Using Generic Pheromone Lures to Expedite Identification of Aggregation Pheromones for the Cerambycid Beetles Xylotrechus nauticus, Phymatodes lecontei, and Neoclytus modestus modestus

Comparison of Three Attractants for the Effective Capture of Xylotrechus chinensis Adults in Multi-Funnel Traps

The Asian coleopteran Xylotrechus chinensis (Chevrolat) (Cerambycidae: Cerambycinae) is an invasive species in several European countries, attacking mulberry trees. In the current research, we evaluated the performance of three mixtures consisting of pheromones and attractants for the monitoring of X. chinensis adults. Attractant 1 (i.e., geranyl acetone, fuscumol acetate, fuscumol, monochamol, 3-hydroxyhexan-2-one, 2-methyl-1-butanol, anti-2,3-hexanediol, prionic acid + ethanol), attractant 2 (i.e., geranyl acetone, fuscumol acetate, fuscumol, monochamol, 3-hydroxyhexan-2-one, 2-methyl-1-butanol, anti-2,3-hexanediol, prionic acid + α-pinene + ethanol) and attractant 3 (i.e., geranyl acetone, fuscumol acetate, fuscumol, monochamol, 3-hydroxyhexan-2-one, 2-methyl-1-butanol, anti-2,3-hexanediol, prionic acid + α-pinene + ipsenol + ethanol) were baited in multi-funnel traps and installed in mulberries for a two-year period in Athens (Greece). The flight activity of X. chinensis starts at the end of April and terminates at the end of October. The peaks of X. chinensis flight activity were observed on 16 August 2021 and on 6 July 2022. Attractant 3 proved to be the most effective blend, catching 953 adults, followed by attractant 2 (523 adults) and attractant 1 (169 adults), throughout the experimental period. It seems that the pest was not attracted to the basic part of the blend (i.e., pheromones + ethanol). The incorporation of α-pinene and ipsenol resulted in the elevated activity of the base lure. The elevated performance of attractant 3 may be attributed to only the α-pinene and the ipsenol, or possibly the α-pinene, ipsenol, and ethanol, because the pheromone blend did not contain any of the pheromone components of the target species. Overall, attractant 3 could be a useful tool to detect and track X. chinensis in new invasive areas, triggering early management strategies against further establishment of this species.

Generic Pheromones Identified from Northern Hemisphere Cerambycidae (Coleoptera) Are Attractive to Native Longhorn Beetles from Central-Southern Chile

We conducted field bioassays with several known cerambycid pheromones in two zones of central-southern Chile: (1) Las Trancas (Ñuble region) and Coñaripe (Los Rios region) (Study 1) and (2) Rucamanque and Maquehue (La Araucania region) (Study 2). Up to eight compounds were tested individually, including 3-hydroxy-2-hexanone, (2R*,3S*)- and (2R*,3R*)-2,3-hexanediol, fuscumol, fuscumol acetate, monochamol, 2-methylbutanol, and geranylacetone. Compounds were loaded in plastic sachets placed in either multiple funnel or cross-vane panel traps hung in trees in a randomized block design (n = 3 or 4). The number of treatments and bioassay periods varied depending on the study. A total of 578 specimens belonging to 11 native species were collected, with the three captured in the highest numbers being Eryphus laetus (292 specimens), Calydon submetallicum (n = 234), and Chenoderus testaceus (n = 20). The three species are of economic importance: E. laetus is considered a minor pest in apple orchards, and the other two species infest Nothophagus hosts, including some timber species. Traps baited with 3-hydroxy-2-hexanone collected significant numbers of both sexes of the two most abundant species, and this compound was the only treatment that attracted C. submetallicum. (2R*,3R*)- and (2R*,3S*)-2,3-Hexanediols were also significantly attractive to E. laetus. Our results suggested that 3-hydroxy-2-hexanone and 2,3-hexanediols, which are known pheromone components of cerambycid species worldwide, are also likely to be conserved aggregation pheromone components among some species in western South America.

Response of native and exotic longhorn beetles to common pheromone components provides partial support for the pheromone-free space hypothesis

Longhorn beetles are among the most important groups of invasive forest insects worldwide. In parallel, they represent one of the most well-studied insect groups in terms of chemical ecology. Longhorn beetle aggregation-sex pheromones are commonly used as trap lures for specific and generic surveillance programs at points of entry and may play a key role in determining the success or failure of exotic species establishment. An exotic species might be more likely to establish in a novel habitat if it relies on a pheromone channel that is different to that of native species active at the same time of year and day, allowing for unhindered mate location (i.e., pheromone-free space hypothesis). In this study, we first tested the attractiveness of single pheromone components (i.e., racemic 3-hydroxyhexan-2-one, racemic 3-hydroxyoctan-2-one, and syn-2,3-hexanediol), and their binary and tertiary combinations, to native and exotic longhorn beetle species in Canada and Italy. Second, we exploited trap catches to determine their seasonal flight activity. Third, we used pheromone-baited "timer traps" to determine longhorn beetle daily flight activity. The response to single pheromones and their combinations was mostly species specific but the combination of more than one pheromone component allowed catch of multiple species simultaneously in Italy. The response of the exotic species to pheromone components, coupled with results on seasonal and daily flight activity, provided partial support for the pheromone-free space hypothesis. This study aids in the understanding of longhorn beetle chemical ecology and confirms that pheromones can play a key role in longhorn beetle invasions.

Species Diversity and Assemblages of Cerambycidae in the Aftermath of the Emerald Ash Borer (Coleoptera: Buptrestidae) Invasion in Riparian Forests of Southern Michigan

Extensive ash (Fraxinus spp.) mortality has been reported across much of the area in eastern North America invaded by emerald ash borer (Agrilus planipennis Fairmaire), but indirect effects of emerald ash borer invasion on native forest insects are not well-studied. We assessed cerambycid beetle (Coleoptera: Cerambycidae) species captured in baited cross-vane panel traps during the 2017 and 2018 growing seasons. Traps were placed in 12 riparian forest sites distributed across three watersheds selected to represent the temporal gradient of the emerald ash borer invasion from southeastern to southwestern Michigan. Although ash species originally dominated overstory vegetation in all sites, >85% of ash basal area has been killed by emerald ash borer. We captured a total of 3,645 beetles representing 65 species and five subfamilies. Species assemblages in southeast sites, with the longest history of emerald ash borer invasion, differed from those in south central and southwest Michigan, which were similar. These differences were largely due to three species, which accounted for >60% of beetle captures in southeast Michigan. Associations among site-related variables and beetle captures indicated cerambycid species assemblages were associated most strongly with abundance and decay stage of coarse woody debris. During both years, >90% of cerambycid species were captured by mid-summer but seasonal activity differed among and within tribes. Numbers of beetles captured by canopy and ground traps were similar but species richness was higher in canopy traps than ground traps. Results suggest inputs of emerald ash borer-killed ash can have temporally lagged, secondary effects on cerambycid communities.

