Showing papers by "Jocelyn G. Millar published in 2010"
TL;DR: Treating panel traps with Fluon greatly improves their efficiency in capturing cerambycid beetles, which will be particularly important when traps are deployed to detect very low-density populations, such as incursions of exotic species, or remnant communities of rare and endangered species.
Abstract: The most effective traps for capturing cerambycids and other saproxylic beetles are intercept designs such as funnel traps and cross-vane panel traps. We have observed that adult cerambycids of many species often alight and walk upon panel traps, and few are actually captured. In an effort to improve trap capture and retention, researchers have treated intercept traps with Rain-X, a polysiloxane formulation that renders surfaces more slippery. Here, we summarize experiments that compared the efficacies of Rain-X and Fluon, a PTFE fluoropolymer dispersion, assurface treatments for panel traps that are deployed to capture cerambycid beetles, using untreated traps as controls. Fluon-treated traps captured on average > 14x the total number of beetles, and many more cerambycid species, than were captured by Rain-X-treated or control traps. Beetles captured by Fluon-treated traps ranged in body length by 350%. They could not walk on vertical panels treated with Fluon but easily walked on those treated with Rain-X and on untreated traps. Moreover, a single Fluon treatment remained effective for the entire field season, even in inclement weather. We conclude that treating panel traps with Fluon greatly improves their efficiency in capturing cerambycid beetles. This increased efficacy will be particularly important when traps are deployed to detect very low-density populations, such as incursions of exotic species, or remnant communities of rare and endangered species. The influence of Fluon on trap efficiency may vary with product formulation and its source and also with climatic conditions.
128 citations
TL;DR: This work explored the chemically-mediated mating behavior of Mallodon dasystomus, the hardwood stump borer, and tested the hypothesis that males recognize females by a contact pheromone, finding further evidence of the critical role of contact phersomones in mating systems of longhorned beetles.
Abstract: Little is known of the reproductive behavior of longhorned beetles (Coleoptera: Cerambycidae) in the subfamily Prioninae Mallodon dasystomus (Say), the hardwood stump borer, is a widely distributed prionine that is native to the southern US Here, we explored the chemically-mediated mating behavior of M dasystomus, and tested the hypothesis that males recognize females by a contact pheromone In mating bioassays, all males tested attempted to mate with females only after contacting females with their antennae Moreover, all males attempted to mate with solvent-washed dead females treated with as little as 015 ± 003 female equivalents of conspecific cuticular extracts, confirming that compounds on the cuticle of females are essential for mate recognition Cuticular hydrocarbon profiles of females contained 13 compounds that were not present in profiles of males Among the female-specific compounds, two co-dominant methyl-branched alkanes, 2-methylhexacosane (2Me-C26) and 2-methyloctacosane (2Me-C28), accounted for 17% of the total hydrocarbons Our strategy for identifying the contact pheromone was to synthesize and test the bioactivity of female specific compounds, starting with the most abundant In bioassays, males displayed mating behavior in response to synthetic 2Me-C26 and 2Me-C28 when tested individually Furthermore, when these compounds were tested in combination, they elicited the full progression of mating behaviors, suggesting that 2Me-C26 and 2Me-C28 make up the contact pheromone These findings are further evidence of the critical role of contact pheromones in mating systems of longhorned beetles
44 citations
TL;DR: In preliminary field trials, lures loaded with this compound attracted male moths from populations of this species at a number of widely separated field sites in France, Switzerland, and Spain, clearly demonstrating the utility of pheromones in sampling potentially endangered insect species.
Abstract: Sex attractant pheromones are highly sensitive and selective tools for detecting and monitoring populations of insects, yet there has been only one reported case of pheromones being used to monitor protected species. Here, we report the identification and synthesis of the sex pheromone of a protected European moth species, Graellsia isabellae (Lepidoptera: Saturniidae), as the single component, (4E,6E,11Z)-hexadecatrienal. In preliminary field trials, lures loaded with this compound attracted male moths from populations of this species at a number of widely separated field sites in France, Switzerland, and Spain, clearly demonstrating the utility of pheromones in sampling potentially endangered insect species.
35 citations
TL;DR: A four-component sex pheromone blend that is as attractive or more attractive to male navel orangeworm moths, Amyelois transitella (Walker) (Lepidoptera: Pyralidae), is identified and may indicate a paradigm shift in the range of compounds that constitute sex phersomone blends for individual lepidopteran species.
