroxy-(E,E)-7,9-heneicosadien-11-one (E7E9-6-ol-11-one-21Hy) (all present in pheromone gland extracts) might induce more males to orient toward, approach, and contact the source than did Z6Z9-11-one-21Hy as a single component. Additional experiments are needed to determine conclusively whether or not Z6-9R 10S-epo-21Hy, E7E9-6, 11-dione-21Hy, and E7E9-6-ol-11-one-21Hy might be minor sex pheromone components of PAM. Moreover, attractiveness of synthetic pheromone and virgin PAM females needs to be compared to determine whether synthetic pheromone could replace PAM females as trap baits in the pro-ram to monitor eradication of exotic PAM in New Zealand.
85.Gries, R; Khaskin, G; Gotoh, T; Schaefer, PW; Gries, G. (2005) (7Z,9E)-2-methyl-7,9-octadecadiene: A sex pheromone component of Lymantria bantaizana.Journal of Chemical Ecology 31: 879-891 (7Z,9E)-2-methyl-7,9-octadecadiene: A sex pheromone component of Lymantria bantaizana
Lymantria bantaizana; Lymantria dispar; Lymantria monacha; Lymantria fumida; Lymantria mathura; Lymantria xylina; (7Z,9E)-2-methyl7,9-octadecadiene; sex pheromone
Our objective was to identify the sex pheromone of Lymantria bantaizana (Lepidoptera: Lymantriidae) whose larvae feed exclusively on walnut, Juglans spp., in China, and Japan. Coupled gas chromatographic-electroantennographic detection (GC-EAD) analyses of pheromone gland extracts revealed a single EAD-active component. Retention index calculations of this compound on four GC columns suggested that it was a methyl-branched octadecadiene with conjugated double bonds. In GC-EAD analyses of 2-methyloctadecenes, (Z)-2-methyl-7-octadecene and (E)-2methyl-7-octadecene elicited the strongest antennal responses, suggesting that the double bond positions were at C7 and C9. In comparative GC-EAD analyses of pheromone gland extract and stereoselectively synthesized isomers (E, E; E,Z; Z,E; Z,Z) of 2-methyl-7,9-octadecadiene, the (E,Z)- and (Z,E)-isomer had retention times identical to that of the candidate pheromone, but only the latter isomer elicited strong EAD activity. Results of field experiments in Japan substantiated that (7Z,9E)-2-methyl-7,9-octadecadiene is the L. bantaizana sex pheromone, a compound previously unknown in the Lepidoptera. Detection surveys in North America for exotic Eurasian forest defoliators could include traps baited with the L. bantaizana pheromone.
84.Gries, R; Khaskin, G; Schaefer, P; Hahn, R; Gotoh, T; Gries, G. (2005) (7R,8S)-cis-7,8-epoxy-2-methyloctadec-17-ene: A novel trace component from the sex pheromone gland of gypsy moth, Lymantria dispar.Journal of Chemical Ecology 31: 49-62 (7R,8S)-cis-7,8-epoxy-2-methyloctadec-17-ene: A novel trace component from the sex pheromone gland of gypsy moth, Lymantria dispar
Asian gypsy moth; North American gypsy moth; Lymantria dispar; nun moth; Lymantria monacha; (7R,8S)-cis-7,8-epoxy-2-methyloctadec-17-ene; (7S,8R)-cis-7,8-epoxy-2-methyloctadec-17-ene; (7R,8S)-cis-7,8-epoxy-2-methyloctadecane; (7R,8S)-cis-7,8-epoxy-octadecane; 2-methyl-(Z)-7-octadecene; (+)-disparlure; (+)-monachalure
Considering the vast Eurasian distribution of gypsy moth, Lymantria dispar (Lepidoptera: Lymantriidae), the many subspecies, and their presence in different lymantriid communities, we tested the hypothesis that L. dispar populations in eastern Asia employ one or more pheromone components in addition to the previously known single component pheromone (7R, 8S)-cis-7,8-epoxy-2-methyloctadecane [= (+)-disparlure]. Coupled gas chromatographic electroantennographic detection (GC-EAD) analyses of pheromone gland extracts of female L. dispar sensu lato ( including both AGM and NAGM) on four GC columns (DB-5, DB-23, DB-210, and SP-1000) revealed a new trace component that eluted just before (DB- 5; DB- 210) or after (DB- 23, SP-1000) disparlure, and elicited strong antennal responses. Isolation of this compound by high-performance liquid chromatography and hydrogenation produced disparlure, suggesting that the new component had the molecular skeleton of disparlure, with one or more double bonds. Of all possible monounsaturated cis-7,8-epoxy2-methyloctadecenes, only cis-7,8-epoxy-2-methyloctadec-17-ene co-chromatographed with the insect-produced compound on all GC columns and elicited comparable antennal responses. In field experiments in Honshu (Japan) with enantioselectively synthesized compounds, (7R, 8S)-cis-7,8-epoxy-2-methyloctadec-17-ene (7R8S-epo-2me-17-ene-18Hy) was weakly attractive to male L. dispar, but was less effective as a trap bait than (+)-disparlure, and failed to enhance attractiveness of (+)-disparlure when tested in blends. The antipode, (7S, 8R)-cis-7,8-epoxy-2-methyloctadec-17-ene, was not attractive, and when added to (+)-disparlure and/or 7R8S-epo-2me-17-ene-18Hy reduced attractiveness. Thus, the biological role of 7R8S-epo-2me-17-ene-18Hy remains unclear. It may enhance pheromone attractiveness or specificity in other L. dispar populations within their vast Eurasian distribution.
82.Gries, R., Khaskin, G., Bennett, R.G., Miroshnychenko, A., Burden, K. and Gries, G. (2005) (S,S)-2,12-, (S,S)-2,13-, and (S,S)-2,14-Diacetoxyheptadecanes: Sex Pheromone Components of Red Cedar Cone Midge, Mayetiola thujae.Journal of Chemical Ecology 31: 2933-2946 (S,S)-2,12-, (S,S)-2,13-, and (S,S)-2,14-Diacetoxyheptadecanes: Sex Pheromone Components of Red Cedar Cone Midge, Mayetiola thujae.
We identified, synthesized, and field-tested the sex pheromone of female red cedar cone midge Mayetiola thujae (Hedlin) (Diptera: Cecidomyiidae), a pest insect in red cedar Thuja plicata seed orchards. Coupled gas chromatographic (GC)-electroantennographic detection analyses of pheromone extract revealed three components (A, B, C) that elicited responses from antennae of males, all of which occurred below the detection threshold of the mass spectrometer and thus had to be identified without spectroscopic data. Taking into account (1) their retention indices (RI) on three GC columns (DB-5, DB-23, and DB-210), (2) intercolumn RI differentials, and (3) the molecular structures of known cecidomyiid pheromones, we synthesized seven candidate pheromone components: 2,10-, 2,11-, 2,12-, 2,13-, 2,14-, 2,15- and 2,16-diacetoxyheptadecanes. Of these, 2,12-, 2,13-, and 2,14-diacetoxyheptadecane had RIs on all columns consistent with those of A, B, and C and elicited strong antennal responses when tested at picogram levels. In field experiments with the twelve stereoselectively synthesized stereoisomers, only the SS-stereoisomers of 2,12-, 2,13-, and 2,14-diacetoxyheptadecane attracted male M. thujae. The three-component SS-stereoisomer blend was more attractive than the 12-component blend of all stereoisomers, suggesting that one or several nonnatural stereoisomers are inhibitory. One-, two-, and three-component lures of the SS-stereoisomers were equally effective in attracting male M. thujae, indicating redundancy in the pheromone. Identification of the M. thujae sex pheromone will allow development of pheromone-based monitoring, and possibly control, of M. thujae populations in T. plicata seed orchards.
81. Jumean, Z; Gries, R; Unruh, T; Rowland, E; Gries, G. (2005) Identification of the larval aggregation pheromone of codling moth, Cydia pomonella.Journal of Chemical Ecology 31: 911-924 Identification of the larval aggregation pheromone of codling moth, Cydia pomonella
Codling moth; larvae; Cydia pomonella; Mastrus ridibundus; aggregation pheromone; heptanal; octanal; nonanal; decanal; (E)-2-octenal; (E)-2-nonenal; sulcatone; geranylacetone; (+)-limonene; myrcene; 3-carene
Mature larvae of the codling moth, Cydia pomonella L. (Lepidoptera: Olethreutidae), exit the fruit and seek sites suitable for pupation. Spinning cocoons in such sites, larvae produce a complex, cocoon-derived blend of volatiles recently shown to attract and/or arrest both conspecific larvae and the prepupal parasitoid Mastrus ridibundus Gravenhorst (Hymenoptera: Ichneumonidae). Here we report components of this blend that constitute the pheromone of fifth-instar C pomonella larvae. Thirty-one two-choice olfactometer experiments showed that a blend of synthetic (E)-2octenal, (E)-2-nonenal, sulcatone, and geranylacetone, in combination with either 3-carene and/or three saturated aldehydes (octanal, nonanal, decanal), elicited behavioral responses from C. pomonella larvae. In on-tree experiments with corrugated cardboard bands as pupation sites for larvae affixed to tree trunks, and with laboratory-reared larvae released onto such trees, more larvae cocooned in those halves of cardboard bands baited with cocoonspinning conspecific larvae, or with synthetic pheromone components, than in unbaited control halves of the bands. With the larval aggregation pheromone identified in this study, there might be an opportunity to manipulate C. pomonella larvae in commercial fruit or nut orchards.
80. Jumean, Z; Unruh, T; Gries, R; Gries, G. (2005) Mastrus ridibundus parasitoids eavesdrop on cocoon-spinning codling moth, Cydia pomonella, larvae.Naturwissenschaften 92: 20-25 Mastrus ridibundus parasitoids eavesdrop on cocoon-spinning codling moth, Cydia pomonella, larvae
Cocoon-spinning larvae of the codling moth, Cydia pomonella L. (Lepidoptera: Olethreutidae) employ a pheromone that attracts or arrests conspecifics seeking pupation sites. Such intraspecific communication signals are important cues for illicit receivers such as parasitoids to exploit. We tested the hypothesis that the prepupal C. pomonella parasitoid Mastrus ridibundus Gravenhorst (Hymenoptera: Ichneumonidae) exploits the larval aggregation pheromone to locate host prepupae. In laboratory olfactometer experiments, female M. ridibundus were attracted to 3-day-old cocoons containing C. pomonella larvae or prepupae. Older cocoons containing C. pomonella pupae, or larvae and prepupae excised from cocoons, were not attractive. In gas chromatographic-electroantennographic detection (GC-EAD) analyses of bioactive Porapak Q extract of cocoon-derived airborne semiochemicals, ten compounds elicited responses from female M. ridibundus antennae. Comparative GC-mass spectrometry of authentic standards and cocoon-volatiles determined that these compounds were 3-carene, myrcene, heptanal, octanal, nonanal, decanal, (E)-2-octenal, (E)-2-nonenal, sulcatone, and geranylacetone. A synthetic 11-component blend consisting of these ten EAD-active compounds plus EAD-inactive (+)-limonene (the most abundant cocoon-derived volatile) was as effective as Porapak Q cocoon extract in attracting both female M. ridibundus and C. pomonella larvae seeking pupation sites. Only three components could be deleted from the 11-component blend without diminishing its attractiveness to M. ridibundus, which underlines the complexity of information received and processed during foraging for hosts. Mastrus ridibundus obviously "eavesdrop" on the pheromonal communication signals of C. pomonella larvae that reliably indicate host presence.
79. McLeod, G; Gries, R; von Reuss, SH; Rahe, JE; McIntosh, R; Konig, WA; Gries, G. (2005) The pathogen causing Dutch elm disease makes host trees attract insect vectors.Proc Roy Soc B-Biol Sci 272: 2499-2503 The pathogen causing Dutch elm disease makes host trees attract insect vectors
Dutch elm disease; Ulmus americana; fungal pathogen; Ophiostoma novo-ulmi; Hylurgopinus rufipes; semiochemicals
Dutch elm disease is caused by the fungal pathogen Ophiostoma novo-ulmi which is transmitted by the native elm bark beetle, Hylurgopinus rufipes. We have found that four semiochemicals (the monoterpene (-)- beta-pinene and the sesquiterpenes (-)-alpha-cubebene, (+)-spiroaxa-5,7-diene and (+)-delta-cadinene) from diseased American elms, Ulmus americana, synergistically attract H. rufipes, and that sesquiterpene emission is upregulated in elm trees inoculated with O. novo-ulmi. The fungus thus manipulates host trees to enhance their apparency to foraging beetles, a strategy that increases the probability of transportation the pathogen to new hosts.
78. Schlamp, K.K., Gries R., Khaskin, G, Brown, K., Khaskin E., Judd, G.J.R., and Gries, G. (2005) Pheromone Components from Body Scales of Female Anarsia lineatella Induce Contacts by Conspecific Males.Journal of Chemical Ecology 31: 2897-2911 Pheromone Components from Body Scales of Female Anarsia lineatella Induce Contacts by Conspecific Males.
Pheromonal communication of adult peach twig borers, Anarsia lineatella Zeller (Lepidoptera: Gelechiidae), was reinvestigated based on recent findings that virgin female-baited traps were more attractive to mate-seeking males than a two-component synthetic sex pheromone consisting of (E)-5-decen-1-yl acetate (1000 mu g) and (E)-5-decen-1-ol (100 mu g), suggesting that females use additional pheromone components. Hypothesizing that these additional components may be released from body parts other than abdominal sex pheromone glands, we extracted female body scales and analyzed aliquots by coupled gas chromatographic-electroantennographic detection (GC-EAD) and GC-mass spectrometry. Eight straight-chain and four methylated aliphatic hydrocarbons, as well as two acetates, all elicited responses from excised male antennae. In laboratory experiments with synthetic candidate pheromone components, a combination of octadecyl acetate, (R)-11-methyltricosane, and (S)-11-methyltricosane in the presence of gland-derived sex pheromone components were shown to elicit contact of female decoys by males. However, body pheromone components did not enhance attractiveness of sex pheromone components in field trapping experiments, suggesting that they are effective only at close range and that other stimuli are responsible for superior attractiveness of female-baited traps.
77. Choi, MY; Khaskin, G; Gries, R; Gries, G; Roitberg, BD; Raworth, DA; Kim, DH; Bennett, RG. (2004) (2R,7S)-diacetoxytridecane: Sex pheromone of the aphidophagous gall midge, Aphidoletes aphidimyza.Journal of Chemical Ecology 30: 659-670 (2R,7S)-diacetoxytridecane: Sex pheromone of the aphidophagous gall midge, Aphidoletes aphidimyza
Aphidoletes aphidimyza; Cecidomyiidae; sex pheromone; stereoisomers; (2R,7S)-diacetoxytridecane; (2S,7R)-diacetoxytridecane; (2R,7R)-diacetoxytridecane; (2S,7S)-diacetoxytridecane
In a recent study, evidence was presented that females of the aphidophagous midge Aphidoletes aphidimyza (Rondi) (Diptera: Cecidomyiidae) release a sex pheromone to attract mates. Our objectives were to identify and bioassay the pheromone. Coupled gas chromatographic-electroantennographic detection (GC-EAD) analyses of untreated and hydrogenated pheromone extract on three fused-silica columns (DB-5, DB-23, DB-210) revealed a single compound that elicited responses from male antennae. Retention index calculations of this candidate pheromone (CP) suggested that it was a di-acetate. Considering that most of the presently identified cecidomyiid pheromones consist of a 13-carbon chain with (at least) one acetate group in C2, we synthesized 2,6-, 2,7-, 2,8-, 2,9-, 2,10-, 2,11-, and 2,12-diacetoxytridecane. In GC analyses of these compounds, only 2,7- diacetoxytridecane cochomatographed with CP on all columns. In laboratory two-choice experiments with stereospecifically synthesized stereoisomers, only (2R, 7S)-diacetoxytridecane elicited significant anemotatic responses by male A: aphidimyza. In trapping experiments in greenhouse compartments, only traps baited with (2R, 7S)-diacetoxytridecane captured significant numbers of male A. aphidimyza, clearly revealing the absolute configuration of the pheromone. Failure of the stereoisomeric mixture (containing all four stereoisomers including the pheromone) to attract males is due to inhibitory characteristics of the (2R, 7R)- and (2S, 7R)-stereoisomers. The pheromone of zoophagous A. aphidimyza resembles those from phytophagous cecidomyiid midges, suggesting a common, diet-independent pathway for pheromone biosyntheses.