The Role of Minor Pheromone Components in Segregating 14 Species of Longhorned Beetles (Coleoptera: Cerambycidae) of the Subfamily Cerambycinae

We present research on the chemical ecology of 14 species of longhorned beetles (Coleoptera: Cerambycidae), in four tribes of the subfamily Cerambycinae, conducted in east-central Illinois over 8 yr. Adult males produce aggregation-sex pheromones that attract both sexes. Twenty independent field bioassays explored the pheromone chemistry of the species and tested the possible attractive or antagonistic effects of compounds that are not produced by a given species, but are pheromone components of other species. Analyses of beetle-produced volatiles revealed compounds that had not been reported previously from several of the species. The most common pheromone component was (R)-3-hydroxyhexan-2-one, but pheromones of some species included isomers of the related 2,3-hexanediols. Males of the congeners Phymatodes amoenus (Say) and Phymatodes testaceus (L.) produced pure (R)-2-methylbutan-1-ol. Enantiomers of 2-methylbutan-1-ol also proved to be powerful synergists for Megacyllene caryae (Gahan), Sarosesthes fulminans (F.), and Xylotrechus colonus (F.). The major components of pheromone blends were consistently present in collections of headspace volatiles from male beetles, and only the major components were inherently attractive to a subset of species when tested as single components. Minor components of some species acted as powerful synergists, but in other cases appeared not to influence attraction. Among the minor components identified in headspace extracts from males, 2,3-hexanedione and 2-hydroxyhexan-3-one appeared to be analytical artifacts or biosynthetic by-products, and were neither attractants nor synergists. The antagonistic effects of minor compounds produced by heterospecific males suggest that these compounds serve to maintain prezygotic reproductive isolation among some species that share pheromone components.

Common Cerambycid Pheromone Components as Attractants for Longhorn Beetles (Cerambycidae) Breeding in Ephemeral Oak Substrates in Northern Europe

Longhorn beetles are ecologically important insects in forest ecosystems as decomposers of woody substrates, microhabitat engineers, and as components of forest food webs. These species can be greatly affected both positively and negatively by modern forestry management practices, and should be monitored accordingly. Through headspace sampling, coupled gas chromatography-electroantennography, gas chromatography-mass spectrometry, and field bioassays, we identified two compounds, 2-methyl-1-butanol and 3-hydroxy-2-hexanone, that constitute aggregation-sex pheromone attractants of three cerambycid species which breed primarily in different types of fresh, recently dead oak wood in Northern Europe: Pyrrhidium sanguineum (L.), Phymatodes alni ssp. alni (L.), and Phymatodes testaceus (L.) (Cerambycinae: Callidiini). Analyses of headspace volatiles collected from live insects indicated that the male-produced aggregation-sex pheromone of P. sanguineum is a 1–15:100 blend of (R)-2-methyl-1-butanol and (R)-3-hydroxy-2-hexanone, whereas the corresponding ratios for P. alni were 70–110:100. In field bioassays, adult P. sanguineum and P. alni were significantly attracted to multiple blends with varying ratios of the two compounds. When tested individually, the compounds were minimally attractive. In contrast, adult P. testaceus exhibited nonspecific attraction to both of the individual compounds and to different blends, despite the hydroxyketone not being part of its pheromone, which consists of (R)-2-methyl-1-butanol alone. Overall, our results suggest that a blend of 50:100 of racemic 2-methyl-1-butanol and 3-hydroxy-2-hexanone is appropriate for parallel, cost-efficient pheromone-based monitoring of all three species. In particular, these species could serve as useful indicators of how modern forestry practices affect a whole guild of saproxylic insects that require ephemeral deadwood substrates for successful breeding.

Chemical Ecology of Capnodis tenebrionis (L.) (Coleoptera: Buprestidae): Behavioral and Biochemical Strategies for Intraspecific and Host Interactions

This study focuses on several aspects of communication strategies adopted by adults of the Mediterranean flat-headed root-borer Capnodis tenebrionis (Coleoptera: Buprestidae). Morphological studies on the structures involved in mate recognition and acceptance revealed the presence of porous areas in the pronota in both sexes. These areas were variable in shape and size, but proportionally larger in males. The presence of chaetic, basiconic, and coeloconic sensilla in the antennae of both males and females was verified. Bioassays revealed stereotyped rituals in males and the involvement of female pronotal secretions in mate recognition and acceptance. During the mating assays, the female’s pronotum was covered by a biologically inert polymeric resin (DenFil^TM), which prevented males from detecting the secretions and from completing the copulation ritual. The use of the resin allowed for the collection of chemical compounds. GC-MS analysis of the resin suggested it may be used to retain compounds from insect body surfaces and revealed sex-specific chemical profiles in the cuticles. Since adult C. tenebrionis may use volatile organic compounds (VOCs) emitted from leaves or shoots, the VOC emission profiles of apricot trees were characterized. Several volatiles related to plant-insect interactions involving fruit tree species of the Rosaceae family and buprestid beetles were identified. To improve understanding of how VOCs are perceived, candidate soluble olfactory proteins involved in chemoreception (odorant-binding proteins and chemosensory proteins) were identified using tissue and sex-specific RNA-seq data. The implications for chemical identification, physiological and ecological functions in intraspecific communication and insect–host interactions are discussed and potential applications for monitoring presented.