Abstract: We identified a four-component sex pheromone blend that is as attractive or more attractive to male navel orangeworm moths, Amyelois transitella (Walker) (Lepidoptera: Pyralidae), than either unmated females or hexane extracts of pheromone glands of females. The blend consisted of (11Z,13Z)-hexadecadienal; (11Z,13Z)-hexadecadien-1-ol; (11Z,13E)-hexadecadien-1-ol; and a hydrocarbon, (3Z,6Z,9Z,12Z,15Z)-tricosapentaene (C23 pentaene), in ratios of approximately 100:100:5:5. Other minor components of pheromone gland extracts included (11Z,13E)-hexadecadienal; (11E,13Z)-hexadecadienal; (11Z,13Z)-hexadecadien-1-yl acetate; (Z)-11-hexadecenal; hexadecanal; hexadecan-1-ol; and a second pentaene, (3Z,6Z,9Z,12Z,15Z)-pentacosapentaene (C25 pentaene). These minor components did not increase attraction of male navel orangeworm to the basic four-component blend. The use of another, cross-attracted pyralid moth, Pyralisfarinalis L., as a model species was crucial in implicating the C23 pentaene as an important component of the navel orangeworm pheromone blend. The four-component navel orangeworm pheromone blend was optimized using a combination of wind tunnel and field bioassays. Attractiveness of field deployed synthetic pheromone lures decreased rapidly despite incorporation of stabilizers and use of different release devices, suggesting that degradation products antagonize male navel orangeworm responses. Overall, the combination of type I lepidopteran pheromone components consisting of C16 aldehydes and alcohols with type II components consisting of long-chain polyunsaturated hydrocarbons has now been documented in several lepidopteran species and may indicate a paradigm shift in the range of compounds that constitute sex pheromone blends for individual lepidopteran species. This suggests that careful reexamination of pheromone gland contents for both type I and type II compounds may prove fruitful in species that have been studied but for which full attractant blends have eluded identification.
34 citations
TL;DR: The rapid accumulation of introduced herbivores on an ornamental plant system in a single state is a cautionary example of what could happen if a major food or fiber crop were intentionally targeted.
Abstract: Eucalyptus spp., native to Australia, have been introduced into many parts of the world as important timber and ornamental trees. Although the trees have important silvicultural qualities, they also have generated intense dissatisfaction, particularly among groups of individuals in California. The trees have benefited from the lack of insect pests and diseases in their adventive ranges but that has changed over the past four decades. In California, two species of insect herbivores were introduced between the time trees were first introduced to the state in the middle of the 19th century and 1983. Between 1983 and 2008, an additional 16 Australian insect pests of eucalyptus have become established in the state. The modes or routes of introduction have never been established. However, examinations of different temporal and spatial patterns suggest that the introductions were nonrandom processes. It is possible that they occurred because of increased trade or movement of people, but the hypothesis that there were intentional introductions also must be considered. The rapid accumulation of introduced herbivores on an ornamental plant system in a single state is a cautionary example of what could happen if a major food or fiber crop were intentionally targeted.
32 citations
TL;DR: Deuterium label was incorporated into the C23 and C25 pentaenes after injection of (9Z,12Z,15Z)- [17,17,18, 18,18-D5]-9,12,15-octadecatrienoic acid into 1–2 d old female pupae, and support different pathways leading to the two pheromone components.
Abstract: The sex pheromone of the navel orangeworm, Amyelois transitella (Walker) (Lepidoptera: Pyralidae), consists of two different types of components, one type including (11Z,13Z)-11,13-hexadecadienal (11Z,13Z-16:Ald) with a terminal functional group containing oxygen, similar to the majority of moth pheromones reported, and another type including the unusual long-chain pentaenes, (3Z,6Z,9Z,12Z,15Z)-3,6,9,12,15-tricosapentaene (3Z,6Z,9Z,12Z,15Z-23:H) and (3Z,6Z,9Z,12Z,15Z)- 3,6,9,12,15-pentacosapentaene (3Z,6Z,9Z,12Z,15Z-25:H). After decapitation of females, the titer of 11Z,13Z-16:Ald in the pheromone gland decreased significantly, whereas the titer of the pentaenes remained unchanged. Injection of a pheromone biosynthesis activating peptide (PBAN) into the abdomens of decapitated females restored the titer of 11Z,13Z-16:Ald and even increased it above that in intact females, whereas the titer of the pentaenes in the pheromone gland was not affected by PBAN injection. In addition to common fatty acids, two likely precursors of 11Z,13Z-16:Ald, i.e., (Z)-11-hexadecenoic and (11Z,13Z)-11,13-hexadecadienoic acid, as well as traces of (Z)-6-hexadecenoic acid, were found in gland extracts. In addition, pheromone gland lipids contained (5Z,8Z,11Z,14Z,17Z)-5,8,11,14,17-icosapentaenoic acid, which also was found in extracts of the rest of the abdomen. Deuterium-labeled fatty acids, (16,16,16-D3)-hexadecanoic acid and (Z)-[13,13,14,14,15,15,16,16,16-D9]-11-hexadecenoic acid, were incorporated into 11Z,13Z-16:Ald after topical application to the sex pheromone gland coupled with abdominal injection of PBAN. Deuterium label was incorporated into the C23 and C25 pentaenes after injection of (9Z,12Z,15Z)- [17,17,18,18,18-D5]-9,12,15-octadecatrienoic acid into 1–2 d old female pupae. These labeling results, in conjunction with the composition of fatty acid intermediates found in pheromone gland extracts, support different pathways leading to the two pheromone components. 11Z,13Z-16:Ald is probably produced in the pheromone gland by Δ11 desaturation of palmitic acid to 11Z-16:Acid followed by a second desaturation to form 11Z,13Z-16:Acid and subsequent reduction and oxidation. The production of 3Z,6Z,9Z,12Z,15Z-23:H and 3Z,6Z,9Z,12Z,15Z-25:H may take place outside the pheromone gland, and appears to start from linolenic acid, which is elongated and desaturated to form (5Z,8Z,11Z,14Z,17Z)-5,8,11,14,17-icosapentaenoic acid, followed by two or three further elongation steps and finally reductive decarboxylation.