76.Gries, R; Reckziegel, A; Bogenschutz, H; Kontzog, HG; Schlegel, C; Francke, W; Millar, JG; Gries, G. (2004) (Z,Z)-11,13-hexadecadienyl acetate and (Z,E)-11,13,15-hexadecatrienyl acetate: synergistic sex pheromone components of oak processionary moth, Thaumetopoea processionea (Lepidoptera : Thaumetopoeidae).Chemoecology 14: 95-100 (Z,Z)-11,13-hexadecadienyl acetate and (Z,E)-11,13,15-hexadecatrienyl acetate: synergistic sex pheromone components of oak processionary moth, Thaumetopoea processionea (Lepidoptera : Thaumetopoeidae)
Thaumetopoea processionea; Lepidoptera; Thaumetopoeidae; sex pheromone; (Z,Z)-11,13-hexadecadienyl acetate; (Z,E)-11,13,15-hexadecatrienyl acetate; (E,Z)-11,13,15-hexadecatrienyl acetate; (E,E)-11,13,15-hexadecatrienyl acetate
Our objective was to identify sex pheromone components of the oak processionary moth, Thaumetopoea processionea (Lepidoptera: Thaumetopoeidae), whose larvae defoliate oak, Quercus spp., forests in Eurasia and impact human health. Coupled gas chromatographic-electroantennographic detection (GC-EAD) and GC-mass spectrometric (MS) analyses of pheromone gland extract of female T. processionea revealed two consistently EAD-active compounds. They were identified as (Z,Z)-11,13-hexadecadienyl acetate (Z11,Z13-16:OAc) and (Z,E)-11,13,15-hexadecatrienyl acetate (Z11,E13,15-16:OAc) by comparative GC, GC-MS and GC-EAD analyses of insect-produced compounds and authentic standards. In replicated field experiments (2000, 2001) in Nordbaden, Sudbaden and Sachsen-Anhalt (Germany), Z11,Z13-16:OAc and Z11,E13,15-16:OAc in combination, but not singly, attracted significant numbers of male moths. It will now be intriguing to investigate whether Z11,E13,15-16:OAc, or its corresponding alcohol or aldehyde, serves as a pheromone component also in other species of the Thaumetopoeidae.
74. Duthie, B; Gries, G; Gries, R; Krupke, C; Derksen, S. (2003) Does pheromone-based aggregation of codling moth larvae help procure future mates?Journal of Chemical Ecology 29: 425-436 Does pheromone-based aggregation of codling moth larvae help procure future mates?
Cydia pomonella; larvae; pupae; aggregation behavior; aggregation pheromone; sex pheromone; mate attraction; delayed mating; mating strategy; protandry; fitness
In field and laboratory bioassay experiments, we show that larvae of the codling moth, Cydia pomonella, cocoon in aggregations. This aggregation behavior of fifth-instar larvae prior to pupation and arrestment of eclosed adult males by mature female pupae seems to allow mating as soon as an adult female ecloses. This synchronous timing is realized because foraging fifth-instar are attracted by cocoon-spinning larvae and prepupae, but not by pupae, and because male pupae develop faster than female pupae. Eclosed males are arrested by sex pheromone that disseminates from female pupae even before adult females eclose. Communication in C. pomonella within and among developmental stages (larva-larva and pupa-adult, respectively) may be a strategy to procure mates. If so, our data add to current knowledge that attraction of mates in insects relies on communication among adults, or pupae and adults.
73.Gries, R; Khaskin, G; Khaskin, E; Foltz, JL; Schaefer, PW; Gries, G. (2003) Enantiomers of (Z,Z)-6,9-heneicosadien-11-ol: Sex pheromone components of Orgyia detrita.Journal of Chemical Ecology 29: 2201-2212 Enantiomers of (Z,Z)-6,9-heneicosadien-11-ol: Sex pheromone components of Orgyia detrita
ditrysian Lepidoptera; Lymantriidae; Orgyia detrita; sex pheromone; (6Z,9Z,11S)-6,9-heneicosadien-11-ol; (6Z,9Z,11R)-6,9-heneicosadien-11-ol; (6Z,9Z)-6,9-eicosadien-11-ol; (6Z,9Z)-6,9-docosadien-11-ol
(6Z, 9Z, 11S)- 6,9-Heneicosadien-11-ol (Z6Z9-11S-ol-C21) and (6Z; 9Z; 11R)-6,9-heneicosadien-11-ol (Z6Z9-11R-ol-C21) were identified as major sex pheromone components of female tussock moths, Orgyia detrita Guerin-Meneville (Lepidoptera: Lymantriidae), on the basis of (1) analyses of pheromone gland extracts of female O. detrita by coupled gas chromatographic-electroantennographic detection (GC-EAD) and GC mass spectrometry, and (2) field trapping experiments with synthetic standards. Z6Z9-11S-ol-C21 and Z6Z9-11R-ol-C21 in combination, but not singly, attracted significant numbers of male moths. Racemic Z6Z9-11-ol-C21 was more attractive than the 1: 3.5 ( R: S) blend ratio found in pheromone gland extracts from female moths. Lower and higher homologues of Z6Z9-11-ol-C21 were also detected in GC-EAD recordings of pheromone extracts, and the racemic compounds enhanced attractiveness of Z6Z9-11-ol-C21 in field experiments. Because of trace amounts of these homologues in extracts, their enantiomeric composition could not be determined. This is the first report of secondary alcohols as pheromone components in the ditrysian ( advanced) Lepidoptera.
72. Sasaerila, Y; Gries, R; Gries, G; Khaskin, G; King, S; Takacs, S; Hardi. (2003) Sex pheromone components of male Tirathaba mundella (Lepidoptera : Pyralidae).Chemoecology 13: 89-93 Sex pheromone components of male Tirathaba mundella (Lepidoptera : Pyralidae)
Tirathaba mundella; Lepidoptera; Pyralidae; male pheromone; (3S,6S)-2,2,6-trimethyl-6-vinyl-tetrahydropyran-3-ol; 4-hydroxy-3-methoxy-benzaldehyde; 6,10,14-trimethyl-2-pentadecanol; 6,10,14-trimethyl-2-pentadecanone; vanillin; gas chromatographic-electroantennographic; detection; field cage bioassay experiments
During peak calling activity by male oil palm bunch moths, Tirathaba mundella Walker (Lepidoptera: Pyralidae), their hairpencils, wings or entire body were extracted in hexane. Gas chromatographic-electroantennographic detection (GC-EAD) analyses of hair pencil extracts revealed four compounds that consistently elicited responses from female antennae. The NMR spectrum of isolated compound 1, and mass spectra and retention indices of compounds 1-4 suggested that they were (3S,6S)-2,2,6-trimethyl-6-vinyl-tetrahydro-pyran-3-ol (1), 4-hydroxy-3-methoxy-benzaldehyde (2, vanillin), 6,10,14-trimethyl-2-pentadecanone (3), and 6,10,14-trimethyl-2-pentadecanol (4). Comparative GC and GC-MS analyses of hair pencils extract and synthetic standards confirmed these structural assignments. Moreover, comparative chromatography of synthetic and hairpencil-isolated 1 on a Cyclodex-B column (which separated the four stereoisomers with baseline resolution) revealed that male T. mundella produce the SS-stereoisomer (SS-1). In field cage bioassay experiments in Palembang, Indonesia, synthetic SS-1 and vanillin in combination, but not singly, attracted female T. mundella. SS-1 plus vanillin were as effective as male T. mundella in attracting females. Compounds 3 and 4 did not enhance the blend's attractiveness.
71. Takacs, S; Mistal, C; Gries, G. (2003) Communication ecology of webbing clothes moth: attractiveness and characterization of male-produced sonic aggregation signals.Journal of Applied Entomology-Zeitschrift Fur Angewandte Entomologie 127: 127-133 Communication ecology of webbing clothes moth: attractiveness and characterization of male-produced sonic aggregation signals
We tested the hypothesis that the webbing clothes moth, Tineola bisselliella (Hum.) (Lep., Tineidae), uses sonic signals in addition to pheromonal signals for communication. To record sound from individual or groups of moths of either or both sexes, we used a digital recording system, microphones sensitive to sonic and/or ultrasonic frequencies, and speakers capable of emitting sonic and ultrasonic sound. In a soundproof environment, male T. bisselliella produced sounds of 27 decibels (dB, sound pressure level; 0 dB corresponds to 20 mu Pa), with a base frequency of 40-50 Hz and a harmonic frequency of 80-100 Hz. Sound intensity and frequency increased to 55 dB and 65-75 Hz (with greater than or equal to3 harmonic frequencies), respectively, when calling males were near (<2 cm) conspecifics of either sex. There was no evidence that females produce sound and no evidence for ultrasonic sound production by either sex. In Y-tube bioassay experiments, virgin male and female T. bisselliella preferred played-back sonic signals from males to silent control stimuli, whereas mated females showed no preference for either stimulus. In arena bioassay experiments, males as well as virgin and mated females preferred played-back sonic signals from males over a white noise control. Use of pheromonal and sonic signals by T. bisselliella would be adaptive, because the capacity for sonic communication persists even if sensory adaptation or habituation to pheromonal signals occurred. This hypothesis is consistent with the fact that other inhabitants of enclosed microhabitats, such as the greater wax moth, Galleria mellonella L., and Indian meal moth, Plodia interpunctella (Hb.), have also evolved analogous multimodal communication systems.
70. Tremblay, MN; Gries, G. (2003) Pheromone-based aggregation behaviour of the firebrat, Thermobia domestica (Packard) (Thysanura : Lepismatidae).Chemoecology 13: 21-26 Pheromone-based aggregation behaviour of the firebrat, Thermobia domestica (Packard) (Thysanura : Lepismatidae)
Thermobia domestica; Ctenolepisma longicaudata; Lepisma saccharina; Thysanura; Lepismatidae; pheromone; aggregation; arrestment; scales; frass
We tested the hypothesis that aggregation behaviour of the firebrat, Thermobia domestica (Packard) (Thysanura: Lepismatidae), an inhabitant of enclosed microhabitats, is mediated, at least in part, by a pheromone. Individual insects were released into the central chamber of a 3-chambered olfactometer and test stimuli were placed in lateral chambers. Paper discs previously exposed for 3 days to 10 female, male, or juvenile T domestica were all preferred by female, male, or juvenile T domestica over unexposed paper discs, indicating the presence of an aggregation/arrestment pheromone. In additional experiments, frass and scales from female T domestica, tested singly and in combination, proved not to be the source of the pheromone. Physical contact was required for pheromone recognition, indicating that the pheromone arrests rather than attracts conspecifics. Arrestment by the long-tailed silverfish, Ctenolepisma longicaudata Escherich (Thysanura: Lepismatidae), but not by the common silverfish, Lepisma saccharina L. (Thysanura: Lepismatidae), to T domestica exposed paper discs suggests closer phylogenetic relatedness between C. longicaudata and T domestica, than between C longicaudata and L saccharina. Whether C. longicaudata or L. saccharina produce an aggregation signal, and whether T domestica respond to this signal is unknown.
69. Bedard, C; Gries, R; Gries, G; Bennett, R. (2002) Cydia strobilelia (Lepidoptera : Tortricidae): antennal and behavioral responses to host and nonhost volatiles.Canadian Entomologist 134: 793-804 Cydia strobilelia (Lepidoptera : Tortricidae): antennal and behavioral responses to host and nonhost volatiles
Female spruce seed moths, Cydia strobilella (L.) (Lepidoptera: Tortricidae), oviposit on seed cones of most North American spruces (Picea spp.) (Pinaceae) at the time of pollination, and larvae feed on seeds in the maturing cones. We tested the hypothesis that host-seeking moths respond to volatiles from both host and nonhost trees. In coupled gas chromatographic - electroantennographic detection (GC-EAD) analyses of extracts of spruce seed cone volatiles, >17 compounds elicited antennal responses from male and female C. strobilella. A blend of seven compounds, including (-)-alpha-pinene and (-)-beta-pinene, (alpha-longipinene and a-humulene, Z3-hexenol, methyl eugenol, and cymen-8-ol, was more attractive to female C. strobilella in laboratory bioassay experiments than the complete seed cone volatile blend, containing these compounds at equivalent quantities and ratios. In GC-EAD analyses of volatile extracts' from nonhost angiosperm trees, EAD-activity was associated with compounds present in (almost) every volatile source, including trembling aspen, Populus tremuloides (Michx.) (Salicaceae), paper birch, Betula papyrifera (Marsh.) (Betulaceae), black cottonwood, Populus balsamifera trichocarpa (Torr. and Gray) (Salicaceae), and bigleaf maple, Acer macrophyllum (Pursh.) (Aceraceae). In a field experiment in the interior of British Columbia, the antennally active nonhost aldehydes, alcohols, and (+/-)-conophthorin all reduced captures of male C. strobilella in pheromone-baited traps. Collectively, our data suggest that host selection by C. strobilella is mediated, in part, by semiochemicals from both host and nonhost trees.
67.Gries, G; Schaefer, PW; Gries, R; Fan, YB; Higashiura, Y; Tanaka, B. (2002) 2-Methyl-(Z)-7-octadecene: Sex pheromone of allopatric Lymantria lucescens and L-serva.Journal of Chemical Ecology 28: 469-478 2-Methyl-(Z)-7-octadecene: Sex pheromone of allopatric Lymantria lucescens and L-serva
Lymantriidae; Lymantria lucescens; Lymantria serva; sex pheromone; reproductive isolation; 2-methyl-(Z)-7-octadecene; (+)-disparlure; (-)-disparlure; (+)-monachalure; (-)-monachalure; (7R,8S)-cis-7,8-epoxy-2methyloctadecane; (7S,8R)-cis-7,8-epoxy-2-methyloctadecane; (7R,8S)-cis7,8-epoxy-octadecane; (7S,8R)-cis-7,8-epoxy-octadecane
Our objective was to identify the sex pheromone of Lymantria lucescens and Lymantria serva (Lepidoptera: Lymantriidae), whose larvae defoliate, respectively, Quercus spp. in temperate regions and Ficus spp. in the subtropics. Coupled gas chromatographic-electroantennographic (GC-EAD) detection analyses of pheromone gland extracts revealed one EAD active compound produced by female L. lucescens and by female L. serva. This was identified as 2-methyl-(Z)-7-octadecene (2me-Z7-18Hy) by retention index calculations on DB-5, DB-23, and DB-210 columns and by comparative GC-mass spectrometric (MS) and GC-EAD analyses of the insect-produced candidate pheromone and synthetic 2me-Z7-18Hy. In field experiments, traps baited with 2me-Z7-18Hy captured male L. lucescens near Toyota City, Japan, and male L. serva in Taipei, Taiwan, Allopatric distribution of L. lucescens and L. serva seems to allow both species to use the same sex pheromone without compromising its specificity.
66.Gries, R; Khaskin, G; Gries, G; Bennett, RG; King, GGS; Morewood, P; Slessor, KN; Morewood, WD. (2002) (Z,Z)-4,7-tridecadien-(S)-2-yl acetate: Sex pheromone of Douglas-fir cone gall midge, Contarinia oregonensis.J. Chem. Ecol. 28: 2283-2297 (Z,Z)-4,7-tridecadien-(S)-2-yl acetate: Sex pheromone of Douglas-fir cone gall midge, Contarinia oregonensis
Douglas-fir cone gall midge; Contarinia oregonensis; Cecidomyiidae; sex pheromone; enantiomers; (Z,Z)-4,7-tridecadien-(S)-2-yl acetate; (4Z)-4,7-tridecadien-(R)-2-yl acetate
Our objectives were to identify and field test the sex pheromone of female Douglas-fir cone gall midge, Contarinia oregonensis (Diptera: Cecidomyiidae). Coupled gas chromatographic-electroantennographic detection (GC-EAD) analyses of pheromone extract revealed a single compound (A) that elicited responses from male antennae. Hydrogenation of pheromone extract, followed by renewed GC-EAD analysis, revealed a new EAD-active compound with chromatographic characteristics identical to those of tridecan-2-yl acetate on five fused silica columns (DB-5, DB-210, DB-23, SP-1000, and Cyclodex-B). Syntheses, chromatography, and retention index calculations of all possible tridecen-2-yl acetates suggested that the candidate pheromone A was a tridecadien-2-yl acetate with nonconjugated double bonds. Synthetic candidate pheromone component (Z,Z)-4,7-tridecadien-2-yl acetate (Z4Z7) cochromatographed with A on all analytical columns and elicited comparable antennal activity. In GC-EAD analyses that separated the enantiomers (Z,Z)4,7-tridecadien-(S)-2-yl acetate (2S-Z4Z7) and (Z,Z)-4,7-tridecadien-(R)-2-yl acetate (2R-Z4Z7) with baseline resolution, only 2S-Z4Z7 as a component in a racemic standard or in pheromone extract elicited antennal responses. In Douglas-fir seed orchards, sticky traps baited with 2S-Z4Z7 captured male C. oregonensis, whereas 2R-Z4Z7 was behaviorally benign. Comparable catches of males in traps baited with racemic Z4Z7 (50 mug) or virgin female C. oregonensis suggested that synthetic pheromone baits could be developed for monitoring C. oregonensis populations in commercial Douglas-fir seed orchards. DOI PubMed
65. Morewood, P; Morewood, WD; Bennett, RG; Gries, G. (2002) Potential for pheromone-baited traps to predict seed loss caused by Contarinia oregonensis (Diptera : Cecidomyiidae).Canadian Entomologist 134: 689-697 Potential for pheromone-baited traps to predict seed loss caused by Contarinia oregonensis (Diptera : Cecidomyiidae)
In seed orchards of Douglas-fir, Pseudotsuga menziesii (Mirbel) Franco (Pinaceac), located in Washington State and Oregon, United States, we tested whether catches of male Douglas-fir cone gall midges, Contarinia oregonensis Foote, in pheromone-baited traps can be used to predict the extent of galled scales (=seed loss at harvest) caused by developing larvae. In 2000, 27 experimental blocks (4-7 ha each) were selected. In each block we recorded mean numbers of (i) male C. oregonensis captured in 20 pheromone-baited Wing traps, (ii) egg-infested scales in up to 50 conelets in early spring, and (iii) galled scales in up to 50 cones in late summer. In 2001, the experiment was repeated with 20 Delta traps in each of 26 experimental blocks. Moreover, catches of C. oregonensis and nontarget insects in Delta traps and Wing traps were compared in one additional orchard block in 2001. In both years there were positive correlations between mean numbers of egg-infested and galled scales and between mean numbers of captured male C. oregonensis and mean numbers of both egg-infested and galled scales, particularly when only experimental blocks with greater than or equal to50% of trees bearing at least 5 conelets were considered. Our results suggest that 4 or 2 captured male C. oregonensis in Wing or Delta traps, respectively, warrant insecticidal control of C oregonensis. Delta traps, which captured fewer nontarget insects, would be more suitable than Wing traps for operational implementation of this technology.