Isolation and identification of a male-produced aggregation-sex pheromone for the velvet longhorned beetle, Trichoferus campestris

The velvet longhorned beetle, Trichoferus campestris (Faldermann) (“VLB”; Coleoptera: Cerambycidae), is native to eastern Asia where it infests and damages a wide range of deciduous and coniferous tree species, including orchard and timber species. Immature stages of VLB are transported to new countries via international commerce, and populations have established outside the native range of the species. Here, we show that identification of pheromones of invasive pest species can be expedited by knowledge of the semiochemistry of related taxa. Histological sectioning revealed subcuticular, male-specific prothoracic glands connected to pits in the cuticle, which, in related species, are diagnostic for production of male-produced aggregation-sex pheromones, usually characterized by 2,3-alkanediol/hydroxyketone structural motifs. However, in preliminary field bioassays, beetles were not attracted by any known cerambycid pheromones. Subsequently, we identified a novel variant of the hydroxyketone motif (“trichoferone”) from headspace volatiles of males. In field bioassays, synthetic trichoferone was more attractive to both sexes of VLB than previously developed high-release-rate ethanol lures, and attraction was strongly female biased. This study demonstrated the utility of the prothoracic gland trait for predicting pheromone use in cerambycid species in the subfamily Cerambycinae, and that identification of pheromones of novel species can be expedited by knowledge of pheromones of related species. Trichoferone should prove to be a valuable tool for detection of VLB in regions where the beetle is or may become established.

Identification of the Aggregation-sex Pheromone of the Cerambycid Beetle Phymatodes pusillus ssp. pusillus and Evidence of a Synergistic Effect from a Heterospecific Pheromone Component

The longhorn beetle Phymatodes (Poecilium) pusillus ssp. pusillus is a rare, elusive species that is included on Red Lists of threatened species. Previously, 1-hexanol and 1-butanol were reported as putative components of the aggregation-sex pheromone of this species, but behavioral assays to confirm this have not been performed. In this study, we undertook a comprehensive examination of P. p. pusillus to verify the presence of a pheromone. Adult beetles were reared from colonized wood and used for headspace sampling. Analyses by gas chromatography-mass spectrometry revealed that two compounds were present in large quantities in the extracts of males, but absent in extracts from females. Male and female antennae showed repeatable responses to the two compounds in electrophysiological recordings. Using synthetic standards, we were able to identify the compounds as 1-hexanol and 2-methyl-1-butanol. A field bioassay demonstrated that the two compounds were unattractive when applied singly, but elicited significant attraction of female and male beetles when applied in blends of different ratios. We also found that the species exhibited significant attraction to a blend of 3-hydroxy-2-hexanone and 2-methyl-1-butanol, which is the aggregation-sex pheromone of at least two closely related and sympatric species. The presence of the heterospecific component 3-hydroxy-2-hexanone synergized a response to 2-methyl-1-butanol. The pheromone of these species may function as a host cue for P. p. pusillus as the three species have similar phenology and substrate demands. The aggregation-sex pheromone of P. p. pusillus can be used for population monitoring and as a tool to study the general ecology and conservation requirements of this rare species.

Identifying Possible Pheromones of Cerambycid Beetles by Field Testing Known Pheromone Components in Four Widely Separated Regions of the United States

The pheromone components of many cerambycid beetles appear to be broadly shared among related species, including species native to different regions of the world. This apparent conservation of pheromone structures within the family suggests that field trials of common pheromone components could be used as a means of attracting multiple species, which then could be targeted for full identification of their pheromones. Here, we describe the results of such field trials that were conducted in nine states in the northeastern, midwestern, southern, and western United States. Traps captured 12,742 cerambycid beetles of 153 species and subspecies. Species attracted in significant numbers to a particular treatment (some in multiple regions) included 19 species in the subfamily Cerambycinae, 15 species in the Lamiinae, one species in the Prioninae, and two species in the Spondylidinae. Pheromones or likely pheromones for many of these species, such as 3-hydroxyhexan-2-one and syn- and anti-2,3-hexanediols for cerambycine species, and fuscumol and/or fuscumol acetate for lamiine species, had already been identified. New information about attractants (in most cases likely pheromone components) was found for five cerambycine species (Ancylocera bicolor [Olivier], Elaphidion mucronatum [Say], Knulliana cincta cincta [Drury], Phymatodes aeneus LeConte, and Rusticoclytus annosus emotus [Brown]), and five lamiine species (Ecyrus dasycerus dasycerus [Say], Lepturges symmetricus [Haldeman], Sternidius misellus [LeConte], Styloleptus biustus biustus [LeConte], and Urgleptes signatus [LeConte]). Consistent attraction of some species to the same compounds in independent bioassays demonstrated the utility and reliability of pheromone-based methods for sampling cerambycid populations across broad spatial scales.

Synergism between Enantiomers Creates Species-Specific Pheromone Blends and Minimizes Cross-Attraction for Two Species of Cerambycid Beetles

Research over the last decade has revealed extensive parsimony among pheromones within the large insect family Cerambycidae, with males of many species producing the same, or very similar aggregation pheromones. Among some species in the subfamily Cerambycinae, interspecific attraction is minimized by temporal segregation, and/or by minor pheromone components that synergize attraction of conspecifics or inhibit attraction of heterospecifics. Less is known about pheromone-based mechanisms of reproductive isolation among species in the largest subfamily, the Lamiinae. Here, we present evidence that the pheromone systems of two sympatric lamiine species consist of synergistic blends of enantiomers of (E)-6,10-dimethyl-5,9-undecadien-2-ol (fuscumol) and the structurally related (E)-6,10-dimethyl-5,9-undecadien-2-yl acetate (fuscumol acetate), as a mechanism by which species-specific blends of pheromone components can minimize interspecific attraction. Male Astylidius parvus (LeConte) were found to produce (R)- and (S)-fuscumol + (R)-fuscumol acetate + geranylacetone, whereas males of Lepturges angulatus (LeConte) produced (R)- and (S)-fuscumol acetate + geranylacetone. Field experiments confirmed that adult beetles were attracted only by their species-specific blend of the enantiomers of fuscumol and fuscumol acetate, respectively, and not to the individual enantiomers. Because other lamiine species are known to produce single enantiomers or blends of enantiomers of fuscumol and/or fuscumol acetate, synergism between enantiomers, or inhibition by enantiomers, may be a widespread mechanism for forming species-specific pheromone blends in this subfamily.