26 citations
TL;DR: In wind-tunnel assays, males did not seem to distinguish among a wide range of ratios of any of the three components added to (11Z,13Z)-hexadecadienal, which produced the highest levels of rapid source location and source contact.
Abstract: The attractiveness to male navel orangeworm moth, Amyelois transitella, of various combinations of a four-component pheromone blend was measured in wind-tunnel bioassays. Upwind flight along the pheromone plume and landing on the odor source required the simultaneous presence of two components, (11Z,13Z)-hexadecadienal and (3Z,6Z,9Z,12Z,15Z)-tricosapentaene, and the addition of either (11Z,13Z)-hexadecadien-1-ol or (11Z,13E)-hexadecadien-1-ol. A mixture of all four components produced the highest levels of rapid source location and source contact. In wind-tunnel assays, males did not seem to distinguish among a wide range of ratios of any of the three components added to (11Z,13Z)-hexadecadienal. Dosages of 10 and 100 ng of the 4-component blend produced higher levels of source location than dosages of 1 and 1,000 ng.
24 citations
TL;DR: The racemic form of the female-produced pheromone of the grape mealybug was highly attractive to male mealybugs, and in one of two field bioassays, the racemic material was significantly more attractive than the pure (R,R)-enantiomer, suggesting that the (S,S)- enantiomer might act synergistically.
Abstract: A concise synthesis of the racemic form of the female-produced pheromone of the grape mealybug was developed. The synthesis was readily adapted to production of both enantiomers of the pheromone via lipase-catalyzed kinetic resolution of an intermediate in the synthesis. Replicated field trials revealed that, contrary to a preliminary report, the (R,R)- rather than the (S,S)-enantiomer is the attractive stereoisomer. Lithium aluminum hydride reduction of the insect-produced compound to α-necrodol followed by analysis on a chiral stationary phase GC column showed that the insect-produced material was actually an 85:15 mixture of the (R,R)- and (S,S)-enantiomers. The racemic form of the pheromone was highly attractive to male mealybugs, and in one of two field bioassays, the racemic material was significantly more attractive than the pure (R,R)-enantiomer, suggesting that the (S,S)-enantiomer might act synergistically.
20 citations
TL;DR: The field results with pentaene and the unresolved complexity of the taxonomy, ecology, and management of southern coneworms support the need for a comprehensive examination of the chemical ecology of Dioryctria spp.
Abstract: In 2006-2008, we tested (3Z,6Z,9Z,12Z,15Z)-pentacosapentaene (pentaene) with the pheromone components (Z)-11-hexadecenyl acetate (Z11-16:Ac) and (Z)-9-tetradecenyl acetate (Z9-14:Ac), as sex attractants for four sympatric species of coneworms, Dioryctria Zeller (Lepidoptera: Pyralidae) in slash (Pinus elliottii Engelm.) and loblolly pine (Pinus taeda L.) seed orchards in Georgia and Louisiana, respectively. The addition ofpentaene increased catches of male southern pine coneworm, Dioryctria amatella (Hulst), in wing traps baited with Z11-16:Ac, whereas catches of Dioryctria disclusa Heinrich in traps baited with Z9-14:Ac were unaffected by the addition of pentaene. The effect of pentaene on male Dioryctria merkeli Mutuura & Munroe was inconsistent. In 2006, pentaene seemed to inhibit attraction of D. merkeli to traps baited with Z9-14:Ac, whereas in a subsequent trial in 2008, moths were equally attracted to Z9-14:Ac with or without the pentaene. We caught too few Dioryctria clarioralis (Walker) in any experiment for meaningful analyses. Our field results with pentaene and the unresolved complexity of the taxonomy, ecology, and management of southern coneworms support the need for a comprehensive examination of the chemical ecology of Dioryctria spp.