64. Rhainds, M; Gries, G; Ho, CT; Chew, PS. (2002) Dispersal by bagworm larvae, Metisa plana: effects of population density, larval sex, and host plant attributes.Ecological Entomology 27: 204-212 Dispersal by bagworm larvae, Metisa plana: effects of population density, larval sex, and host plant attributes
bagworm; ballooning; density- and defoliation-dependent processes; dispersal; flightless females; Metisa plana; sex-specific larval adaptation
1. The work reported here investigated the incidence of dispersal by bagworm larvae Metisa plana (Walker) (Lepidoptera: Psychidae), a species with apterous females and winged males. 2. A mark-recapture study conducted in a plantation of oil palm revealed that a significant proportion of larvae undertakes multiple episodes of ballooning, and suggested that ballooning represents a strategy for foraging both within and between hosts. 3. Experiments conducted in a controlled cage environment indicated that increasing population density and defoliation of oil palm both promote dispersal by larvae. 4. Neonatal larvae typically remained on the host where they emerged, indicating that pupation site of late-instar females influences the distribution of their progeny, and suggesting a high level of genetic relatedness in localised bagworm populations. 5. Density-dependent dispersal may generate relatively uniform distributions of M. plana in plantations of oil palm, by simultaneously stabilising populations on heavily infested palms and redistributing larvae on lightly infested palms. 6. The rate of ballooning was greater for female than for male larvae, possibly resulting from the sex-specific impact of population density on reproductive success or from late-instar females seeking suitable oviposition sites for their future progeny.
63. Rhainds, M; Lan, CC; Zhen, ML; Gries, G. (2002) Incidence, symptoms, and intensity of damage by three coffee stem borers (Coleoptera : Cerambycidae) in South Yunan, China.Journal of Economic Entomology 95: 106-112 Incidence, symptoms, and intensity of damage by three coffee stem borers (Coleoptera : Cerambycidae) in South Yunan, China
Xylotrechus quadripes; Acalolepta cervina; Bacchisa pallidiventris; Coffea arabica
Sampling studies were conducted in coffee plantations in South Yunan to assess the incidence, symptoms, and intensity of damage by three stem borers: Xylotrechus quadripes (Chevrolat), Acalolepta cervina (Hope), and Bacchisa sp. near pallidiventris (Thomson). Of 5,690 plants sampled in eight plantations, 440 were infested with A. cervina, 63 with X. quadripes, and three with B. pallidiventris. Plants 5-7 yr old were 10 times more heavily infested with X. quadripes than 3- to 4-yr-old plants, whereas both age groups of plants had similar levels of infestation with A. cervina. Larval galleries of the three borer species markedly differ: A. cervina and B. pallidiventris larvae develop in subcortical. galleries in the main stem (A. cervina) and lateral branches (B. pallidiventris), whereas larval galleries of X. quadripes intermittently punctuate and transverse the xylem of main stems or lateral branches. Significantly more plant tissue was damaged in stems infested with X. quadripes than in those infested with A. cervina or B. pallidiventris. Stems infested with A. cervina or B. pallidiventris generally had only one or a few pupation chambers, whereas stems infested with X. quadripes contained numerous chambers. Quantitative and qualitative data collected through this study provide farmers with diagnostic tools to determine which borer species infested coffee plants. Comparison of life history traits and intensity of damage for the three borer species indicates that X. quadripes is the most severe pest of coffee in Yunan, and suggests that populations of X. quadripes have the greatest potential to steadily increase with time.
61. Takacs, S; Gries, G; Gries, R. (2002) Where to find a mate? Resource-based sexual communication of webbing clothes moth.Naturwissenschaften 89: 57-59 Where to find a mate? Resource-based sexual communication of webbing clothes moth
Mate location in moths typically entails long-range attraction of males to female-produced pheromone. Here, we show that male and female webbing clothes moths, Tineola bisselliella, seek larval habitats (dry carrion, animal lairs, etc) to encounter mates. With males seeking, and arriving at, larval habitat earlier at night than females, male-produced pheromonal and sonic signals enhance the habitat's attractiveness to females. This resource-based mating strategy of T. bisselliella differs from that known for most other moths. It may h evolved in response to larval habitats that are patchy and temporary, but that disseminate attractive semiochemicals so abundantly that T. bisselliella encounter them more readily than their own pheromones.
60. Cabrera, A; Eiras, AE; Gries, G; Gries, R; Urdaneta, N; Miras, B; Badji, C; Jaffe, K. (2001) Sex pheromone of tomato fruit borer, Neoleucinodes elegantalis.Journal of Chemical Ecology 27: 2097-2107 Sex pheromone of tomato fruit borer, Neoleucinodes elegantalis
Neoleucinodes elegantalis; Lepidoptera; Crambidae; sex pheromone; (E)-11-hexadecenol; (Z)-3,(Z)-6,(Z)-9-tricosatriene; (Z)-11-hexadecenol; GC-EAD; tomato
Five candidate pheromone components were identified by analyzing pheromone gland extracts by gas chromatography (GC, coupled GC-electro-antennographic detection (EAD), and coupled GC-mass spectrometry (MS): (E)-1 1-hexadecenol(E1 1-16: OH), (Z)-11-hexadecenol (ZI 1- 16: OH), (E)-11-hexadecenal, (E)-11-hexadecenyl acetate, and, (Z)-3,(Z)-6,(Z)-9-tricosatriene (Z3,Z6,Z9-23: Hy). In electroantennogram (EAG) recordings, synthetic El I 16: OH elicited stronger antennal responses at low doses than other candidate pheromone components. Field tests demonstrated that synthetic El 1-16: OH as a trap bait was effective in attracting males, whereas addition of ZI 1-16: OH inhibited the males' response. Z3,Z6,Z9-23: Hy strongly enhanced attractiveness of El 1-16: OH, but was not attractive by itself. A pheromone blend with synergistic behavioral activity of an alcohol (El 1- 16: OH) and hydrocarbon (Z3,Z6,Z9-23 : Hy) component is most unusual in the Lepidoptera. The synthetic two-component pheromone is approximately 60 times more attractive than the female-produced blend and might facilitate the control of this pest.
59. Duff, CM; Gries, G; Mori, K; Shirai, Y; Seki, M; Takikawa, H; Sheng, T; Slessor, KN; Gries, R; Maier, CT; Ferguson, DC. (2001) Does pheromone biology of Lambdina athasaria and L-pellucidaria contribute to their reproductive isolation?J. Chem. Ecol. 27: 431-442 Does pheromone biology of Lambdina athasaria and L-pellucidaria contribute to their reproductive isolation?
Geomenidae; 7-methylheptadecane; 7,11-dimethylhepadecane; pheromone chirality; diel periodicity of pheromonal communication; seasonality of flight; reproductive isolating mechanisms; synonomy
Recently, 7-methylheptadecane and 7,11-dimethylheptadecane have been reported as sex pheromone components of both spring hemlock looper (SHL), Lambdina athasaria, and pitch pine looper (PPL), Lambdina pellucidaria. Our objective was to test the hypothesis that SHL and PPL are reproductively isolated, in part, through species specificity in: (1) absolute configuration of pheromone components, (2) diel periodicity of pheromonal communication, and/or (3) seasonal flight period. In coupled pas chromatographic-electroantennographic detection (GC-EAD) analyses of stereoselectively synthesized (7S)- and (7R)-7-methylheptadecane [7S; 7R] as well as (7S,11S)-, (7R,11R)-, and (meso-7,11)-7,11-dimethylheptadecane [7S,11S; 7R,11R, meso-7,11], only 7S and mese-7,11 elicited responses by male SHL and PPL antennae. In field experiments, male SHL and PPL were attracted only to lures containing 7S plus meso-7,11. In hourly recordings of trap-captured males, SHL and PPL in their respective habitats were trapped between 24:00 and 03:00 hr. Capture of both SHL and PPL in pheromone-baited traps throughout June indicated overlapping seasonal Eight periods. These findings of identical absolute configuration of pheromoal components, diel periodicity of pheromonal communication, and overlap of seasonal flight periods support synonymy of SHL and PPL. Finite taxonomic classification of PPL and SHL must await careful assessment of further criteria. such as morphometrics, molecular comparisons and ecological analyses. DOI PubMed
58.Gries, G; Schaefer, PW; Gries, R; Liska, J; Gotoh, T. (2001) Reproductive character displacement in Lymantria monacha from northern Japan?Journal of Chemical Ecology 27: 1163-1176 Reproductive character displacement in Lymantria monacha from northern Japan?
Lymantria monacha; Lymantria fumida; Lymantria dispar; diel periodicity; interspecific competition; reproductive character displacement; strain; (7R, 8S)-cis-7,8-epoxy-2-methyloctadecane; (+)-disparlure; (7R, 8S)cis-7,8-epoxy-octadecane; (+)-monachalure; 2-methyl-(Z)-7-octadecene; (Z)-7-octadecene
Our objective was to test the hypothesis that the pheromone blend and/or diel periodicity of pheromonal communication differ in populations of the nun moth, Lymantria monacha (Lepidoptera: Lymantriidae), from eastern Asia (northern Honshu, Japan) and Central Europe (Bohemia, Czech Republic). Coupled gas chromatographic-electroantennographic detection (GC-EAD) analyses of pheromone gland extract of female L monacha from Japan confirmed the presence of compounds previously identified in pheromone extracts of L. monacha from Bohemia, as follows: (Z)-7-octadecene, 2-methyl-(Z)-7-octadecene (2me-Z7-18Hy), cis-7,8-epoxy-octadecane (monachalure), and cis-7,8-epoxy-2-methyloctadecane (disparlure). Field experiments in Honshu suggested that (+)-monachalure is the major pheromone component of L. monacha. 2me-Z7-18Hy significantly enhanced attractiveness of (+)-monachalure. Addition of (+)-disparlure to (+)-monachalure plus 2me-Z7-18Hy in Honshu and Bohemia increased attractiveness of lures by 1.2 and 20 times, respectively, indicating that (+)-disparlure is of least and most significance in the respective L monacha populations. Moreover, capture of male L. monacha in pheromone-baited traps between 18:00 and 24:00 hr in Bohemia and 2:00 and 5:00 hr in Honshu revealed a markedly different diel periodicity of pheromonal communication. Pheromonal communication late at night and use of (+)-monachalure, rather than (+)-disparlure, as the major pheromone component by L. monacha in Honshu may have resulted from interspecific competition with coseasonal L. fumida, which uses the early night for pheromonal communication and (+)-disparlure as major pheromone component. Whether communication channel divergence of L. monacha in Honshu indeed constitutes a case of reproductive character displacement is difficult to prove. The evolution of such divergence in sympatric populations of L. fumida and L. monacha would have to be demonstrated.
57. Rhainds, M; Lan, CC; King, S; Gries, R; Mo, LZ; Gries, G. (2001) Pheromone communication and mating behaviour of coffee white stem borer, Xylotrechus quadripes Chevrolat (Coleoptera : Cerambycidae).Applied Entomology and Zoology 36: 299-309 Pheromone communication and mating behaviour of coffee white stem borer, Xylotrechus quadripes Chevrolat (Coleoptera : Cerambycidae)
Xylotrechus quadripes; coffee white stem borer; Cerambycidae; pheromone; mating behaviour
This study investigated pheromone communication and mating behaviour of the coffee white stem borer (CWSB), Xylotrechus quadripes (Coleoptera: Cerambycidae), in South Yunan, China. Coupled gas chromatographic-electroantennographic detection (GC-EAD) and GC-mass spectrometric (MS) analyses of volatiles released by male and female CWSB identified 2-hydroxy-3-decanone and 2,3-decanedione as male-specific candidate pheromones. Further GC-EAD and GC-MS analyses confirmed that only (S)-2-hydroxy-3-decanone is produced by male CWSB and elicits antennal responses by male and female CWSB. In field experiments, 2-hydroxy-3-decanone as a trap bait afforded capture of one female CWSB, and in laboratory experiments it weakly attracted female but not male CWSB. Complex mating behaviour in CWSB includes: 1) attraction of potential mates by both sexes; 2) repeated landings (with ever decreasing distance) of a female next to a male; 3) males dashing to a nearby female; 4) rejection of mating attempts by females; 5) post-mating female guarding by males; and 6) size-dependent mating success of males. Considering this complex mating behaviour, lack of direct flight towards pheromone sources, mating near pheromone-baited traps, and only moderate attractiveness of (synthetic) pheromone, pheromone-based trapping of females does not seem to be a viable strategy for managing CWSB populations in China.
54. Takacs, S; Gries, G; Gries, R. (2001) Communication ecology of webbing clothes moth: 4. Identification of male- and female-produced pheromones.Chemoecology 11: 153-159 Communication ecology of webbing clothes moth: 4. Identification of male- and female-produced pheromones
Tineola bisselliella; Lepidoptera; Tineidae; aggregation pheromone; sex pheromone; gas chromatographic-electroantennographic detection; GC-EAD; (Z)-9-hexadecenoic acid methyl ester; hexadecanoic acid methyl ester; octadecanoic acid methyl ester; (E,Z)-2,13-octadecadienal; (E,Z)-2,13-octadecadienol
We investigated the hypothesis that aggregation signals produced by male webbing clothes moths (WCM), Tineola bisselliella (Hum.) (Lepidoptera: Tineidae), and close-range male attractant signals produced by females have a pheromonal basis, at least in part. Gas chromatographic-electroantennographic detection (GC-EAD) and GC-mass spectrometric analyses of bioactive methanolic extracts of male WCM disclosed three candidate pheromone components: hexadecanoic acid methyl ester (16:Ester), (Z)-9-hexadecenoic acid methyl ester (Z9-16:Ester), and octadecanoic acid methyl ester (18:Ester). In bioassay experiments in a large Plexiglas (TM) arena, a blend of synthetic 16:Ester plus Z9-16:Ester was attractive to male and virgin (but not mated) female WCM; the 18:Ester was inactive. GC-EAD analyses of pheromone gland extracts from female WCM revealed (E,Z)-2,13-octadecadienal (E2Z13-18:Ald) and (E,Z)-2,13-octadecadienol (E2Z13-18:OH) as candidate sex pheromone components. In arena bioassay experiments, 1 - 5 female equivalents of synthetic E2Z13-18:Ald (0.2 ng) and E2Z13-18:OH (0.1 ng) were more attractive to male WCM than were two virgin female WCM. We anticipate that the combination of aggregation and sex pheromones, male-produced sonic aggregation signals, and habitat-derived semiochemicals will be highly effective in attracting male and female WCM to commercial traps.
53. Takacs, S; Gries, G; Gries, R. (2001) Communication ecology of webbing clothes moth: 1. Semiochemical-mediated location and suitability of larval habitat.Journal of Chemical Ecology 27: 1535-1546 Communication ecology of webbing clothes moth: 1. Semiochemical-mediated location and suitability of larval habitat
Tineola bisselliella; Lepidoptera; Tineidae; semiochemicals; larval-habitat location; host-habitat location; dietary requirements; fitness; larval development; untanned animal pelts; fur
We tested two hypotheses: 1) that there is semiochemical-mediated attraction of male and female webbing clothes moth (WCM), Tineola bisselliella (Hum.) (Lepidoptera: Tineidae) to suitable larval habitat, and 2) that selection of optimal larval habitat has fitness consequences. In binary or ternary choice arena bioassay experiments that prevented WCM from contacting test stimuli, males and females were attracted to dried but untanned animal pelts (red squirrel, muskrat, beaver, coyote, red fox and bobcat) and preserved horseshoe crab but not to unprocessed sheep's wool, demonstrating semiochemical-based recognition of, and discrimination between, potential larval habitats. Selection of habitat has fitness consequences for ovipositing females, because significantly more male and female WCM completed development when the larval diet consisted of intact animal pelt (hide plus hair) rather than hide or hair alone. Equal attraction of male WCM to muskrat pelt volatiles in Porapak Q or solvent extracts of muskrat pelts indicated that volatile semiochemicals could be obtained by both methods.