10-Methyldodecanal, a Novel Attractant Pheromone Produced by Males of the South American Cerambycid Beetle Eburodacrys vittata

We report the identification, synthesis, and field bioassay of a novel attractant pheromone produced by males of Eburodacrys vittata (Blanchard), a South American cerambycid beetle in the subfamily Cerambycinae. Headspace volatiles from males contained a sex-specific compound, identified as 10-methyldodecanal. In a field bioassay conducted in Brazil, significant numbers of males and females were caught in traps baited with synthesized racemic 10-methyldodecanal, consistent with the aggregation-sex pheromones produced by males of many cerambycine species. This compound represents a new structural class of cerambycid pheromones, and it is the first pheromone identified for a species in the tribe Eburiini.

Sex and Aggregation-Sex Pheromones of Cerambycid Beetles: Basic Science and Practical Applications

Research since 2004 has shown that the use of volatile attractants and pheromones is widespread in the large beetle family Cerambycidae, with pheromones now identified from more than 100 species, and likely pheromones for many more. The pheromones identified to date from species in the subfamilies Cerambycinae, Spondylidinae, and Lamiinae are all male-produced aggregation-sex pheromones that attract both sexes, whereas all known examples for species in the subfamilies Prioninae and Lepturinae are female-produced sex pheromones that attract only males. Here, we summarize the chemistry of the known pheromones, and the optimal methods for their collection, analysis, and synthesis. Attraction of cerambycids to host plant volatiles, interactions between their pheromones and host plant volatiles, and the implications of pheromone chemistry for invasion biology are discussed. We also describe optimized traps, lures, and operational parameters for practical applications of the pheromones in detection, sampling, and management of cerambycids.

Optimizing Generic Cerambycid Pheromone Lures for Australian Biosecurity and Biodiversity Monitoring

The cerambycid beetles comprise a diverse family that includes many economically important pests of living and dead trees. Pheromone lures have been developed for cerambycids in many parts of the world, but to date, have not been tested in Australia. In this study, we tested the efficacy of several pheromones, identified from North American and European species, as attractants for cerambycids at three sites in southeast Queensland, Australia. Over two field seasons, we trapped 863 individuals from 47 cerambycid species. In the first season, racemic 3-hydroxyhexan-2-one was the most attractive compound among the eight pheromones tested. Subsequently, we aimed to optimize trapping success by combining this compound with other components. However, neither the addition of other pheromone components nor host plant volatiles improved the efficacy of 3-hydroxyhexan-2-one alone. We also tested a generic pheromone blend developed for North American cerambycids, and found that only the combination of this blend with host plant volatiles improved trapping success. The Australian cerambycid fauna is not well known, and effective lures for use in trapping beetles would greatly assist in the study of this important group. Effective semiochemical lures would also have implications for biosecurity through improved monitoring for invasive species.

The Influence of Host Plant Volatiles on the Attraction of Longhorn Beetles to Pheromones

Host plant volatiles have been shown to strongly synergize the attraction of some longhorn beetle species (Coleoptera: Cerambycidae) to their pheromones. This synergism is well documented among species that infest conifers, but less so for angiosperm-infesting species. To explore the extent of this phenomenon in the Cerambycidae, we first tested the responses of a cerambycid community to a generic pheromone blend in the presence or absence of chipped material from host plants as a source of host volatiles. In the second phase, blends of oak and conifer volatiles were reconstructed, and tested at low, medium, and high release rates with the pheromone blend. For conifer-infesting species in the subfamilies Spondylidinae and Lamiinae, conifer volatiles released at the high rate synergized attraction of some species to the pheromone blend. When comparing high-release rate conifer blend with high-release rate α-pinene as a single component, species responses varied, with Asemum nitidum LeConte being most attracted to pheromones plus α-pinene, whereas Neospondylis upiformis (Mannerheim) were most attracted to pheromones plus conifer blend and ethanol. For oak-infesting species in the subfamily Cerambycinae, with the exception of Phymatodes grandis Casey, which were most attracted to pheromones plus ethanol, neither synthetic oak blend nor ethanol increased attraction to pheromones. The results indicate that the responses to combinations of pheromones with host plant volatiles varied from synergistic to antagonistic, depending on beetle species. Release rates of host plant volatiles also were important, with some high release rates being antagonistic for oak-infesting species, but acting synergistically for conifer-infesting species.

Identification of a Pheromone Component and a Critical Synergist for the Invasive Beetle Callidiellum rufipenne (Coleoptera: Cerambycidae)

The invasive Asian cerambycid beetle Callidiellum rufipenne (Motschulsky), informally known as the Japanese cedar longhorned beetle, was first detected in North America in North Carolina in 1997. The beetle has since been detected in neighboring states and is expected to further expand its range. However, delineating the current distribution of C. rufipenne has been hindered by the lack of efficient sampling methods. Here, we present the results of research on the chemistry of volatile pheromones of C. rufipenne. Analyses of headspace odors revealed that males produce (R)-3-hydroxyhexan-2-one, with lesser amounts of (S)-3-hydroxyhexan-2-one, and (R)- and (S)-2-hydroxyhexan-3-one. In field bioassays conducted over several years in Connecticut, where populations of the beetle were well established, no reconstructed blend of these compounds was significantly attractive to beetles of either sex. However, during field trials in Japan that targeted another species, we discovered that adult male and female C. rufipenne were attracted to a blend of racemic 3-hydroxyhexan-2-one and a novel natural product, 1-(1H-pyrrol-2-yl)-1,2-propanedione. Attraction to (R)-3-hydroxyhexan-2-one and the pyrrole subsequently was confirmed in field trials in Connecticut. Although it is unclear why the pyrrole acts as a synergist for a species that apparently does not produce it, the serendipitous discovery that adult C. rufipenne are attracted by the blend of ketone and pyrrole provides a badly needed method for monitoring its ongoing range expansion within North America, and for detecting new introductions in other parts of the world.

2R,3S)-2,3-Octanediol, a Female-Produced Sex Pheromone of Megopis costipennis (Coleoptera: Cerambycidae: Prioninae)

During field screening trials of a number of known cerambycid pheromones in China, males of Megopis costipennis (White) (Coleoptera: Cerambycidae: Prioninae: Callipogonini) were found to be specifically attracted to racemic anti-2,3-octanediol, suggesting that one of the enantiomers of this compound might be a female-produced sex pheromone of this species. Analysis of volatiles produced by beetles of both sexes confirmed this hypothesis: females produced (2R,3S)-2,3-octanediol, whereas males did not, and in coupled gas chromatography–electroantennogram detection analyses, antennae from male beetles responded strongly to this compound. In field trials, males were equally attracted to traps baited with either (2R,3S)-2,3-octanediol or racemic anti-2,3-octanediol, indicating that the enantiomeric (2S,3R)-2,3-octanediol does not antagonize attraction to the naturally produced enantiomer. Thus, the more economical racemic anti-2,3-octanediol can be used for trap baits for this species. Homologous 2,3-hexanediols previously had been identified as sex pheromones or sex attractants of prionine species in the genus Tragosoma Audinet-Serville of the tribe Meroscelisini.