12 citations
TL;DR: In field trials, adult Chlorochroa uhleri (Stål) of both sexes were caught in significant numbers in cylindrical screen traps baited with gray rubber septum lures loaded with the main component of the male-produced pheromone, methyl (E)-6-2,3-dihydrofarnesoate.
Abstract: In field trials, adult Chlorochroa uhleri (Stal) (Heteroptera: Pentatomidae) of both sexes were caught in significant numbers in cylindrical screen traps baited with gray rubber septum lures loaded with the main component of the male-produced pheromone, methyl (E)-6-2,3-dihydrofarnesoate. Addition of the two possible minor components of the pheromone, methyl (E)-5-2,6,10-trimethyl-5,9-undecadienoate and methyl (2E,6E) -farnesoate, did not affect attraction. Combining the pheromone with different concentrations of volatiles mimicking the odors of a known host plant, alfalfa (Medicago sativa L.), had no significant effect on attraction of adult bugs, whereas combining the pheromone with the pheromones of two sympatric stink bug species, Chlorochroa sayi (Stal) and Euschistus conspersus Uhler, decreased trap captures, suggesting interference between the pheromones. Small numbers of Chlorochroa ligata (Say) adults also were attracted, but numbers caught were too low to allow statistical comparisons between lure blends. In field trials with C. sayi, all three of the male-specific pheromone compounds [methyl geranate, methyl citronellate, and methyl (E) -6-2,3-dihydrofarnesoate] were required for optimal attraction. As with C. uhleri, adults of both sexes were attracted to pheromone lures in approximately equal numbers. Because of the decreased volatility (=release rate) of methyl (E)-6-2,3-dihydrofarnesoate in comparison with the other two, lower molecular weight pheromone components, lures needed to be loaded with a disproportionately high amount of methyl (E)-6-2,3-dihydrofarnesoate to obtain the best trap catch. There was no indication that the pheromone components of C. uhleri or E. conspersus interfered with the attractiveness of the C. sayi pheromone in lures containing a blend of all three pheromones.
11 citations
TL;DR: The sex pheromone of the avocado seed moth Stenoma catenifer was constructed by coupling a vinyl iodide precursor with commercially available 1-buten-3-yne with Pd catalysis as mentioned in this paper.
TL;DR: Analytical and field trapping data suggested that a synergistic blend will be useful as an efficient monitoring tool, and possible control tool, to combat this economically and ecologically important forest defoliator.
Abstract: The grey-spotted tussock moth, Orgyia ericae Germar (Lepidoptera: Lymantriidae), is an important pest of deciduous trees and woody scrublands in northern China. In a field trapping experiment conducted during the flight of the first generation of 2009, synthetic (Z)-6-heneicosen-11-one, a common Orgyia spp. sex pheromone component, attracted O. ericae males. Gas chromatography-mass spectrometry analyses (full scan or selected ion-monitoring mode) of pheromone gland extracts from females revealed the presence of a major, a minor, and a trace component, i.e., (6Z,9Z)-heneicosa-6,9-diene, (6Z,9Z)-tricosa-6,9-diene, and (Z)-6-heneicosen-11-one, respectively. Field experiments during the flight of the second generation showed that (6Z,9Z)-tricosa-6,9-diene, the minor component, was inactive alone or in any combination with the other two components, whereas (6Z,9Z)-heneicosa-6,9-diene and (Z)-6-heneicosen-11-one were weakly attractive when tested individually. However, traps baited with a binary blend of (6Z,9Z)-heneicosa-6,9-diene and (Z)-6-heneicosen-11-one caught seven-fold more moths than any other treatment (except the ternary blend), indicating a strong synergistic interaction between the two components. The analytical and field trapping data suggested that (6Z,9Z)-heneicosa-6,9-diene and (Z)-6-heneicosen-11-one are likely the key sex pheromone components of female O. ericae. This synergistic blend will be useful as an efficient monitoring tool, and possible control tool, to combat this economically and ecologically important forest defoliator.
TL;DR: A male-specific blend of volatiles, including several sesquiterpene hydrocarbons and the highly conjugated ester methyl (2 E,4 Z,6 Z )-deca-2,4,6-trienoate 1, was synthesized and found to rearrange under GC conditions via a 1,7 sigmatropic rearrangement.
Abstract: Sexually mature male stink bugs, Thyanta pallidovirens , release a male-specific blend of volatiles, including several sesquiterpene hydrocarbons, and the highly conjugated ester methyl (2 E ,4 Z ,6 Z )-deca-2,4,6-trienoate 1 . The latter compound was synthesized, and found to rearrange under GC conditions via a 1,7 sigmatropic rearrangement. © 1997 Elsevier Science Ltd.