52. Takacs, S; Gries, G; Gries, R. (2001) Communication ecology of webbing clothes moth: 2. Identification of semiochemicals mediating attraction of adults to larval habitat.Journal of Chemical Ecology 27: 1547-1560 Communication ecology of webbing clothes moth: 2. Identification of semiochemicals mediating attraction of adults to larval habitat
Tineola bisselliella; Lepidoptera; Tineidae; semiochemicals; larval-habitat location; host-habitat location; nonanal; geranylacetone; coupled; gas chromatographic-electroantennographic detection; GC-EAD
Our objective was to identify the semiochemicals that mediate attraction of the webbing clothes moth (WCM), Tineola bisselliella (Lepidoptera: Tineidae), to suitable larval habitat. Coupled gas chromatographic-electroantennographic detection (GC-EAD) analyses of Porapak Q-captured bioactive volatiles from horseshoe crab, and dried but untanned vertebrate pelts revealed numerous EAD-active volatiles. These volatiles were identified by comparative GC-mass spectrometry and GC-EAD analyses of natural and synthetic compounds. A blend of 28 synthetic candidate semiochemicals attracted both male and female WCM. Experiments deleting various components determined that saturated aldehydes-but not unsaturated aldehydes, saturated hydrocarbons, saturated alcohols, or ketones-were essential for blend attractiveness. A blend of nonanal, the single most attractive aldehyde, in combination with geranylacetone was more attractive to WCM than the 28-component blend or dried, untanned animal pelt. Selection of larval habitat resides more with male than female WCM, as indicated by stronger EAD responses from male than female antennae to habitat-derived semiochemicals, and more selective and early response to habitat cues by males than females. Exploitation of nonanal and geranylacetone as resource-derived semiochemicals by both adult WCM and its larval parasitoid, Apanteles carpatus, is an example of convergent semiochemical parsimony.
51. Giblin-Davis, RM; Gries, R; Crespi, B; Robertson, LN; Hara, AH; Gries, G; O'Brien, CW; Pierce, HD. (2000) Aggregation pheromones of two geographical isolates of the New Guinea sugarcane weevil, Rhabdoscelus obscurus.J. Chem. Ecol. 26: 2763-2780 Aggregation pheromones of two geographical isolates of the New Guinea sugarcane weevil, Rhabdoscelus obscurus
aggregation pheromones; Coleoptera; Curculionidae; cytochrome oxidase I; 2-methyl-4-heptanol; (E2)-6-methyl-2-hepten-4-ol; 2-methyl-4-octanol; mitochondrial DNA; New Guinea sugarcane weevil; palm weevil; Rhabdoscelus obscurus; rhynchophorol; sibling species; sugarcane
The aggregation pheromones were studied from two geographical isolates (Hakalau, Hawaii, and Silkwood, Queensland, Australia) of the New Guinea sugarcane weevil, Rhabdoscelus obscurus. Coupled gas chromatographic-electroantennographic detection (GC-EAD) and GC-mass spectrometric (MS) analyses of Porapak Q volatile extract from male and from female Hawaiian R. obscurus revealed a single EAD-active, male-specific candidate pheromone, which was identified as 2-methyl-4-octanol (1). Corresponding volatile analyses from male and from female Australian R. obscurus consistently revealed three EAD-active, male-specific candidate pheromone components that were identified as 1, (E2)-6-methyl-2-hepten-4-ol (rhynchophorol) (2), and 2-methyl-4-heptanol (3). In field experiment 1 in Hakalau, Hawaii, traps baited with a stereoisomeric mixture of synthetic 1 (3 mg/day) plus sugarcane captured more weevils than did traps baited with 1 or sugarcane alone or no bait, indicating that 1 is the pheromone of the Hawaiian R. obscurus population. In field experiment 2, conducted in Silkwood, Australia. traps baited with stereoisomeric mixtures of synthetic 1, 2. and 3 (3 mg/day each) plus sugarcane caught more weevils than did unbaited traps or traps baited with 1, 2, and 3 or sugarcane. Testing candidate pheromone components 1, 2, and 3 in experiments 2-5 in all possible binary, ternary, and quaternary combinations with sugarcane. indicated that 1 and 2 in combination, but not singly, are pheromone components of the Australian R. obscurus population. Weevils from several locations in Australia and Hawaii could not be differentiated using traditional morphological characters or ultrastructural comparisons with scanning electron microscopy (SEM). However, comparisons of mtDNA sequences (cytochrome oxidase I: regions 11 to M4; 201 base pairs) revealed 5.5% variation between the Hawaiian (N = 2) and the Australian (N = 4) samples. There was no intrapopulation variation in sequence data from the weevils from Hawaii versus Australia, suggesting that they are sibling species. DOI
50.Gries, R; Gries, G; Khaskin, G; King, S; Olfert, O; Kaminski, LA; Lamb, R; Bennett, R. (2000) Sex pheromone of orange wheat blossom midge, Sitodiplosis mosellana.Naturwissenschaften 87: 450-454 Sex pheromone of orange wheat blossom midge, Sitodiplosis mosellana
Pheromone extract of the female orange wheat blossom midge, Sitodiplosis mosellana (Gehin) (SM) (Diptera: Cecidomyiidae), was analyzed by coupled gas chromatographic-electroantennographic detection (GC-EAD) and GC-mass spectrometry (MS), employing fused silica columns coated with DB-5, DB-210, DB-23 or SP-1000. These analyses revealed a single, LAD-active candidate pheromone which was identified as 2,7-nonanediyl dibutyrate. In experiments in wheat fields in Saskatchewan, traps baited with (2S,7S)-2,7-nonanediyl dibutyrate attracted significant numbers of male SM. The presence of other stereoisomers did not adversely affect trap captures. Facile synthesis of stereoisomeric 2,7-nonanediyl dibutyrate will facilitate the development of pheromone-based monitoring or even control of SM populations.
49. McNair, C; Gries, G; Gries, R. (2000) Cherry bark tortrix, Enarmonia formosana: Olfactory recognition of and behavioral deterrence by nonhost angio- and gymnosperm volatiles.Journal of Chemical Ecology 26: 809-821 Cherry bark tortrix, Enarmonia formosana: Olfactory recognition of and behavioral deterrence by nonhost angio- and gymnosperm volatiles
Lepidoptera; Tortricidae; Enarmonia formosana; cherry bark tortrix; kairomone; host selection; foraging behavior; plant volatiles; nonhost volatiles; repellency/inhibition; oviposition deterrence; hexanol; benzyl alcohol; nonanal; decanal; alpha-pinene
We tested the hypothesis that males and females of the cherry bark tortrix (CBT), Enarmonia formosana, antennally perceive and behaviorally respond to volatiles from nonhost plants. Volatiles from flowering cherry trees, Prunus serrulata Kwanzan, and from nonhost trees, including trembling aspen, Populus tremuloides, grand fir, Abies grandis, Norway spruce, Picea abies, and Scots pine, Pinus sylvestris, were captured on Porapak Q and extracts analyzed by coupled gas chromatographic-electroantennographic detection (GC-EAD). Compounds that elicited responses from male and female antennae were identified by coupled CC-mass spectrometry (MS) and by comparative CC-MS and GC-EAD with authentic standards. In field cage and field experiments, nonanal from aspen trees and (+/-)-alpha-pinene from coniferous trees were effective in reducing captures of male CBT in pheromone-baited traps and deterring oviposition by female CBT on cherry blocks. Recognition of nonhost volatiles, such as nonanal and alpha-pinene, may allow male and/or female CBT to avoid trees that provide inadequate concealment from predators during calling, resting, and copulation and that are unsuitable for oviposition and development of offspring. Nonhost volatiles may also be exploited for control of CBT by disrupting both mate- and host-finding.
48. Mistal, C; Takacs, S; Gries, G. (2000) Evidence for sonic communication in the German cockroach (Dictyoptera : Blattellidae).Canadian Entomologist 132: 867-876 Evidence for sonic communication in the German cockroach (Dictyoptera : Blattellidae)
Our objective was to test the hypothesis that late-instar nymph, male, and (or) female German cockroaches, Blattella germanica (L.), use sonic signals for intraspecific communication. A digital-recording system was assembled that consisted of a computer equipped with data-acquisition hardware and software, microphones sensitive to sonic and ultrasonic frequencies, and speakers capable of emitting sonic and ultrasonic sound. Sound was repeatedly recorded from groups of five nymphs, five virgin males, or five virgin females. Click-type sounds were commonly present in recordings from nymphs, and consisted of sound pulses of about 10-ms duration and peak frequencies of 7, 9, 11, and 14 kHz. Similar "clicks" were found in recordings from females. In replicated binary choice arena bioassays with individual laboratory-reared insects, played-back "clicks" from nymphs or females or computer-generated artificial clicks attracted nymphs but not males or females. These results provide the first evidence that sonic signals are part of the complex B. germanica communication system.
47. Morewood, P; Gries, G; Liska, J; Kapitola, P; Haussler, D; Moller, K; Bogenschutz, H. (2000) Towards pheromone-based monitoring of nun moth, Lymantria monacha (L.) (Lep., Lymantriidae) populations.Journal of Applied Entomology-Zeitschrift Fur Angewandte Entomologie 124: 77-85 Towards pheromone-based monitoring of nun moth, Lymantria monacha (L.) (Lep., Lymantriidae) populations
The research objective was to develop pheromone-based monitoring of the nun moth, Lymantria monacha (L.), an important defoliator of spruce and pine forests in central Europe. In 38 spruce or pine forests in central Europe, captures of male L. monacha in nonsaturating Unitraps and saturating Delta sticky traps baited with 0.2, 2, 20, or 200 mu g of the L. monacha (pheromone) volatile blend [(+/-)-disparlure, (+/-)-monachalure, and 2-methyl-Z7-octadecene at a 20:20: 1 ratio] were compared with estimates of population densities obtained by counts of larval faecal pellets, pupal cases, and adult moths resting on tree trunks. Total captures of male L. monacha throughout the flight season in both types of trap were correlated with numbers of larval faecal pellets, irrespective of pheromone dose. Nonsaturating Unitraps baited with 2 mu g of the L. monacha volatile blend seem to provide a cost-effective tool for monitoring densities of L. monacha populations. Long-term testing of this monitoring system has been initiated to substantiate the quantitative relationship between larval populations and trap captures of male L. monacha and to determine the threshold number of captured male moths that indicates an incipient outbreak.
46. Sasaerila, Y; Gries, G; Gries, R; Boo, TC. (2000) Specificity of communication channels in four limacodid moths: Darna bradleyi, Darna trima, Setothosea asigna, and Setora nitens (Lepidoptera : Limacodidae).Chemoecology 10: 193-199 Specificity of communication channels in four limacodid moths: Darna bradleyi, Darna trima, Setothosea asigna, and Setora nitens (Lepidoptera : Limacodidae)
Darna bradleyi; Darna trima; Setothosea asigna; Setora nitens; nettle caterpillars; oil palm; Elaeis guineensis; antagonism; diel periodicity; habitat partitioning; sex pheromone; communication channel; reproductive isolation
Darna bradleyi Holloway, D. trima Moore, Setothosea asigna van Eecke and Setora nitens Walker are sympatric and coseasonal limacodid moths in plantations of oil palm, Elaeis guineensis Jacq. (Arecales: Palmae), in Borneo, southeast Asia. We tested the hypothesis that these four species maintain reproductive isolation through specificity in diel periods of communication, microlocation for communication and/or communication signal (pheromone). Studying diel periodicity of calling behavior by female moths and response by male moths to traps baited with virgin females or synthetic pheromone, we determined that sexual communication of D. bradleyi and D. trima took place from similar to 17:30 to 18:45 hr and that of S. asigna and S. nitens from similar to 18:45 to 20:00 hr and from similar to 18:30 to 19.30 hr, respectively. Over 80% of male S, asigna and S. nitens were captured in pheromone-baited traps suspended >5 m high, whereas male D. bradleyi and D. trima were captured mostly in traps < 5 m high. Synthetic pheromone baits attracted male moths in a species-specific manner. Moreover, baits containing both S. asigna and S. nitens pheromones failed to attract any male moths, indicating that female S. asigna and S. nitens, with overlapping communication periods, use bifunctional pheromone components that attract conspecific males while repelling heterospecifics. Similarly, addition of D. bradleyi pheromone to S. asigna or S. rnitens pheromone reduced attraction of male S. asigna and S. nitens. The failure of D. bradleyi and D. trima, which overlap in time and microlocation for communication, to evolve bifunctional pheromones may be attributed to the recent occurrence of sympatry between D. bradleyi and D. trima in Borneo, apparently too recent for bifunctional pheromones to have evolved. We conclude that D, br bradleyi, D. trima, S. asigna and S. nitens utilize any or all of diel periodicity, intra and interspecific effects of communication signal and/or microlocation for signaling, allowing these limacodids to co-inhabit the same habitat and remain reproductively isolated.
45. Sasaerila, Y; Gries, R; Gries, G; Khaskin, G; Hardi. (2000) Sex pheromone components of nettle caterpillar, Setora nitens.Journal of Chemical Ecology 26: 1983-1990 Sex pheromone components of nettle caterpillar, Setora nitens
Setora nitens; Setothosea asigna; nettle caterpillar; Limacodidae; Lepidoptera; sex pheromone; (Z)-9-dodecenal; (Z)-9,11-dodecadienal; (E)-9-dodecenal; (E)-9,11-dodecadienal; oil palm; Elaeis guineensis
Gas chromatographic-electroantennographic detection (GC-EAD) analyses of pheromone gland extracts of Female nettle caterpillars, Setora nitens, revealed four compounds that consistently elicited responses from male moth antennae. Retention indices on three fused silia columns (DB-5, DB-23, and DB-210) of two EAD-active compounds were almost identical to those of (E)-9-dodecenal (E9-12: Aid) and (E)-9,11-dodecadienal (E9,11-12: Aid), two pheromone components previously identified in congeneric Setothosea asigna. However, comparative GC, CC-EAD, and GC-mass spectrometry of extracted S. nitens compounds and authentic standards revealed that the candidate pheromone components were (Z)-9-dodecenal (Z9-12:Ald) and (Z)-9,11-dodecadienal (Z9,11-12:Aid). The two other EAD-active compounds in pheromone gland extracts proved to be the corresponding alcohols to these aldehydes. In field-trapping experiments in Tawau, Malaysia, synthetic Z9-12:Ald and Z9,11-12:Ald at a 1:1 ratio, but not singly, attracted male S. nitens. Attractiveness of these two aldehydes could not be enhanced through the addition of their corresponding alcohols. Whether these differences in pheromone biology and chemistry between S. nitens and S. asigna are sufficient to prevent cross-attraction of heterospecific males or whether nonpheromonal mechanisms are required to maintain reproductive isolation is currently being studied.
44. Sasaerila, Y; Gries, R; Gries, G; Khaskin, G; King, S; Boo, TC. (2000) Decadienoates: Sex pheromone components of nettle caterpillars Darna trima and D-bradleyi.Journal of Chemical Ecology 26: 1969-1981 Decadienoates: Sex pheromone components of nettle caterpillars Darna trima and D-bradleyi
Lepidoptera; Limacodidae; Darna trima; Darna bradleyi; Setothosea asigna; Setora nirens; nettle caterpillars; oil palm; sex pheromone; 2-methylbutyl (E)-7,9-decadienoate; (E)-2-hexenyl (E)-7,9-decadienoate; methyl (E)-7,9-decadienoate; isobutyl (E)-7,9-decadienoate; (E)-9-dodecenal; (E)-9,11-dodecadienal; (Z)-9-dodecenal; (Z)-9,11-dodecadienal
This study was undertaken to identify sex pheromone components of nettle caterpillars Darna trima and Darna bradleyi (Lepidoptera: Limacodidae) whose larvae defoliate oil palm, Elaeis guineensis, in southeast Asia. Coupled gas chromatographic-electroantennographic detection (GC-EAD) analyses of pheromone gland extracts revealed two antennally active compounds produced by female D. trima and two by female D. bradleyi. Molecular structures of these candidate pheromone components were identified by electron-impact and chemical-ionization mass spectrometry; retention-index calculations on DB-5, DB-23, and DB-210 columns; microanalytical treatments, as well as syntheses of "auxilliary" compounds that facilitated identification of the compounds. The compounds from D. trima were 2-methylbutyl (E)-7,9-decadienoate (A) and (E)-2-hexenyl (E)-7,9-decadienoate (B); from D. bradleyi we identified methyl (E)-7,9-decadienoate (C), and isobutyl (E)-7,9-decadienoate (D). In field experiments in Malaysia, (S)-2-methylbutyl (E)-7,9-decadienoate (SA) in combination with B proved to be essential and synergistic pheromone components for attraction of male D. trima. (R)-2-Methylbutyl (E)-7,9-decadienoate (RA) had no behavioral activity. Compound D singly attracted male D. bradleyi, but addition of C to D at a 1:10 ratio significantly enhanced attractiveness of the bait. Synthetic pheromone blends were more effective trap baits than unmated female moths and could be developed for monitoring populations of D. trima and D. bradleyi in Asian oil palm plantations.