Further contributions to the longhorn beetle (Coleoptera, Cerambycidae) fauna of New Brunswick and Nova Scotia, Canada

Sixteen species of Cerambycidae are newly recorded for New Brunswick, Canada; Arhopalus obsoletus (Randall), Atimia confusa confusa (Say), Callidium frigidum Casey, Phymatodes amoenus (Say), Phymatodes testaceus (Linnaeus), Neoclytus mucronatus mucronatus (Fabricius), Xylotrechus aceris Fisher, Xylotrechus sagittatus sagittatus (Germar), Tylonotus bimaculatus Haldeman, Lepturges angulatus (LeConte), Lepturges symmetricus (Haldeman), Urgleptes querci (Fitch), Oplosia nubila (LeConte), Eupogonius subarmatus (LeConte), Monochamus carolinensis (Olivier), and Pogonocherus parvulus LeConte. Urgleptes signatus (LeConte) and Urgleptes querci are newly recorded from Nova Scotia. All but two specimens were collected in 12-funnel Lindgren traps. Xylotrechus aceris, Tylonotus bimaculatus, Lepturges angulatus, Lepturges symmetricus, Urgleptes signatus (NS), and Pogonocherus parvulus were detected exclusively in traps deployed in the forest canopy, and most individuals of Oplosia nubila and Monochamus carolinensis were captured in canopy traps. Arhopalus obsoletus, Atimia confusa confusa, Callidium frigidum, Phymatodes testaceus, and Xylotrechus sagittatus sagittatus were captured almost exclusively in traps near (1 m above) the forest floor. These results highlight the importance of sampling both the understory and upper canopy when using traps for surveying diversity of Cerambycidae.

Olfactory receptor neuron responses of a longhorned beetle, Tetropium fuscum (Fabr.) (Coleoptera: Cerambycidae), to pheromone, host, and non-host volatiles

Longhorn wood-boring beetles (Coleoptera: Cerambycidae) use olfactory cues to find mates and hosts for oviposition. Tetropium fuscum (Fabr.) is an invasive longhorned wood-boring beetle originating from Europe that has been established in Nova Scotia, Canada, since at least 1990. This study used single sensillum recordings (SSR) to determine the response of olfactory receptor neurons (ORNs) in the antennal sensilla of male and female T. fuscum to different kinds of olfactory cues, namely host volatiles, non-host volatiles, the aggregation pheromone of T. fuscum (fuscumol), and an aggregation pheromone emitted by other species of longhorn beetles (3-hydroxyhexan-2-one). Each compound had been previously shown to elicit antennal activity in T. fuscum using electroantennography or had been shown to elicit behavioral activity in T. fuscum or other cerambycids. There have been very few SSR studies done on cerambycids, and ours is the first to compare response profiles of pheromone components as well as host and non-host volatiles. Based on SSR studies with other insects, we predicted we would find ORNs that responded to the pheromone alone (pheromone-specialists), as well as ORNs that responded only to host or non-host volatiles, i.e., separation of olfactory cue perception at the ORN level. Also, because male T. fuscum emerge earlier than females and are the pheromone-emitting sex, we predicted that the number of pheromone-sensitive ORNs would be greater in females than males. We found 140 ORNs housed within 97 sensilla that responded to at least one of the 13 compounds. Fuscumol-specific ORNs made up 15% (21/140) of all recordings, but contrary to our prediction, an additional 22 ORNs (16%) responded to fuscumol plus at least one other compound; in total, fuscumol elicited a response from 43/140 (31%) of ORNs with fuscumol-specific ORNs accounting for half of these. Thus, our prediction that pheromone reception would be segregated on specialist ORNs was only partially supported. Our prediction that females would have more ORNs that responded to fuscumol than would males was also not supported, as there was no difference. The stressed-host volatile linalool elicited the most responses of any compound tested, 43% of all recordings.

Responses of Cerambycidae and Other Insects to Traps Baited With Ethanol, 2,3-Hexanediol, and 3,2-Hydroxyketone Lures in North-Central Georgia

In north-central Georgia, 13 species of woodboring beetles (Coleoptera: Cerambycidae: Cerambycinae) were attracted to multiple-funnel traps baited with ethanol and one of the following pheromones: (1) racemic 3-hydroxyhexan-2-one; (2) racemic 3-hydroxyoctan-2-one; and (3) syn-2,3-hexanediol. The following species were attracted to traps baited with ethanol and 3-hydroxyhexan-2-one: Anelaphus pumilus (Newman), Eburia quadrigeminata (Say), Euderces pini (Olivier), Knulliana cincta (Drury), Neoclytus mucronatus (F.), Neoclytus scutellaris (Olivier), and Xylotrechus colonus (F.). Clytus marginicollis Castelnau & Gory, and Anelaphus parallelus (Newman) were attracted to traps baited with ethanol and 3-hydroxyoctan-2-one, whereas traps baited with ethanol and syn-2,3-hexanediol were attractive to Anelaphus villosus (F.), A. parallelus, Neoclytus acuminatus (F.), Neoclytus jouteli jouteli Davis, and Megacyllene caryae (Gahan). Ethanol enhanced catches of seven cerambycid species in traps baited with syn-2,3-hexanediol and 3,2-hydroxyketones. Catches of bark and ambrosia beetles (Curculionidae: Scolytinae) in ethanol-baited traps were largely unaffected by the addition of syn-2,3-hexanediol and 3,2-hydroxyketone lures, except for two species. The mean catches of Hypothenemus rotundicollis Wood & Bright and Dryoxylon onoharaensum (Murayama) in ethanol-baited traps increased and decreased, respectively, with the addition of racemic 3-hydroxyoctan-2-one. Traps baited with ethanol and syn-2,3-hexanediol were attractive to Xylobiops basilaris (Say) (Bostrichidae) and Chariessa pilosa (Forster) (Cleridae), whereas Temnoscheila virescens (F.) (Trogossitidae) were attracted to traps baited with ethanol and 3-hydroxyhexan-2-one. The assassin bug, Apiomerus crassipes (F.) (Hemiptera: Reduviidae), was attracted to traps baited with ethanol and 3,2-hydroxyketones.