43. DeLury, NC; Gries, G; Gries, R; Judd, GJR; Brown, JJ. (1999) Sex pheromone of Ascogaster quadridentata, a parasitoid of Cydia pomonella.Journal of Chemical Ecology 25: 2229-2245 Sex pheromone of Ascogaster quadridentata, a parasitoid of Cydia pomonella
sex pheromone; parasitoid; Ascogaster quadridentata; Cydia pomonella; (Z,Z)-9,12-octadecadienal; (Z)-9-hexadecenal; 3,7,11-trimethyl-6E,10-dodecadienal; dihydrofarnesal; Braconidae; Tortricidae
Porapak Q volatile extracts of female Ascogaster quadridentata, an egg-larval endoparasitoid of codling moth, Cydia pomonella, bioassayed in Y-tube olfactometers attracted male, but not female, A. quadridentata. Coupled gas chromatographic-electroantennographic detection (GC-EAD)analysis of bioactive extracts revealed three compounds that elicited responses by male A. quadridentata antennae. CC-mass spectra (MS) indicated, and comparative analyses of authentic standards confirmed, that these compounds were (Z,Z)-9,12-octadecadienal, (Z)-9-hexadecenal, and 3,7,11-trimethyl-6E,10-dodecadienal. (Z,Z)-9,12-Octadecadienal alone attracted laboratory-reared male A. quadridentata in Y-tube olfactometer and field-cage bioassays, and attracted feral A. quadridentata in a field experiment. This sex pheromone could be used to help detect populations of A. quadridentata, delineate their distributions, and determine potential sources of parasitoids for capture and release in integrated programs for control of C pomonella.
42. DeLury, NC; Gries, R; Gries, G; Judd, GJR; Khaskin, G. (1999) Moth scale-derived kairomones used by egg-larval parasitoid Ascogaster quadridentata to locate eggs of its host, Cydia pomonella.Journal of Chemical Ecology 25: 2419-2431 Moth scale-derived kairomones used by egg-larval parasitoid Ascogaster quadridentata to locate eggs of its host, Cydia pomonella
kairomone; parasitoid; Ascogaster quadridentata; Cydia pomonella; host location; foraging behavior; courtship displays; wing fanning; heptanal; octanal; nonanal; decanal; undecan-2-one; dodecanal; pentadecan-2-one; (Z)-6-pentdecen-2-one; (Z)-9-hexadecenal; (Z)-6-heptadecen-2-one; and 3,7,11-trimethyl-2E,6E,10-dodecatrien-1-ol acetate
We determined that location of host (Cydia pomonella) eggs by Ascogaster quadridentata is mediated by kairomones, investigated potential sources of the kairomones and identified a blend of kairomones from the source that was attractive to A. quadridentata. In Y-tube olfactometer bioassays, female A. quadridentata were attracted to Porapak Q-collected Volatiles from female C. pomonella scales and eggs, but not to C. pomonella sex pheromone. Scales of C. pomonella were also attractive to male A. quadridentata. Coupled gas chromatographic-electroantennographic detection analysis of scale volatile extracts revealed numerous compounds that elicited responses from male or female A. quadridentata antennae, including heptanal, octanal, nonanal, decanal, undecan-2-one, dodecanal, pentadecan-2-one, (Z)-6-pentadecen-2-one, (Z)-9-hexadecenal, (Z)-6-heptadecen-2-one, and 3,7,11-trimethyl-2E,6E,10-dodecatrien-1-ol acetate. A synthetic blend of these compounds at quantities and ratios equivalent to Porapak Q scale volatile extract was attractive to female A. quadridentata in a Y-tube olfactometer bioassay.
41.Gries, G; Clearwater, J; Gries, R; Khaskin, G; King, S; Schaefer, P. (1999) Synergistic sex pheromone components of white-spotted tussock moth, Orgyia thyellina.Journal of Chemical Ecology 25: 1091-1104 Synergistic sex pheromone components of white-spotted tussock moth, Orgyia thyellina
Lepidoptera; Lymantriidae; white-spotted tussock moth; Orgyia thyellina; (Z)-6-heneicosen-11-one; (Z)-6-heneicosen-9-one; (Z)-6,(E)-8-heneicosadien-11-one; sex pheromone; synergism; quarantine insect; international trade; eradication; Bacillus thuringiensis; microbial insecticide
In 1996, the exotic white-spotted tussock moth (WSTM), Orgyia thyellina (Lepidoptera: Lymantriidae), was discovered in Auckland, New Zealand. Because establishment of WSTM would threaten New Zealand's orchard industry and international trade, eradication of WSTM with microbial insecticide was initiated To monitor and complement eradication of WSTM by capture of male moths in pheromone-baited traps, pheromone components of female WSTM needed to be identified. Coupled gas chromatographic-electroantennographic detection analysis of pheromone gland extract revealed several compounds that elicited responses from male moth antennae. Mass spectra of the two most EAD-active compounds suggested, and comparative GC-MS of authentic standards confirmed, that they were (Z)-6-heneicosen-11-one (Z6-11-one) and (Z)-6-heneicosen-9-one, the latter termed here "thyellinone." In field experiments in Japan, Z6-11-one plus thyellinone at a 100:5 ratio attracted WSTM males, whereas either ketone alone failed to attract a single male moth. Addition of further candidate pheromone components did not enhance attractiveness of the binary blend. Through the 1997-1998 summer, 45,000 commercial trap lures baited with 2000 mu g of Z6-11-one and 100 mu g of thyellinone were deployed in Auckland towards eradication of the residual WSTM population.
40.Gries, G; Gries, R; Schaefer, PW; Gotoh, T; Higashiura, Y. (1999) Sex pheromone components of pink gypsy moth, Lymantria mathura.Naturwissenschaften 86: 235-238 Sex pheromone components of pink gypsy moth, Lymantria mathura
Pheromone extract of female pink gypsy moth, Lymantria mathura, was analyzed by coupled gas chromatographic-electroantenno-graphic detection (GC-EAD) and coupled CC-mass spectrometry (MS), employing fused silica columns coated with DB-5, DB-210, or DB-23 and a custom-made GC column that separated enantiomers of unsaturated epoxides. These analyses revealed (9R, 10S)-cis-9,10-epoxy-Z3,Z6-nonadecadiene [termed here (+)-mathuralure] and (9S, 10R)-cis-9,10-epoxy-Z3,Z6-nonadecadiene [termed here (-)-mathuralure] at a 1:4 ratio as major candidate pheromone components. In field experiments in northern Japan (Morioka, Iwate Prefecture and Bibai, Hokkaido Prefecture), (+)- and (-)-mathuralure at a ratio of 1:4, but not 1:1 or singly, were attractive to male L. mathura. This is the first demonstration that attraction of male moths required the very same ratio of pheromone enantiomers as produced by conspecific females. Whether L, mathura employ different blend ratios in different geographic areas, and the role of five additional candidate pheromone components identified in this study remains to be investigated.
39.Gries, G; Schaefer, PW; Khaskin, G; Hahn, R; Gries, R; Chao, JT. (1999) Sex pheromone components of Casuarina moth, Lymantria xylina.Journal of Chemical Ecology 25: 2535-2545 Sex pheromone components of Casuarina moth, Lymantria xylina
Lepidoptera; Lymantriidae; Lymantria xylina; Lymantria dispar; Lymantria monacha; Lymantria fumida; sex pheromone; reproductive isolation; (7R,8S)-cis-7,8-epoxy-2-methyleicosane; (7S,8R)-cis-7,8-epoxy-2-methyleicosane; 2-methyl-Z7-eicosene; (7R,8S)-cis-7,8-epoxy-2-methylnonadecane; (7S,8R)-cis-7,8-epoxy-2-methylnonadecane; (7R,8S)-cis-7,8-epoxy-3-methyl-nonadecane; (7S,8R)-cis-7,8-epoxy-3-methylnonadccane; disparlure
cis-7,8-Epoxy-2-methyleicosane is a sex pheromone component of the Casuarina moth, Lymantria xylina Swinhoe. The compound was extracted from pheromone glands of female moths and was identified by coupled gas chromatographic-electroantennographic detection (GC-EAD) and GC-mass spectrometry. In field experiments in Taiwan, traps baited with either or both of (7R,8S)-cis-7,8-epoxy-2-methyleicosane (>99% eel [termed here (+)-xylinalure] and (7S,8R)-cis-7,8-epoxy-2-methyleicosane (>99% eel [termed here (-)-xylinalure] captured male L. xylina. Addition of further candidate pheromone components to xylinalure did not enhance its attractiveness. Demonstration of whether or not female L. xylina produce both optical isomers of xylinalure, and determination of the ratio, will require pheromone extract analyses on a chiral, enantiomer-separating column (as yet unavailable) or derivatization of epoxides in accumulated gland extracts. Attraction of male L. xylina to either enantiomer of xylinalure contrasts with enantiospecific production of, and/or response to, epoxy pheromones in congeners. With no other nocturnal lymantriid moth known in Taiwan to utilize xylinalure for pheromonal communication, enantiospecific "fine tuning" of xylinalure, or evolution of a more complex pheromone blend, may not have been necessary for L. xylina to maintain specificity of sexual communication. Racemic xylinalure will be appropriate for pheromone-based detection surveys of L, xylina in North America.
38. McNair, C; Gries, G; Gries, R. (1999) Sex pheromone components of Enarmonia formosana (Clepidoptera : Tortricidae).Canadian Entomologist 131: 85-92 Sex pheromone components of Enarmonia formosana (Clepidoptera : Tortricidae)
(E)-9-Dodecenyl acetate (E9-12:OAc) and (Z)-9-dodecenyl acetate (Z9-12:OAc) are major components of the sex pheromone of the cherry bark tortrix (CBT), Enarmonia formosana (Scopoli), in British Columbia. The compounds were identified in extracts of female pheromone glands by coupled gas chromatographic electroantennographic detection (GC-EAD) and coupled GC - mass spectrometry. In field experiments, traps baited with E9-12:OAc or Z9-12:OAc singly were unattractive to male CBT, but in combination at ratios of 50:50 or 40:60 captured numerous males. Increasing quantities of this two-component pheromone blend resulted in increasing captures of male CBT. This binary blend at a IO-mg dose caught more CBT males that did caged virgin CBT females. Eight other EAD-active acetates identified in extracts of pheromone glands failed to enhance attractiveness of the pheromone blend. These compounds may serve to reduce cross-attraction of heterospecific male moths or may play a role in courtship behaviour. Formulations of synthetic pheromone are being evaluated for management of the CBT using mass trapping or disorientation of male-CBT moths.
37. McNair, C; Gries, G; Sidney, M. (1999) Toward pheromone-based mating disruption of Enarmonia formosana (Lepidoptera : Tortricidae) on ornamental cherry trees.Canadian Entomologist 131: 97-105 Toward pheromone-based mating disruption of Enarmonia formosana (Lepidoptera : Tortricidae) on ornamental cherry trees
The potential for pheromone-mediated mating disruption of the cherry bark tortrix (CBT), Enarmonia formosana (Scopoli), was evaluated by attaching PVC tube dispensers to the trunks of mature (>40 cm diameter at breast height) ornamental cherry trees, Prunus cvs., Lining suburban streets of New Westminster and Vancouver, British Columbia. Dispensers released either a blend of (E)-9-dodecenyl acetate (E9-12:OAc, 49.5%), (Z)-9-dodecenyl acetate (Z9-12:OAc, 49.5%), and (2)-7-decenyl acetate (Z7-10:OAc, 1%) at a rate of 29 mg/day (Exp. 1), or E9-12:OAc alone at 27 mg/day (Exp. 2), 4 mg/day (Exp. 3), or 0.5 mg/day (Exp. 4). A sticky Delta trap baited with a grey rubber septum impregnated with CBT pheromone components E9-12:OAc (40 mu g), Z9-12:AOc (60 mu g), and Z7-10:OAc (1 mu g) was placed in each tree. Captures of male CBTs in treatment trees were significantly reduced compared with control trees in all experiments. Results suggest that disruption of pheromone-based communication in CBT around individual cherry trees is feasible with a pheromone blend or with E9-12:OAc alone, and could become part of an integrated management strategy for CBT in urban environments.
36. Morewood, P; Gries, G; Haussler, D; Moller, K; Liska, J; Kapitola, P; Bogenschutz, H. (1999) Towards pheromone-based detection of Lymantria monacha (Lepidoptera : Lymantriidae) in North America.Canadian Entomologist 131: 687-694 Towards pheromone-based detection of Lymantria monacha (Lepidoptera : Lymantriidae) in North America
The research objective of this study was to develop a pheromone-based detection system for the nun moth, Lymantria monacha (Linnaeus), an important defoliator of spruce, Picea A. Dietrich, and pine, Pinus Linnaeus (Pinaceae), forests in central Europe. In northeastern Germany, comparative analyses of rubber- and polyurethane-based dispensers impregnated with a 20:20:1 blend of (+/-)-disparlure (cis-7,8-epoxy-2-methyloctadecane), (+/-)-monachalure (cis-7,8-epoxy-octadecane), and 2-methyl-Z7-octadecene revealed that polyurethane-based dispensers afforded higher captures of male L. monacha. Species specificity and optimal dose of the pheromone dispenser were tested in deciduous rather than coniferous forests in central Europe to better reflect nonhabitat settings, such as North American ports, in which detection surveys would be conducted. Baiting Unitraps with 2, 20, 200, or 2000 mu g [based on (+/-)-disparlure] of the L. I,monacha volatile blend resulted in increasing, species-specific captures of male L. monacha with increasing: volatile dose. (+/-)Disparlure, previously used for detection of L. monacha, tested at the same four doses indiscriminately attracted male L. monacha and male Lymantria dispar (Linnaeus). Polyurethane-based dispensers loaded with at least 200 mu g of the L. monacha volatile blend are recommended for sensitive detection surveys of L. monacha in North America.
35. Rhainds, M; Gries, G; Min, MM. (1999) Size- and density-dependent reproductive success of bagworms, Metisa plana.Entomologia Experimentalis et Applicata 91: 375-383 Size- and density-dependent reproductive success of bagworms, Metisa plana
Metisa plana; bagworms; protogyny; pupal mortality; mating success
A study conducted in a Malaysian plantation of oil palm over 5 consecutive generations of bagworms, Metisa plana (Walker) (Lepidoptera: Psychidae), evaluated extent and causes of variability for 3 components of reproductive success: pupal mortality, mating success and fecundity. The population of M. plana in the experimental site exhibited cycles of 70-80 days with discrete generations. Females emerged before males during all generations. Relatively large proportions of M. plana did not reproduce, either because they did not survive as pupa or (for females) mate as adult. Occurrence of unmated female bagworms may be attributed to complex mating procedure, short lifespan of females, limited mating capacity of males, protogyny inducing female-biased operational sex-ratio, and/or flightlessness per se constraining mating success of females. Size attained at pupation is a significant component of reproductive success, with large individuals having greatest survival during pupal stage, mating success and fecundity. Population density also influenced reproductive success of M. plana: female and (to a lesser extent) male larvae on crowded palms attained small size at pupation; survival of pupae was density-dependent during 2 generations for females and density-independent during 5 generations for males; mating success of females was inverse density-dependent during 4 generations. Size- and density-dependent mating success of females may be attributed to mate choice by males, size-dependent pheromone production by and longevity of females, and/or disorientation of mate-seeking males around heavily infested palms. Long-term studies are needed to determine whether and to what extent attributes of oil palm, seasonal fluctuations of abiotic factors and inter-generational variations of reproductive success influence population dynamics of M. plana.
34. Schaefer, PW; Gries, G; Gries, R; Holden, D. (1999) Pheromone components and diel periodicity of pheromonal communication in Lymantria fumida.Journal of Chemical Ecology 25: 2305-2312 Pheromone components and diel periodicity of pheromonal communication in Lymantria fumida
Lepidoptera; Lymantriidae; Lymantria fumida; Lymantria monacha; nun moth; sex pheromone; periodicity; calling behavior; reproductive isolation; disparlure; (7R,8S)-cis-7,8-epoxy-2-methyloctadecane (7S,8R)-cis-7,8-epoxy-2-methyloctadecane; 2-methyl-Z7-octadecene; (7R,8S)-cis-7,8-epoxy-octadecane; (+)-monachalure
Extracts of pheromone glands from female Lymanitria furnida were analyzed by coupled gas chromatographic-electroantennographic detection (GC-EAD) and by coupled GC-mass spectrometry (MS). The two compounds that elicited responses from male L. furnida antennae were identified as cis-7,8-epoxy-2-methyloctadecane (disparlure) and 2-methyl-Z7-octadecene (2me-Z7-18Hy). Field experiments in northern Japan demonstrated that synthetic (7R,8S)-cis-7,8-epoxy-2-methyloctadecane [(+)-disparlure] and 2me- Z7-18Hy are synergistic sex pheromone components of L. fumida. (7S,8R)cis-7,8-Epoxy-2-methyloctadecane [(-)-disparlure] had no behavioral effect on male L. fumida. Traps baited with (+)-disparlure and 2me-Z7-18Hy captured male L. fumida between 21:00 and 24:00 hr, whereas traps baited with (+)-monachalure [(7R,8S)-cis-7,8-epoxy-octadecane],(+)-disparlure and 2me-Z7-18Hy attracted males of the nun moth, L. monacha L., between 02:00 and 04:00 hr. Both temporal separation of pheromonal communication and specificity of pheromone blends seem to contribute to the reproductive isolation of sympatric and coseasonal L. fumida and L. monacha.
33. Blatt, SE; Borden, JH; Pierce, HD; Gries, R; Gries, G. (1998) Alarm pheromone system of the western conifer seed bug, Leptoglossus occidentalis.J. Chem. Ecol. 24: 1013-1031 Alarm pheromone system of the western conifer seed bug, Leptoglossus occidentalis
Leptoglossus occidentalis; western conifer seed bug; Hemiptera : Coreidae; alarm pheromone; metathoracic glands; hexyl acetate; hexanol; hexanal; octyl acetate and heptyl acetate
The alarm pheromones for adult and nymphal western conifer seed bugs, Leptoglossus occidentalis, were collected from the headspace volatiles of agitated bugs and from extracted adult thoraxes and nymphal abdomens. Adult bugs secreted a blend from the metathoracic glands that consisted of hexyl acetate, hexanal, hexanol, heptyl acetate, and octyl acetate (ratio of 152:103:8:1.5:1). Nymphal alarm pheromone produced by the dorsal abdominal glands consisted of (E)-2-hexenal. Agitated adults emitted similar to 24% of the pheromone contained within the glands, while nymphs released similar to 33% of their constitutive supply. The complete blend from both adults and nymphs, tested in a laboratory headspace bioassay, elicited a dispersal (or alarm) response in >70% of individuals tested. Nymphs in the field exposed to synthetic adult or nymphal pheromones, or a mixture of both, responded with >50% dispersing. When single components were tested on adults reared under summer conditions in a forced-air one-way bioassay, hexanal and hexyl acetate, the major components of the secretion, were responsible for eliciting the alarm response. Adults collected in the fall from the field were unresponsive to the tested blend, suggesting that adults seeking aggregation sites in the fall become refractory to alarm pheromone stimuli that would cause aggregations to disperse. The weak dispersal responses elicited in both adults and nymphs by either nymphal or adult pheromones are consistent with a tradeoff in the advantage gained by avoiding predation and the disadvantage of leaving a food source. Because of these weak responses, use of alarm pheromones as pest management tools against L. occidentalis is unlikely. DOI
32. Borden, JH; Wilson, IM; Gries, R; Chong, LJ; Pierce, HD; Gries, G. (1998) Volatiles from the bark of trembling aspen, Populus tremuloides Michx. (Salicaceae) disrupt secondary attraction by the mountain pine beetle, Dendroctonus ponderosae Hopkins (Coleoptera: Scolytidae).Chemoecology 8: 69-75 Volatiles from the bark of trembling aspen, Populus tremuloides Michx. (Salicaceae) disrupt secondary attraction by the mountain pine beetle, Dendroctonus ponderosae Hopkins (Coleoptera: Scolytidae)
semiochemicals; pheromones; disruption; Coleoptera; Scolytidae; Dendroctonus ponderosae; Salicaceae; Populus tremuloides
Coupled gas chromatographic-electroantennographic detection (GC-EAD) analysis of the Porapak Q-captured volatiles from the bark of trembling aspen, Populus tremuloides Michx., revealed four compounds that consistently elicited antennal responses by mountain pine beetles (MPBs), Dendroctonus ponderosae Hopkins. One of these, 1-hexanol, disrupted the capture of MPBs in multiple-funnel traps baited with the aggregation pheromones trans-verbenol and exo-brevicomin and the host kairomone myrcene, a blend of semiochemicals that mediates the secondary attraction response in which beetles mass attack and kill living pines. The other three EAD-active aspen bark volatiles, benzyl alcohol, benzaldehyde and nonanal, were inactive alone, but in binary and ternary combinations contributed to a disruptive effect in an additive and redundant manner when all four aspen bark volatiles were tested in all possible binary and ternary blends. The best ternary blend and the quarternary blend achieved >80% disruption. The quarternary blend enhanced the disruptive effect of the antiaggregation pheromone verbenone in traps, raising the disruptive effect to 98%, and also enhanced the inhibition of attack on attractant-baited lodgepole pines. This is the first demonstration of specific compounds from the bark of angiosperm trees that disrupt the secondary attraction response of sympatric coniferophagous bark beetles. The results support the hypothesis that such bark beetles are adapted to recognize and avoid non-host angiosperm trees by responding to a broad spectrum of volatiles that can act in various blends with equal effect. DOI
31. Ferrao, P; Gries, G; Wimalaratne, PDC; Maier, CT; Gries, R; Slessor, KN; Li, JX. (1998) Sex pheromone of apple blotch leafminer, Phyllonorycter crataegella, and its effect on P-mespilella pheromone communication.J. Chem. Ecol. 24: 2059-2078 Sex pheromone of apple blotch leafminer, Phyllonorycter crataegella, and its effect on P-mespilella pheromone communication
Lepidoptera; Gracillariidae; Phyllonorycter crataegella; Phyllonorycter mespilella; sex pheromone; (Z)-10,(Z)-12-tetradecadienyl acetate; (E)-10,(E)-12-tetradecadienyl acetate; (E)-4,(E)-10-dodecadienyl acetate; interspecific effects
(Z)-10,(Z)-12-Tetradecadienyl acetate (Z10,Z12-14:OAc) and (E)-10,(E)-12-tetradecadienyl acetate (E10,E12-14:OAc) are sex pheromone components of the apple blotch leafminer (ABLM), Phyllonorycter crataegella. Compounds extracted from female pheromone glands were identified by coupled gas chromatographic-electroantennographic detection (GC-EAD) analyses, retention index calculations of BAD-active compounds, and by comparative CC-BAD analyses of female ABLM-produced and authentic (synthetic) compounds. In field experiments in apple Malus domestica orchards in Connecticut, Z10,Z12-14:OAc done attracted ABLM males. Addition of E10,E12-14:OAc to 210,Z12-14:OAc at 0.1:10 or 1:10 ratios enhanced attractiveness of the lure. Geometrical isomers Z10,E12- or E10,Z12-14:OAc at equivalent ratios were behaviorally benign and slightly inhibitory, respectively. In field experiments in British Columbia, Z10,Z12-14:OAc plus E10,E12-14:OAc did not attract Phyllonorycter moths, supporting the contention that ABLM is not present in the fruit growing regions of British Columbia. Z10,Z12-14:OAc added to P. mespilella pheromone, (E)-4,(E)10-dodecadienyl acetate, strongly inhibited response by P. mespilella males. Recognition of the ABLM pheromone blend by allopatric P. mespilella males suggests a phylogenetic relationship and previous sympatry of these two Phyllonorycter spp. If pheromonal attraction of ABLM males were reciprocally inhibited by P. mespilella pheromone, a generic Phyllonorycter pheromone blend could be tested for pheromone-based mating disruption of the apple leaf-mining Phyllonorycter guild in North America. DOI
30.Gries, R; Dunkelblum, E; Gries, G; Baldilla, F; Hernandez, C; Alvarez, F; Perez, A; Velasco, J; Oehlschlager, AC. (1998) Sex pheromone components of Diatraea considerata (Heinrich) (Lep., Pyralidae).Journal of Applied Entomology-Zeitschrift Fur Angewandte Entomologie 122: 265-268 Sex pheromone components of Diatraea considerata (Heinrich) (Lep., Pyralidae)
Three aldehydes, (Z)-11-hexadecenal (Z11-16:Ald), (Z)-7-hexadecenal (Z7-16:Ald) and (Z)-13-octadecenal (Z13-18:Ald), in a ratio of 74:23:3 are female-produced sex pheromone components of the pyralid moth, Diatraea considerata (Heinrich). Compounds extracted from pheromone glands were identified by coupled gas chromatographic-electroantennographic detection (GC-EAD) and coupled CC-mass spectrometry (MS). In field trapping experiments, Z11-16:Aid, Z7-16:Aid or Z13-18:Ald singly were behaviourally inactive, but in ternary combination were as attractive as virgin females. Deleting either Z11-16:Ald or Z7-16:Aid from the ternary aldehyde blend strongly reduced attractiveness indicating that these two compounds are most important for attraction of males. Congeneric and sympatric female D. grandiosella (Dyar) also utilize Z11-16:Aid and Z13-18:Ald as sex pheromone components. Production of Z9-16:Ald by female D. grandiosella and Z7-16:Ald by female D. considerata contributes to the specificity of pheromone blends but does not prevent cross-attraction of heterospecific males. In sugarcane plantations, aldehyde (Z11-16:Ald, Z7-16:Ald and Z13-18:Ald)-impregnated lures may replace females as trap baits to monitor population densities of D. considerata.
29. Macias-Samano, JE; Borden, JH; Gries, R; Pierce, HD; Gries, G; King, GGS. (1998) Primary attraction of the fir engraver, Scolytus ventralis.J. Chem. Ecol. 24: 1049-1075 Primary attraction of the fir engraver, Scolytus ventralis
semiochemicals; primary attraction; kairomones; Scolytus ventralis; Thanasimus undatulus; Abies grandis; monoterpenes; sesquiterpenes
In laboratory bioassays, Porapak Q-captured and steam-distilled volatiles from the bark of host trees, Abies grandis, particularly from root-rot-infected trees, attracted 50-70 % of male and female fir engravers, Scolytus ventralis. Gas chromatographic-electroantennographic detection (GC-EAD) analyses of Porapak Q-captured bark volatiles revealed 19 EAD-active compounds of which 13 (mostly monoterpenes) were identified by GC-mass spectrometry (GC-MS). In separate field experiments, multiple-funnel traps baited with two blends of these 13 synthetic volatiles released at 280 and 340 mg/24 hr attracted 66 and 93% of the total S. ventralis captured, respectively. The clerid predator, Thanasimus undulatus, also responded strongly to the kairomonal volatiles. Additional experiments produced no evidence for aggregation pheromones in S. ventralis. These included laboratory bioassays and GC and GC-EAD analyses of Porapak Q-captured volatiles from male- and female-infested logs or trees undergoing mass attack in the field, GC analyses and/or bioassays of extracts from female accessory glands, extracted volatiles from emerged, attacking and juvenile hormone-treated beetles of both sexes, and videotape analysis of the behavior of attacking beetles on the bark surface. We argue against the hypothesis of pheromone-mediated secondary attraction in S. ventralis and conclude that the attack dynamics of this species can be explained solely by its sensitive primary attraction response to host volatiles. DOI
28. Maier, CT; Gries, R; Gries, G. (1998) Sex pheromone components of pitch pine looper, Lambdina pellucidaria.Journal of Chemical Ecology 24: 491-500 Sex pheromone components of pitch pine looper, Lambdina pellucidaria
Lepidoptera; Geometridae; Lambdina athasaria; Lambdina fiscellaria; Lambdina pellucidaria; sex pheromone; synergism; 7,11-dimethylheptadecane; 5,11-dimethylheptadecane; 7-methylheptadecane
Two methylated hydrocarbons, 7-methylheptadecane (7) and 7,11-dimethylheptadecane (7,11), are sex pheromone components of female pitch pine looper (PPL), Lambdina pellucidaria. Compounds extracted from the pheromone glands of female moths were identified by coupled gas chromatographic-electroantennographic detection (GC-EAD) and coupled GC-mass spectrometry (GC-MS) in selected ion monitoring mode. In field-trapping experiments, 7 and 7,11 in combination, but not singly, attracted numerous male moths. 5,11-Dimethylheptadecane (5,11) was detected by GC-EAD in female PPL pheromone gland extract, but did not significantly increase attraction of PPL males to 7 plus 7,11. Although 7 was > 10 times more abundant than 7,11 in pheromone gland extracts, traps baited with synthetic 7 plus 7,11 at a blend ratio of 1:1, rather than 1:0.1 or 1:0.01, captured the most PPL males. The chemical communication of PPL and spring hemlock looper (SHL), Lambdina athasaria, is strikingly similar. Both species employ 7 plus 7,11 as sex pheromone. Restriction of SHL to forests with eastern hemlock or balsam fir and PPL to forests with pitch or other hard pines contributes to their reproductive isolation. PPL and SHL may also use different optical isomers of enantiomeric 7 and stereoisomeric 7,11 to maintain specificity of their chemical communication.
27. Rhainds, M; Gries, G; Saleh, A. (1998) Density and pupation site of apterous female bagworms, Metisa plana (Lepidoptera : Psychidae), influence the distribution of emergent larvae.Canadian Entomologist 130: 603-613 Density and pupation site of apterous female bagworms, Metisa plana (Lepidoptera : Psychidae), influence the distribution of emergent larvae
In an oil palm plantation in northeast Sumatra, Indonesia, we tested the hypotheses that selection of pupation site by female bagworms, Metisa plana (Walker), influences the distribution of emergent larvae, and that internee dispersal by larvae is density dependant. Similar intratree distributions of empty female pupal cases and early instars and significant regressions between numbers of female pupal cases and larvae per leaf for 36 out of 39 palms indicated that larvae generally remain on the same leaf where they emerged. Proportions of early instars per female pupal case decreased with increasing densities of female pupal cases per tree and were greater on trees surrounding most heavily infested palms, suggesting that intearee dispersal of early instars is density dependent. Interspecific comparisons of life history constraints between M. plana and the allopatric bagworm Oiketicus kirbyi (Guilding) reveal different selective pressures that may have converged and favoured the development of an identical life history trait.
26. Savoie, A; Borden, JH; Pierce, HD; Gries, R; Gries, G. (1998) Aggregation pheromone of Pityogenes knechteli and semiochemical-based interactions with three other bark beetles.Journal of Chemical Ecology 24: 321-337 Aggregation pheromone of Pityogenes knechteli and semiochemical-based interactions with three other bark beetles
Pityogenes knechteli; Ips; Scolytidae; ipsenol; ipsdienol; pheromone; semiochemical; chirality; interspecific interaction
Gas chromatographic-electroantennographic detection and GC-mass spectrometric analyses of volatile extracts from male and female Pityogenes knechteli Swaine identified hexanol, (+/-)-ipsdienol, and (S)-(-)-ipsenol as male-produced candidate pheromone components. In a lodgepole pine, Pinus contorta var. latifolia Engelmann, forest in the southern interior of British Columbia, multiple-funnel traps baited with (+/-)-ipsdienol alone, (S)-(-)-ipsenol alone, or both caught 60%, 6%, and 23%, respectively, of all P. knechteli trapped; unbaited traps caught the remaining 11%. In another field trapping experiment, (S)-(+)-ipsdienol was as attractive as (+)-ipsdienol, and (R)-(-)-ipsdienol was behaviorally benign. (S)-(+)-Ipsdienol is thus concluded to be the principal aggregation pheromone component of P. knechteli. At low release rates, hexanol increased attraction of beetles to (+/-)-ipsdienol, or to (+/-)-ipsidienol plus (S)-(-)-ipsenol, but at high release rates hexanol decreased attraction, suggesting a role in preventing overpopulation in the host tree. On the basis of laboratory bioassays in which walking beetles were attracted to (S)-(-)-ipsenol, we hypothesize that (S)-(-)-ipsenol serves as a short-range attractant for P. knechteli. Three sympatric scolytids were also captured in field experiments as follows: the pine engraver, Ips pini (Say), to its pheromone (+/-)-ipsdienol; I. latidens LeConte to its pheromone (S)-(-)-ipsenol; and I. mexicanus (Hopkins), for which the pheromone is unknown, to (S)-(-)-ipsenol with (+/-)-ipsdienol. Although all four species attack lodgepole pine, we have never observed I. latidens or I. mexicanus attacking the same hosts at P. knechteli or I. pini. These results suggest that ipsenol and ipsdienol serve as synomones involved in promoting aggregation on the host tree, maintaining species-specific communication, and thus contributing to resource partitioning and reduced competition among the four species.