Chiral methyl-branched pheromones

Insect pheromones are some of the most interesting natural products because they are utilized for interspecific communication between various insects, such as beetles, moths, ants, and cockroaches. A large number of compounds of many kinds have been identified as pheromone components, reflecting the diversity of insect species. While this review deals only with chiral methyl-branched pheromones, the chemical structures of more than one hundred non-terpene compounds have been determined by applying excellent analytical techniques. Furthermore, their stereoselective syntheses have been achieved by employing trustworthy chiral sources and ingenious enantioselective reactions. The information has been reviewed here not only to make them available for new research but also to understand the characteristic chemical structures of the chiral pheromones. Since biosynthetic studies are still limited, it might be meaningful to examine whether the structures, particularly the positions and configurations of the branched methyl groups, are correlated with the taxonomy of the pheromone producers and also with the function of the pheromones in communication systems.

Structure and development of male pheromone gland of longicorn beetles and its phylogenetic relationships within the tribe Clytini

The male sex pheromone of the longicorn beetle, Xylotrechus pyrrhoderus pyrrhoderus Bates (Cerambycidae: Tribe Clytini) plays an important role in attracting females. This pheromone is produced by the pheromone gland located in the prothorax. However, the detailed structure and underlying developmental process of this gland are still unknown. We investigated the gland structure by using histological analysis and confirmed that the gland consists of the following parts: gland cell mass, a unique spherical space in the cuticle layer, and ductules connecting the gland cells with the spherical space and conducting canals to the outer opening. The gland structure first appeared male-specific in the late pupal stage, during which the epidermal cells began depositing the exocuticle; the development of the gland was completed after adult emergence. Furthermore, we verified the structural equivalents of the X. p. pyrrhoderus male pheromone gland in 11 species of 2 tribes, Clytini and Anaglyptini. The glands of these insects could be classified into four types on the basis of the absence or presence of the spherical space and the division of the gland cell mass layer. Most noteworthy, all the species with the spherical space and division-type gland were restricted to the Xylotrechus clade, as inferred from the molecular phylogenetic analysis. These results suggest that Clytini and Anaglyptini species share a fundamental process of male pheromone gland development, and that the Japanese Xylotrechus species might have established their current status by developing distinct structural features in the male pheromone gland.

North American Species of Cerambycid Beetles in the Genus Neoclytus Share a Common Hydroxyhexanone-Hexanediol Pheromone Structural Motif

Many species of cerambycid beetles in the subfamily Cerambycinae are known to use male-produced pheromones composed of one or a few components such as 3-hydroxyalkan-2-ones and the related 2,3-alkanediols. Here, we show that this pheromone structure is characteristic of the cerambycine genus Neoclytus Thomson, based on laboratory and field studies of 10 species and subspecies. Males of seven taxa produced pheromones composed of (R)-3-hydroxyhexan-2-one as a single component, and the synthetic pheromone attracted adults of both sexes in field bioassays, including the eastern North American taxa Neoclytus caprea (Say), Neoclytus mucronatus mucronatus (F.), and Neoclytus scutellaris (Olivier), and the western taxa Neoclytus conjunctus (LeConte), Neoclytus irroratus (LeConte), and Neoclytus modestus modestus Fall. Males of the eastern Neoclytus acuminatus acuminatus (F.) and the western Neoclytus tenuiscriptus Fall produced (2S,3S)-2,3-hexanediol as their dominant or sole pheromone component. Preliminary data also revealed that males of the western Neoclytus balteatus LeConte produced a blend of (R)-3-hydroxyhexan-2-one and (2S,3S)-2,3-hexanediol but also (2S,3S)-2,3-octanediol as a minor component. The fact that the hydroxyketone-hexanediol structural motif is consistent among these North American species provides further evidence of the high degree of conservation of pheromone structures among species in the subfamily Cerambycinae.

(2S,4E)-2-Hydroxy-4-octen-3-one, a Male-Produced Attractant Pheromone of the Cerambycid Beetle Tylonotus bimaculatus

We report the identification of a novel pheromone structure from males of the cerambycid beetle Tylonotus bimaculatus Haldeman (Cerambycinae: Hesperophanini), a species native to eastern North America. Volatiles collected from adult males contained (2S,4E)-2-hydroxyoct-4-en-3-one (71%), (3R,4E)-3-hydroxyoct-4-en-2-one (15%), (E)-4-octen-2,3-dione (13%), and 2,3-octanedione (1.5%). Four independent field bioassays with synthetic compounds confirmed that adults of both sexes were attracted by the racemate of the major component, (E)-2-hydroxyoct-4-en-3-one. No other cerambycid species were attracted in significant numbers. Attraction of both sexes is consistent with the male-produced pheromones of many other species in the subfamily Cerambycinae, but T. bimaculatus is unusual in having a pheromone chemistry that is so far unique among species in that subfamily.

Carbonyl reduction in the biosynthesis of a male sex pheromone secreted by the grape borer Xylotrechus pyrrhoderus

Males of the cerambycid beetle Xylotrechus pyrrhoderus release a mixture of (S)-2-hydroxy-3-octanone [(S)-1] and (2S,3S)-2,3-octanediol [(2S,3S)-2] as a sex pheromone that attracts conspecific females. The chemical structures of these pheromone components include a common motif and are assumed to be biosynthetically related. Here, we show that deuterated (S)-1, applied on the cuticle of a pronotal pheromone gland, was converted into (2S,3S)-2, that included deuterium atoms, but a reverse conversion did not take place. These results reveal a carbonyl reductase to be active in the pheromone gland, and that the ketol is a biosynthetic precursor of the diol. Males did not produce (R)-1; however, deuterated (R)-1 was converted into (2R,3R)-2, indicating an attack of the enzyme from the opposite side of the hydroxyl group at the 2-position. Furthermore, to understand the substrate specificity of the enzyme, racemates of 2-hydroxy-3-hexanone and 2-hydroxy-3-decanone were synthesized and applied to the gland. Their conversion into the corresponding diols suggests that the enzyme reduces the carbonyl group at the 3-position, regardless of the chain length.