25. GiblinDavis, RM; Gries, R; Gries, G; PenaRojas, E; Pinzon, I; Pena, JE; Perez, AL; Pierce, HD; Oehlschlager, AC. (1997) Aggregation pheromone of palm weevil, Dynamis borassi.J. Chem. Ecol. 23: 2287-2297 Aggregation pheromone of palm weevil, Dynamis borassi
aggregation pheromone; Bursaphelenchus cocophilus; coconut; Cocos nucifera; Coleoptera; Curculionidae; Dynamis borassi; 4-methyl-5-nonanol; palm weevils; red ring disease; red ring nematode
4-Methyl-5-nonanol (1) is the male-produced aggregation pheromone of the palm weevil, Dynamis borassi (F.) from Colombia. The pheromone was identified by coupled gas chromatographic-electroantennographic detection (GC-EAD) analysis of male-and female-produced volatiles, and comparative GC-mass spectrometry (MS) of weevil-produced 1. In field experiments in Colombia, traps baited with a stereoisomeric mixture of synthetic 1 (3 mg/day) plus sugarcane captured more weevils than traps baited with 1 or sugarcane alone, suggesting that pheromone and plant volatiles are synergistically attractive. Use of a chiral, stereoisomer-separating Cyclodex-B column in GC-EAD and GC-MS analyses revealed that D. borassi males produce, and antennae of males and females respond to (4S,5S)-1. Previously identified palm weevil (Rhynchophorus spp.) aggregation pheromones 5-methyl-4-octanol (cruentol) and 6-methyl-2-hepten-4-ol (rhynchophorol) also elicited antennal responses by D. borassi. In field experiments, D. borassi females were captured equally well in traps baited with sugarcane plus either I, cruentol or rhynchophorol. In contrast. D. borassi males were captured most often in traps baited with sugarcane plus I, Because D. borassi is a potential vector of the red ring nematode that causes the lethal red ring disease of palms, pheromone-based trapping of D. borassi could aid in monitoring or management of red ring disease in commercial palm plantations. DOI
23.Gries, G; Slessor, KN; Gries, R; Khaskin, G; Wimalaratne, PDC; Gray, TG; Grant, GG; Tracey, AS; Hulme, M. (1997) (Z)6,(E)8-heneicosadien-11-one: Synergistic sex pheromone component of Douglas-fir tussock moth, Orgyia pseudotsugata (McDunnough) (Lepidoptera: Lymantriidae).Journal of Chemical Ecology 23: 19-34 (Z)6,(E)8-heneicosadien-11-one: Synergistic sex pheromone component of Douglas-fir tussock moth, Orgyia pseudotsugata (McDunnough) (Lepidoptera: Lymantriidae)
Lepidoptera; Lymantriidae; Orgyia pseudotsugata; tussock moth; (Z)6,(Z)9-heneicosadien-11-one; (Z)6,(E)8-heneicosadien-11-one; (Z)6,(Z)9-heneicosadien-11-one; sex pheromone; synergism
Three candidate sex pheromone components, (Z)6,(Z)9-, (Z)6,(E)8-, and (Z)6,(E)9-heneicosadien-11-one (Z6Z9, Z6E8, and Z6E9) were identified in pheromone gland extracts of female Douglas-fir tussock moths (DFTM), Orgyia pseudotsugata (McDunnough). Their occurrence in subnanogram quantities in extracts and structural conversion during analytical procedures and bioassays complicated chemical identifications. Complete identification required comparative analyses of stereoselectively synthesized and female-produced dienones by coupled gas chromatographic-electroantennographic detection (GC-EAD), high-performance liquid chromatography (HPLC) and coupled GC-mass spectrometry (MS). Determination of the pheromone component was contingent upon an experimental design that minimized structural rearrangement of dienones before and during the field test. In a 40-min field experiment, acetonitrile solutions of each of the above dienones were carried on Dry Ice to traps and were syringed onto cotton release devices below trap lids. In combination with the previously known sex pheromone component of DFTM, (Z)6-heneicosen-11-one (Z6), Z6E8 was the only synergistic dienone and the mixture was highly attractive. Because Z6 by itself attracts seven species of tussock moths (two sympatric with DFTM), a blend of Z6 and Z6E8 may impart specificity to DFTM pheromone communication. In commercial lures, this binary blend may facilitate species-specific, sensitive monitoring and efficacious control by mating disruption of this important forest defoliator.
22.Gries, R; Gries, G; King, GGS; Maier, CT. (1997) Sex pheromone components of the apple leafminer, Lyonetia prunifoliella.J. Chem. Ecol. 23: 1119-1130 Sex pheromone components of the apple leafminer, Lyonetia prunifoliella
Lepidoptera; Lyonetiidae; Lyonetia prunifoliella; Perileucoptera coffeella; Lyonetia clerkella; Leucoptera malifoliella; sex pheromone synergism; 10,14-dimethyloctadec-1-ene; 5,9-dimethyloctadecane; 5,9-dimethylheptadecane
Three methylated hydrocarbons, 10,14-dimethyloctadec-1-ene (10Me14Me-1-ene-18Hy = 5Me9Me-17-ene-18Hy), 5,9-dimethyloctadecane (5Me9Me-18Hy), and 5,9-dimethylheptadecane (5Me9Me-17Hy), are synergistic sex pheromone components of the leafminer Lyonetia prunifoliella. Compounds extracted from female pheromone glands were identified by coupled gas chromatographic-electroantennographic detection (GC-EAD), and one compound, 10Me14Me-1-ene-18Hy also by coupled GC-mass spectrometry. In field trapping experiments, 10Me14Me-1-ene-18Hy 5Me9Me-18Hy, and 5Me9Me-17Hy singly were unattractive to males but in ternary combination attracted numerous male moths. Attractiveness of the three-component blend significantly exceeded that of two-component blends. No attraction of males to pheromone lures without 10Me14Me-1-ene-18Hy indicates that this compound is essential for pheromone communication of L. prunifoliella. Common C-5 and C-9 methyl branches in lyonetiid pheromone hydrocarbons suggest a common biosynthetic pathway; the presence of 5Me9Me-17Hy and 5Me9Me-18Hy in pheromone blends of L. prunifoliella and Leucoptera malifoliella provides evidence for phylogeny of lyonetiid chemical communication. Determination of the stereoisomeric composition is required to completely describe the pheromone blend of L. prunifoliella and to support the hypothesis of phylogenetically related sex pheromones. DOI
20. MaciasSamano, JE; Borden, JH; Pierce, HD; Gries, R; Gries, G. (1997) Aggregation pheromone of Pityokteines elegans.J. Chem. Ecol. 23: 1333-1347 Aggregation pheromone of Pityokteines elegans
semiochemical; secondary attraction; pheromone; Pityokteines elegans; enantiomer; ipsenol; ipsdienol; ipsenone
In laboratory bioassay experiments, the beetles Pityokteines elegans were attracted to volatiles captured from bolts of grand fir, Abies grandis, colonized by P. elegans males. Male-specific volatiles detected by coupled gas chromatographic-electroantennographic detection (GC-EAD) analysis and by CC-mass spectrometry employing a chiral column were: (S)-(-)-ipsenol, (+)- and (-)-ipsdienol, and ipsenone. Field experiments demonstrated that 1:1 combinations of (-)-ipsenol and (+/-)-ipsdienol strongly attracted insects of both sexes to multiple-funnel traps. No beetles were attracted to any of these compounds alone, and both enantiomers of ipsdienol were required with (-)-ipsenol to induce attraction. Ipsenol and ipsdienol are now reported as pheromones of five Pityokteines species. Specificity of semiochemical-based communication between sympatric P. elegans and P. minutus appears to be based on host preference and on the composition and chirality of the pheromone blend. DOI
19. Perez, AL; Campos, Y; Chinchilla, CM; Oehlschlager, AC; Gries, G; Gries, R; GiblinDavis, RM; Castrillo, G; Pena, JE; Duncan, RE; Gonzalez, LM; Pierce, HD; McDonald, R; Andrade, R. (1997) Aggregation pheromones and host kairomones of West Indian sugarcane weevil, Metamasius hemipterus sericeus.J. Chem. Ecol. 23: 869-888 Aggregation pheromones and host kairomones of West Indian sugarcane weevil, Metamasius hemipterus sericeus
Coleoptera; Curculionidae; Metamosius hemipterus sericeus; aggregation pheromones; pheromone chirality; (4S,5S)-4-methyl-5-nonanol; 2-methyl-4-heptanol; sugarcane; ethyl acetate; ethyl propionate; ethyl butyrate
Coupled gas chromatagraphic-electroantennographic detection (GC-EAD) analyses and coupled CC-mass spectrometry (MS) of volatiles produced by male and female West Indian sugarcane weevils (WISW), Metamasius hemipterus sericeus (Oliv.), revealed eight male specific, EAD-active compounds: 3-pentanol (1), 2-methyl-4-heptanol (2), 2-methyl-4-octanol (3), 4-methyl-5-nonanol (4), and the corresponding ketones. In field experiments in Florida, alcohols 1-4 in combination with sugarcane were most attractive, whereas addition of the ketones or replacement of alcohols with ketones significantly reduced attraction. In Costa Rica field experiments testing alcohols 1-4 singly and in all binary, ternary, and quaternary combinations revealed 4 in combination with 2 was the major aggregation pheromone, equally attracting male and female WISW. Stereoisomeric 4 and (4S,5S)-4, the only isomer produced by WISW, were equally attractive. Addition of 4S-, 4R- or (+/-)-2 to (4S,5S)-4 significantly enhanced attraction. Sugarcane stalks in combination with 2 plus 4 (ratio of 1:8) were highly synergistic, whereas EAD-active sugarcane volatiles ethyl acetate, ethyl propionate, or ethyl butyrate only moderately increased attractiveness of the pheromone lure. DOI
18. Rhainds, M; Gries, G; Chew, PS. (1997) Adaptive significance of density-dependent ballooning by bagworm larvae, Metisa plana (Walker) (Lepidoptera : Psychidae).Canadian Entomologist 129: 927-931 Adaptive significance of density-dependent ballooning by bagworm larvae, Metisa plana (Walker) (Lepidoptera : Psychidae)
Experiments conducted in a plantation of oil palms, Elaeis guineensis (Jacquin), infested with bagworms, Metisa plana (Walker), tested the hypotheses that crowding enhances the incidence of larval ballooning and negatively affects the size attained by pupae. Proportions of ballooning larvae increased with increasing densities of larvae per palm. The lengths of bags (and pupal cases) decreased with increasing numbers of bagworms per leaf. Ballooning of larvae from crowded palms is likely adaptive because individuals attaining large size at pupation have proportionately greatest survival, mating success, and fecundity.
16. Sasaerila, Y; Gries, G; Khaskin, G; Greis, R; Hardi. (1997) Identification of sex pheromone components of nettle caterpillar, Setothosea asigna.J. Chem. Ecol. 23: 2187-2196 Identification of sex pheromone components of nettle caterpillar, Setothosea asigna
Setothosea asigna; nettle caterpillar; Limacodidae; Lepidoptera; sex pheromone; (E)-9-dodecenal; (E)-9,11-dodecadienal; oil palm; Elaeis guineensis
Gas chromatographic-electroantennographic detection (GC-EAD) analyses of female nettle caterpillar, Setothosea asigna, pheromone gland extracts revealed seven antennally active compounds. Based on their retention indices on three fused silica columns (DB-5, DB-23, and DB-210), these compounds were hypothesized and, through comparative GC, GC-EAD and GC-mass spectrometry with authentic standards, confirmed to be Delta 10-undecenal, dodecanal, (E)-9-dodecenal (E9-12:Ald), (Z)-9-dodecenal, (E)-9-dodecen-1-ol, (E)-9,11-dodecadienal (E9,11-12: Ald), and (E)-9,11-dodecadienol. E9-12:Ald and E9,11-12:Ald were most abundant in female S, asigna pheromone extracts. In field trapping experiments in Palembang, Indonesia, synthetic E9-12:Ald and E9,11-12:Ald at a 1:1 ratio, but not singly, attracted S. asigna males. Attractiveness of these two aldehydes could not be enhanced further through the addition of their corresponding alcohols and/or other aldehydic candidate pheromone components. Use of E9-12:Ald and E9,11-12:Ald for pheromone-based monitoring of S. asigna populations will require lure formulations that minimize pheromone degradation by ultraviolet radiation and atmospheric oxidation. DOI
15. Takacs, S; Gries, G; Gries, R. (1997) Semiochemical-mediated location of host habitat by Apanteles carpatus (Say) (Hymenoptera: Braconidae), a parasitoid of clothes moth larvae.Journal of Chemical Ecology 23: 459-472 Semiochemical-mediated location of host habitat by Apanteles carpatus (Say) (Hymenoptera: Braconidae), a parasitoid of clothes moth larvae
Apanteles carpatus; Tinea pellionella; Hymenoptera; Braconidae; Lepidoptera; Tineidae; semiochemicals; coupled gas chromatographic-electroantennographic detection; host-habitat location; tritrophic interactions; geranylacetone; nonanal
In Y-tube olfactometer bioassays, adult Apanteles carpatus (Say), were attracted to beaver or rabbit pelts infested with larvae of the casemaking clothes moth (CCM), Tinea pellionella L. Porapak Q-captured volatiles from a CCM-infested beaver pelt were also very attractive, whereas isolated CCM larvae or larval feces were not. Coupled gas chromatographic-electroantennographic detection (GC-EAD) analysis of the Porapak Q volatile extract revealed two compounds that elicited responses by A. carpatus antennae. Coupled CC-mass spectrometry (MS) in electron impact and chemical ionization modes of these compounds indicated, and GC-MS and GC-EAD of authentic standards confirmed, that they were nonanal and geranylacetone. While each compound singly did not attract A. carpatus, a 1:1 blend of both compounds was as attractive as the volatile extract. Because these compounds are host habitat-derived, A. carpatus must be a habitat rather than host specialist, responding to kairomonal indicators of localized and specific habitats such as animal hair or feather. The tritrophic interaction between A. carpatus, its clothes moth hosts and their animal-derived habitats is similar to the well-studied relationship between parasitoids of insect herbivores and their host plant habitats.
14. Borden, JH; Gries, G; Chong, LJ; Werner, RA; Holsten, EH; Wieser, H; Dixon, EA; Cerezke, HF. (1996) Regionally-specific bioactivity of two new pheromones for Dendroctonus rufipennis (Kirby) (Col, Scolytidae).Journal of Applied Entomology-Zeitschrift Fur Angewandte Entomologie 120: 321-326 Regionally-specific bioactivity of two new pheromones for Dendroctonus rufipennis (Kirby) (Col, Scolytidae)
1-Methyl-2-cyclohexen-1-ol (MCOL) was shown for the first time to occur in the frass produced by female spruce beetles, Dendroctonus rufipennis (Kirby). MCOL and 4-methylene-6,6-dimethylbicyclo [3.1.1]hept-2-ene (verbenene) were evaluated in five geographic locations for attractiveness to spruce beetles. In trapping experiments (+/-)- or (+)-MCOL enhanced attraction to a standard blend of alpha-pinene with frontalin in two Alaska locations. (+)-MCOL was attractive and (-)-MCOL inhibitory in south-central British Columbia, and (+)-, (-)- and (+/-)-MCOL were all weakly attractive in one of three experiments in southeastern British Columbia and northern Alberta. Verbenene was attractive only in combination with the standard blend plus MCOL in Alaska. In comparison with the standard bait, tree baits incorporating (+/-)- or (+)-MCOL caused higher numbers of trees to be attacked in the interior Alaska locations and (+)-MCOL had the same effect in south-central British Columbia. Density of attack on attacked trees was unaffected. (+/-)- or (+)-MCOL could improve the operational efficacy of tree baits in Alaska, and (+)-MCOL could be used in southcentral British Columbia. Our results indicate that for wide-ranging scolytid species, operational evaluation of new semiochemicals should be regionally specific.
13. Dunkelblum, E; Mendel, Z; Gries, G; Gries, R; Zegelman, L; Hassner, A; Mori, K. (1996) Antennal response and field attraction of the predator Elatophilus hebraicus (Hemiptera: Anthocoridae) to sex pheromones and analogues of three Matsucoccus spp (Homoptera: Matsucoccidae).Bioorganic & Medicinal Chemistry 4: 489-494 Antennal response and field attraction of the predator Elatophilus hebraicus (Hemiptera: Anthocoridae) to sex pheromones and analogues of three Matsucoccus spp (Homoptera: Matsucoccidae)
Elatophilus hebraicus; Matsucoccus josephi; sex pheromone; kairomone
The predator Elatophilus hebraicus is closely associated with its prey, the pine bast scale, Matsucoccus josephi, and utilizes the M. josephi sex pheromone as a kairomone. Kairomonal activity of E. hebraicus was studied by GC-EAD and field bioassays. The sex pheromone of M. josephi [(2E,5R,6E,8E)-5,7-dimethyl-2,6,8-decatrien-4-one [(R)-E-M.j.] elicited a strong EAD response and attracted large numbers of the predator. The sex pheromone of two allopatric Matsucoccus spp., Matsucoccus feytaudi, (3S,7R,8E,10E)-3,7,9-trimethyl-8,10-dodecadien-6-one [(S,R)-E-M.f.] and Matcucossus matsumurae, (2E,4E,6R,10R)-4,6,10,12-tetramethyl-2,4-tridecadien-7-one [(R,R)-E-M.m.], were also EAD-active and attracted significant numbers of E. hebraicus in the forest. Increasing the lure load of (S,R)-E-M.f. and (R,R)-E-M.m, in order to compensate fur their lower volatility relative to (R)-E-M.j., resulted in similar attraction of E. hebraicus to each of the three pheromones. Other Matsucoccus pheromone stereoisomers displayed no behavioral activity. There was a significant difference in the activity of sex pheromone analogues, (6E/Z,8E)-5,7-dimethyl-6,8-decadien-4-one (52% E + 48% Z, ANLG I) and (6E/Z,8E)-2,4,6-trimethyl-1,6,8-nonatrien-3-one (60% E + 40% Z, ANLG 2). The (E) isomer of ANLG 1 evoked a strong EAD response from E. hebraicus and the mixture of E/Z ANLG 1 attracted the predator in moderate numbers, whereas ANLG 2 was inactive both in EAD and field tests. Conversely, M. josephi males were not attracted to M. feytaudi and M. matsumurae pheromones or pheromone analogues. Cross-activity of E. hebraicus to M. feytaudi and M. matsumurae pheromones may be based on structural similarity of the compounds. Alternatively, E. hebraicus may respond specifically to the pheromones of two allopatric Matsucoccus spp. If true, kairomonal attraction of E. hebraicus to these pheromones may have evolved during speciation of the Matsucoccidae and may have been preserved despite the allopatry of M. josephi, M. feytaudi and M. matsumurae. Copyright (C) 1996 Elsevier Science Ltd
12. Francke, W; Schroder, F; Philipp, P; Meyer, H; Sinnwell, V; Gries, G. (1996) Identification and synthesis of new bicyclic acetals from the mountain pine beetle, Dendroctoaus ponderosae Hopkins (Col: Scol).Bioorganic & Medicinal Chemistry 4: 363-374 Identification and synthesis of new bicyclic acetals from the mountain pine beetle, Dendroctoaus ponderosae Hopkins (Col: Scol)
bicyclic acetals; 5-ethyl-7-methyl-6,8-dioxabicyclo[3.2.1]octane; hydroxybrevicomin; Dendroctonus ponderosae
Head-space volatiles obtained from male mountain pine beetles, Dendroctonus ponderosae, were analyzed by coupled CC-MS and chiral gas chromatography. 5-Ethyl-7-methyl-6,8-dioxabicyclo[3.2.1] (6) was found as a new naturally occurring isomer of brevicomin (1). In addition, several stereoisomers of 7-ethyl-5-methyl-6,8-dioxabicyclo[3.2.1] (11) and 1-(5-methyl-6,8-dioxabicyclo[3.2.1]octyl)ethanol (12) could be identified. Relative and absolute configurations of the compounds were determined by unambiguous syntheses, which are described. Copyright (C) 1996 Elsevier Science Ltd
11. GiblinDavis, RM; Oehlschlager, AC; Perez, A; Gries, G; Gries, R; Weissling, TJ; Chinchilla, CM; Pena, JE; Hallett, RH; Pierce, HD; Gonzalez, LM. (1996) Chemical and behavioral ecology of palm weevils (Curculionidae: Rhynchophorinae).Florida Entomologist 79: 153-167 Chemical and behavioral ecology of palm weevils (Curculionidae: Rhynchophorinae)
aggregation pheromones; behavior; Bursaphelenchus cocophilus; chemical ecology; Dynamis borassi; kairomones; Metamasius hemipterus; nematode; Paramasius distortus; red ring nematode; Rhabdoscelus obscurus; Rhynchophorus spp
Palm weevils in the subfamily Rhynchophorinae (Curculionidae) (Rhynchophorus spp., Dynamis borassi, Metamasius hemipterus, Rhabdoscelus obscurus, and Paramasius distortus) use male-produced aggregation pheromones for intraspecific chemical communication. Pheromones comprise 8, 9, or 10 carbon, methyl-branched, secondary alcohols. (4S,5S)-4-Methyl-5-nonanol (ferrugineol) is the major aggregation pheromone for R. ferrugineus, R. vulneratus, R, bilineatus, M. hemipterus, and D. borassi and a minor component for R. palmarum. (5S,4S)-5-Methyl-4-octanol (cruentol), (3S,4S)-3-methyl-4-octanol (phoenicol), and (4S,2E)-6-methyl-2-hepten-4-ol (rhynchophorol) are the main aggregation pheromones for R. cruentatus, R. phoenicis, and R. palmarum, respectively. Plant kairomones strongly enhance pheromone attractiveness but none of the identified volatiles, such as ethyl acetate, ethyl propionate, or ethyl butyrate are as synergistic as fermenting plant (palm or sugarcane) tissue. Studying orientation behavior of foraging weevils to semiochemical devices helped to design and test traps for weevil capture. Generally, 3 mg per day of synthetic pheromone (with non-natural stereoisomers being benign) plus insecticide-treated plant tissue constitute highly attractive trap baits. Potential exists for pheromone-based mass-trapping of weevils to reduce their populations and the spread of the weevil-vectored red ring disease, for monitoring their population dynamics to facilitate pest management decisions, and for detection and possible interception of non-native weevils at ports of entry.
10. Gray, TG; Shepherd, RF; Gries, G; Gries, R. (1996) Sex pheromone component of the western blackheaded budworm, Acleris gloverana Walsingham (Lepidoptera: Tortricidae).Canadian Entomologist 128: 1135-1142 Sex pheromone component of the western blackheaded budworm, Acleris gloverana Walsingham (Lepidoptera: Tortricidae)
(E)-11,13-Tetradecadienal (E11,13-14:Ald) is the major component of the sex pheromone of the western blackheaded budworm (WEB), Acleris gloverana Walsingham. The compound was identified in extracts of the female's pheromone gland by coupled gas chromatographic - electroantennographic detection (GC-EAD) and coupled GC - mass spectrometry in selected ion monitoring mode. In field experiments, E11,13-14:Ald by itself was attractive, but addition of (Z)-11,13-tetradecadienal doubled trap catches of male WEB. (E)-11,13-Tetradecadienol or (E)-11,13-tetradecadienyl acetate in binary or ternary combination with E11,13-14:Ald did not enhance attractiveness of the bait. In comparative assessments of five different trap designs, Uni-traps appeared to be the most suitable for use in pheromone-based monitoring of populations of WEB.
8. Maganga, ME; Gries, G; Gries, R. (1996) Repellency of various oils and pine oil constituents to house flies (Diptera: Muscidae).Environmental Entomology 25: 1182-1187 Repellency of various oils and pine oil constituents to house flies (Diptera: Muscidae)
Musca domestica; repellents; oils; pine oil; terpenoids; gas chromatographic electroantennographic detection
Comparative repellency of pine, mineral, motor, and silicon oil to house flies, Musca domestica L., was tested. In binary choice bioassays with flies feeding on 20 mu l of watery honey solutions mixed with (treatment) or without (control) 10 mu l of one of the oils under investigation, only pine oil completely suppressed feeding and remained inhibitory even after 24 h. Approaching pine oil-treated honey solution, 95% of flies were repelled at a distance >6 mm from the source. Analysis of pine oil volatiles by coupled gas chromatographic-electroantennographic detection (CC-EAD) analysis revealed 5 antennally active compounds, 4 of which were identified by coupled GC-mass spectrometry as myrcene, p-cymene, gamma-terpinene, and (+/-)-linalool. Treatment of honey solution with pine oil, the 4 compounds singly, or in quaternary combination at 10 mu l each, equally and significantly reduced the number of feeding flies compared with untreated honey solution. At an amount of 1 mu l, only the linalool treatment inhibited feeding. In binary choice experiments hath feeding and oviposition were significantly reduced on linalool-treated sources. Because By maggots naturally develop in and rely on microbe-rich organic sources, gravid females may perceive and avoid potential oviposition sites that are rich in antimicrobial compounds such as linalool.
7. Millar, JG; Knudson, AE; McElfresh, JS; Gries, R; Gries, G; Davis, JH. (1996) Sex attractant pheromone of the pecan nut casebearer (Lepidoptera: Pyralidae).Bioorganic & Medicinal Chemistry 4: 331-339 Sex attractant pheromone of the pecan nut casebearer (Lepidoptera: Pyralidae)
Acrobasis muxvorella; (9E,11Z)-hexadecadienal; (9E,11Z)-pentadecadienal; (9E,11Z,13Z)-hexadecatrienal; (9E,11Z,13E)-hexadecatrienal
A female-produced sex pheromone for the pecan nut casebearer, Acrobasis nuxvorella Neunzig, has been identified from pheromone gland extracts of calling female moths. The compound (9E,11Z)-hexadecadienal [(9E,11Z)-16:Ald] was identified by coupled GC-EAD and retention time matches with a synthetic standard on four capillary GC columns of different polarities. Corroboration of the identification of (9E, 11Z)-16:Ald by other analytical chemistry methods was not possible due to the minute quantities of pheromone extracted (<1 picogram/female). In field studies, gray rubber septa impregnated with 100 mu g of synthetic (9E,11Z)-16:Ald were attractive to male moths, whereas higher and lower doses were less attractive. The homologous (9E,11Z)-15:Ald was also slightly attractive, while the more highly conjugated analogues, (9E,11Z,13Z)- and (9E, 11Z,13E)-16:Ald, were not. Copyright (C) 1996 Elsevier Science Ltd
6. Perez, AL; Gries, R; Gries, G; Oehlschlager, AC. (1996) Transformation of presumptive precursors to frontalin and exo-brevicomin by bark beetles and the West Indian sugarcane weevil (Coleoptera).Bioorganic & Medicinal Chemistry 4: 445-450 Transformation of presumptive precursors to frontalin and exo-brevicomin by bark beetles and the West Indian sugarcane weevil (Coleoptera)
(Z)-6-Nonen-2-one (1) has recently been shown to be the biosynthetic precursor for the aggregation pheromone exo-brevicomin (2) in mountain pine beetle (MPB) males, Dendroctonus ponderosae (Hopkins). We tested the hypotheses that (1) 6-methyl-6-hepten-2-one (3) is the biosynthetic precursor for the aggregation pheromone frontalin (4) in the spruce beetle (SE), Dendroctonus rufipennis (Kirby), and (2) that frontalin and exo-brevicomin are produced from 3 and 1, respectively, only by beetles that utilize them as aggregation pheromones. Exposure of scolytids MPB, SE, pine engraver (PE), Ips pini (Say) and Ips tridens (Mannerheim) and West Indian sugar cane weevil (WISW), Metamasius hemipterus sericeus (Olivier) to deuterio- or protio-3 invariably resulted in the production of deuterio- or protio-4. Similarly, exposure of SE. WISW and I. tridens to 1 resulted in the production of 2. We were unable to demonstrate the presence of 3 in SE volatiles, nor were we able to demonstrate the conversion of 6-methyl-5-hepten-2-one to 3 by SE. Production of enantiomerically enriched frontalin and exo-brevicomin by all the beetles exposed to respective precursors reveals widespread occurrence of nonspecific polysubstrate monooxidases in the Coleoptera. Copyright (C) 1996 Elsevier Science Ltd
5. Perez, AL; Hallett, RH; Gries, R; Gries, G; Oehlschlager, AC; Borden, JH. (1996) Pheromone chirality of Asian palm weevils, Rhynchophorus ferrugineus (Oliv) and R-vulneratus (Panz) (Coleoptera: Curculionidae).Journal of Chemical Ecology 22: 357-368 Pheromone chirality of Asian palm weevils, Rhynchophorus ferrugineus (Oliv) and R-vulneratus (Panz) (Coleoptera: Curculionidae)
Coleoptera; Curculionidae; Rhynchophorus; aggregation pheromone; pheromone chirality; 4-methyl-5-nonanol and 4-methyl-5-nonanone; Asian palm weevils
Production of 4-methyl-5-nonanol, and 4-methyl-5-nonanone by two sympatric Asian palm weevils, Rhynchophorus ferrugineus (Oliv.) and R. vulneratus (Pant.) suggested that enantiospecificity of either compound could impart species specificity of pheromone communication. Weevil-produced, racemic 4-methyl-5-nonanol and 4-methyl-5-nonanone and their stereoselectively synthesized optical isomers were subjected to gas chromatographic-electroantennographic detection (GC-EAD) and GC-mass spectrometry (MS) on a chiral Cyclodex-B column. Only the S,S stereoisomer of 4-methyl-5-nonanol was EAD active and was produced by both R. ferrugineus and R. vulneratus. Production and EAD activity of (S)-4-methyl-5-nonanone exceeded that of its antipode in both weevils. In field experiments in Java, (4S, 5S)-4-methyl-5-nonanol and the stereoisomeric mixture were equally attractive. The 4R,5R stereoisomer was inactive. The corresponding ketone enantiomers neither enhanced nor reduced attraction to (4S,5S)-4-methyl-5-nonanol. Lack of apparent differences between R. ferrugineus and R. vulneratus pheromones suggests that synonomy of both weevils should be considered unless other pre- or postzygotic reproductive isolating mechanisms are disclosed in future studies.
4. Rhainds, M; Gries, G; Chinchilla, C. (1996) Development of a sampling method for first instar Oiketicus kirbyi (Lepidoptera: Psychidae) in oil palm plantations.Journal of Economic Entomology 89: 396-401 Development of a sampling method for first instar Oiketicus kirbyi (Lepidoptera: Psychidae) in oil palm plantations
Oiketicus kirbyi; bagworm; oil palm; sampling
The current study was conducted to develop a cost-effective and reliable method to estimate population densities of Ist-instar bagworms, Oiketicus kirbyi (Guilding), in Costa Rican oil palm plantations. Total numbers of larvae per tree were correlated with numbers on SO, 160, 240, or all (320-360) folioles of all palm leaves. The 1-2 values of these correlations were used to assess the accuracy of population estimates obtained by sampling leaves in different positions within the palm crown or different numbers of folioles per leaf. Larvae were most abundant on apical and subapical folioles of leaves in the upper palm crown, When a limited number of folioles per leaf(SO, 160, or 240) was sampled, leaves in the upper crown provided the most accurate estimates of larval densities per tree. Decreasing accuracy of population estimates from upper to lower leaves resulted from increasing variability of larval proportions from upper to lower leaves. Larval populations of 2 other oil palm defoliators, Opsiphanes cassina (Felder), and Stenoma cecropia (Meyrick), are currently assessed by sampling leaf 17. Sampling O. kirbyi larvae on 160 folioles of leaf 17, in the middle palm crown, may represent an acceptable compromise among cost-efficiency, reliability, and simultaneous assessments of several defoliating caterpillars. Reasonably accurate estimates of larval densities per area obtained in this study by sampling 1 palm per hectare should not be interpreted as a general recommendation for sample size, because the effect of population density on optimal sample size per hectare remains yet to be investigated.
2. Tan, ZX; Gries, R; Gries, G; Lin, GQ; Pu, GQ; Slessor, KN; Li, JX. (1996) Sex pheromone components of mulberry looper, Hemerophila atrilineata butler (Lepidoptera: Geometridae).Journal of Chemical Ecology 22: 2263-2271 Sex pheromone components of mulberry looper, Hemerophila atrilineata butler (Lepidoptera: Geometridae)
(6Z-9S,10R)-epoxy-octadecene; (6Z-9R,10S)-epoxy-octadecene; (3Z,6Z-9S,10R)-epoxy-octadecadiene; (3Z,6Z-9R,10S)-epoxy-octadecadiene; chirality; synergism; mulberry looper; Geometridae
(6Z-9S, 10R)-Epoxy-octadecene (SR-1) and (3Z, 6Z-9S, 10R)epoxy-octadecadiene (SR-2) are sex pheromone components of the mulberry looper (MEL), Hemerophila atrilineata Butler. Compounds extracted from female MBL pheromone glands were identified by coupled gas chromatographic-electroantennographic detection (CC-BAD) and CC-mass spectrometry. In field experiments in China, SR-2, RS-2, or both combined were hardly attractive, but SR-2 in combination with SR-I attracted significant numbers of MBL males. Synergistic behavioral activity of SR-1 plus SR-2, but not of corresponding antipode mixtures, indicates enantiospecificity of MBL pheromone communication. Because blends of racemic and enantiospecific (SR) I plus 2 were similarly attractive, racemic 1 plus 2 may have potential for mass trapping or confusion of MBL males in commercial mulberry plantations.
1. Wilson, IM; Borden, JH; Gries, R; Gries, G. (1996) Green leaf volatiles as antiaggregants for the mountain pine beetle, Dendroctonus ponderosae Hopkins (Coleoptera: Scolytidae).Journal of Chemical Ecology 22: 1861-1875 Green leaf volatiles as antiaggregants for the mountain pine beetle, Dendroctonus ponderosae Hopkins (Coleoptera: Scolytidae)
mountain pine beetle; Dendroctonus ponderosae; Coleoptera; Scolytidae; antiaggregant; verbenone; green leaf volatiles; 1-hexanol; (E)-2-hexen-1-ol; (E)-3-hexen-1-ol; (Z)-2-hexen-1-ol; (Z)-3-hexen-1-ol
We tested the hypothesis that green leaf volatiles act as antiaggregants for the mountain pine beetle (MPB), Dendroctonus ponderosae Hopkins. In coupled gas chromatographic-electroantennographic detection (GC-EAD) analysis MPB antennae responded to 30 ng doses of all six-carbon green leaf alcohols tested [1-hexanol, (E)-2-hexen-1-ol, (Z)-2-hexen-1-ol, (E)-3-hexen-1-ol, and (Z)-3-hexen-1-ol], but not to the aldehydes, hexanal or (E)-2-hexenal, or to alcohol or aldehyde homologues with more or fewer than six carbon atoms. In field trapping experiments a blend of green leaf alcohols [1-hexanol, (Z)-2-hexen-1-ol, (E)-3-hexen-1-ol and (Z)-3-hexen-1-ol] effectively disrupted the response to attractive semiochemicals; a blend of the aldehydes hexanal and (E)-2-hexenal was inactive. The two best disruptants, (E)-2-hexen-1-ol and (Z)-3-hexen-1-ol, reduced catches of both sexes to levels not significantly different from catches in unbaited control traps. They also reduced the attack on trees baited with attractive MBP pheromones to a level not significantly different from that on unbaited control trees. Neither of the clerid predators captured, Enoclerus sphegeus (F.) nor Thanasimus undatulus (Say), was repelled by green leaf volatiles. Our results suggest that green leaf alcohols are promising disruptants which may be used to supplement the antiaggregation pheromone, verbenone, in protecting single high-value trees as well as carefully selected stands with low-level populations of MPBs.