Effects of pheromone and plant volatile release rates and ratios on trapping Anoplophora glabripennis (Coleoptera: Cerambycidae) in China

Native to China and Korea, the Asian longhorned beetle, Anoplophora glabripennis (Motschulsky) (Coleoptera: Cerambycidae), is a polyphagous wood-boring pest for which a trapping system would greatly benefit eradication and management programs in both the introduced and native ranges. Over two field seasons, a total of 160 flight intercept panel traps were deployed in Harbin, China, which trapped a total of 65 beetles. In 2012, traps using lures with a 1:1 ratio of the male-produced pheromone components (4-(n-heptyloxy)butanal and 4-(n-heptyloxy)butan-1-ol) designed to release at a rate of 1 or 4 milligram per day per component in conjunction with the plant volatiles (-)-linalool, trans-caryophyllene, and (Z)-3-hexen-1-ol caught significantly more A. glabripennis females than other pheromone release rates, other pheromone ratios, plant volatiles only, and no lure controls. Males were caught primarily in traps baited with plant volatiles only. In 2013, 10× higher release rates of these plant volatiles were tested, and linalool oxide was evaluated as a fourth plant volatile in combination with a 1:1 ratio of the male-produced pheromone components emitted at a rate of 2 milligram per day per component. Significantly more females were trapped using the pheromone with the 10-fold higher three or four plant volatile release rates compared with the plant volatiles only, low four plant volatile + pheromone, and control. Our findings show that the male-produced pheromone in combination with plant volatiles can be used to detect A. glabripennis. Results also indicate that emitters should be monitored during the field season, as release rates fluctuate with environmental conditions and can be strongly influenced by formulation additives.

Seasonal phenology of the cerambycid beetles of east-central Illinois

We summarize field data on the species composition and seasonal phenology of the community of cerambycid beetles of east-central Illinois. Data were drawn from field bioassays conducted during 2009 - 2012 that tested attraction of adult beetles of diverse species to a variety of synthetic pheromones and host plant volatiles. A total of 34,086 beetles of 114 species were captured, including 48 species in the subfamily Cerambycinae, 41 species in the Lamiinae, 19 species in the Lepturinae, two species in the Spondylidinae, and one species each in the Necydalinae, Parandrinae, Prioninae, and the Disteniidae. Most of the best-represented species were attracted to pheromones that were included in field experiments, particularly species that use (R)-3-hydroxyhexan-2-one as a pheromone component. The species captured, and their patterns of abundance and seasonal phenology were similar to those in an earlier study conducted in Pennsylvania. The most abundant species identified in both studies included the cerambycines Elaphidion mucronatum (Say), Neoclytus a. acuminatus (F.), Neoclytus m. mucronatus (F.), and Xylotrechus colonus (F.). Cerambycine species became active in an orderly progression from early spring through late fall, whereas most lamiine species were active in summer and fall, and lepturine species were limited to summer. Potential cross attraction between some cerambycine species that shared pheromone components may have been averted by differences in seasonal activity period, and by minor pheromone components that acted as synergists for conspecifics and/or antagonists for heterospecifics. These results provide quantitative data on the abundance and seasonal phenology of a large number of species.

2,3-Hexanediols as sex attractants and a female-produced sex pheromone for cerambycid beetles in the prionine genus Tragosoma

Recent work suggests that closely related cerambycid species often share pheromone components, or even produce pheromone blends of identical composition. However, little is known of the pheromones of species in the subfamily Prioninae. During field bioassays in California, males of three species in the prionine genus Tragosoma were attracted to 2,3-hexanediols, common components of male-produced aggregation pheromones of beetles in the subfamily Cerambycinae. We report here that the female-produced sex pheromone of Tragosoma depsarium "sp. nov. Laplante" is (2R,3R)-2,3-hexanediol, and provide evidence from field bioassays and electroantennography that the female-produced pheromone of both Tragosoma pilosicorne Casey and T. depsarium "harrisi" LeConte may be (2S,3R)-2,3-hexanediol. Sexual dimorphism in the sculpting of the prothorax suggests that the pheromone glands are located in the prothorax of females. This is the second sex attractant pheromone structure identified from the subfamily Prioninae, and our results provide further evidence of pheromonal parsimony within the Cerambycidae, in this case extending across both subfamily and gender lines.

Sequencing and characterizing odorant receptors of the cerambycid beetle Megacyllene caryae

Odorant receptors (Ors) are a unique family of ligand-gated ion channels and the primary mechanism by which insects detect volatile chemicals. Here, we describe 57 putative Ors sequenced from an antennal transcriptome of the cerambycid beetle Megacyllene caryae (Gahan). The male beetles produce a pheromone blend of nine compovnents, and we functionally characterized Ors tuned to three of these chemicals: receptor McOr3 is sensitive to (S)-2-methyl-1-butanol; McOr20 is sensitive to (2S,3R)-2,3-hexanediol; and McOr5 is sensitive to 2-phenylethanol. McOr3 and McOr20 are also sensitive to structurally-related chemicals that are pheromones of other cerambycid beetles, suggesting that orthologous receptors may be present across many cerambycid species. These Ors are the first to be functionally characterized from any species of beetle and lay the groundwork for understanding the evolution of pheromones within the Cerambycidae.

A comparison of trap type and height for capturing cerambycid beetles (Coleoptera)

Wood-boring beetles in the family Cerambycidae (Coleoptera) play important roles in many forest ecosystems. However, increasing numbers of invasive cerambycid species are transported to new countries by global commerce and threaten forest health in the United States and worldwide. Our goal was to identify effective detection tools for a broad array of cerambycid species by testing some known cerambycid attractants and a pheromone in different trap designs placed across a range of habitats. We compared numbers and species richness of cerambycid beetles captured with cross-vane panel traps and 12-unit Lindgren multiple-funnel traps, placed either at ground level (1.5 m high) or canopy level (approximately 3-10 m high), at eight sites classified as either residential, industrial, deciduous forest, or conifer forest. We captured 3,723 beetles representing 72 cerambycid species from 10 June to 15 July 2010. Species richness was highest for the subfamilies Cerambycinae and Lamiinae, which accounted for 33 and 46% of all species captured, respectively. Overall, the cross-vane panel traps captured approximately 1.5 times more beetles than funnel traps. Twenty-one species were captured exclusively in traps at one height, either in the canopy or at ground level. More species were captured in hardwood sites (59 species) where a greater diversity of host material was available than in conifer (34 species), residential (41 species), or industrial (49) sites. Low numbers of beetles (n < 5) were recorded for 28 of the beetle species. The number of species captured per week ranged from 49 species on 21 June to 37 species on 12 July. Cross-vane panel traps installed across a vertical gradient should maximize the number of cerambycid species captured.

Blending synthetic pheromones of cerambycid beetles to develop trap lures that simultaneously attract multiple species

We evaluated attraction of cerambycid beetle species to blends of known cerambycid pheromones to determine whether such blends could be used as effective trap lures for detecting and monitoring multiple species simultaneously. Pheromone-baited traps captured 1,358 cerambycid beetles of which 1,101 (81.1%) belonged to three species in the subfamily Cerambycinae: Neoclytus acuminatus (F.), Neoclytus mucronatus (F.), and Xylotrechus colonus (F.). Beetles of these species were significantly attracted to synthetic blends that contained their pheromone components (isomers of 3-hydroxy-2-hexanone, 2,3-hexanediol, or both), despite the presence of pheromone components of different species, including other isomers of 2,3-hexanediol, (E/Z)-6,10-dimethyl-5,9-undecadien-2-yl acetate, and citral. In some cases, attraction was partially inhibited by the pheromone components of heterospecific species, whereas for N. acuminatus, attraction was completely inhibited when blends contained (2R*,3S*)-hexanediol, the racemic mixture of diastereomers of its pheromone, (2S,3S)-hexanediol. Among the remaining beetles captured were three species in the subfamily Lamiinae: Astyleiopus variegatus (Haldeman), Graphisurus fasciatus (Degeer), and Lepturges angulatus (LeConte). All three lamiine species were previously known to be attracted to (E/Z)-6,10-dimethyl-5,9-undecadien-2-yl acetate and were captured in significant numbers by blends containing that compound. Our results suggest that different types of cerambycid pheromones can be combined to create effective multispecies lures for use in surveillance programs that target exotic cerambycid species.

New Staphylinidae (Coleoptera) records with new collection data from New Brunswick and an addition to the fauna of Quebec: Staphylininae

Forty-four species of Staphylininae are newly reported from New Brunswick, bringing the total number of species known from the province to 126. Quedius criddlei (Casey) is reported for the first time from Quebec. Bisnius cephalotes (Gravenhorst) is removed from the faunal list of New Brunswick due to a lack of supporting voucher specimens. Additional locality data are presented for seven species either recently recorded from the province or with few previous records and little habitat data. We provide the first documented records of Atrecus americanus (Casey), Quedius erythrogaster Mannerheim, Quedius labradorensis labradorensis Smetana, Quedius plagiatus (Mannerheim), and Neobisnius terminalis (LeConte) from New Brunswick. Collection and habitat data are presented and discussed for all species.

New Coleoptera records from New Brunswick, Canada: Cerambycidae

Five species of Cerambycidae, Acmaeops discoideus (Haldeman), Anelaphus villosus (Fabricius), Phymatodes species (CNC sp. n. #1), Sarosesthes fulminans (Fabricius), and Urgleptus signatus (LeConte) are newly recorded for New Brunswick, Canada. All but Acmaeops villosus are new to the Maritime provinces. Phymatodes testaceus (Linnaeus) is removed from the faunal list of the province as a result of mislabeled specimens, records of Phymatodes maculicollis LeConte are presented confirming the presence of this species in New Brunswick, and the first recent records ofNeospondylis upiformis (Mannerheim) are presented. Additional records are given for the recently recorded Phymatodes aereus (Newman), indicating a wider distribution in the province. Collection data, habitat data, and distribution maps are presented for each species.

Efficacy of Fluon conditioning for capturing cerambycid beetles in different trap designs and persistence on panel traps over time

Fluon PTFE is a fluoropolymer dispersion applied as a surface conditioner to cross-vane panel traps to enhance trap efficiency for cerambycid beetles. We describe the results of three experiments to further optimize cerambycid traps of different designs and to test the effect of Fluon over time. We tested Fluon with Lindgren funnel and panel traps fitted with either wet or dry collection cups on catches of cerambycid beetles and how the effect of Fluon on panel traps persisted. Fluon-treated funnel traps with wet collection cups captured approximately 6x more beetles than the untreated funnel traps with wet collection cups. Untreated funnel traps with dry collection cups did not capture any beetles; however, Fluon-treated funnel traps with dry collection cups captured an average of four beetles per trap. Fluon-treated panel traps with wet collection cups captured approximately 9x more beetles than untreated panel traps with wet collection cups. Fluon-treated panel traps with dry collection cups captured approximately 11x more beetles than untreated panel traps with dry collection cups. The effect of Fluon on capturing cerambycid beetles did not decline after use in one or two field seasons. There was no significant difference in the number of beetles captured in freshly treated panel traps compared with traps that had been used for 1 or 2 yr. Fluon-treated traps captured nine species that were not captured in untreated traps. Conditioning both Lindgren funnel and panel traps with Fluon enhances the efficacy and sensitivity of traps deployed to detect exotic cerambycid species, or for monitoring threatened species at low population densities.

Evidence for limited spatial spread in an exotic longhorn beetle, Tetropium fuscum (Coleoptera: Cerambycidae)

The longhorn beetle Tetropium fuscum F. (Coleoptera: Cerambycidae) has become established in Nova Scotia, Canada, where it coexists with Tetropium cinnamopterum Kirby. The two Tetropium species share a similar ecological niche and use the same volatile cues for mate attraction. Exotic T. fuscum was introduced near Halifax, Nova Scotia, in approximately 1990, but the rate of its spread 20 yr later has not been documented. We report a large-scale, 3-yr study that investigates the distribution of T. fuscum relative to its site of introduction. Traps baited with male-produced pheromone and host volatiles were used to estimate the relative abundance of the two Tetropium species. Adult T. fuscum emerged 1-2 wk earlier than T. cinnamopterum each year between 2008 and 2010. The spatial distribution of T. fuscum was characterized by a sharp decline in abundance in relation to its point of introduction, up to a threshold distance of approximately 80 km beyond which T. fuscum is rare in comparison with native T. cinnamopterum. The restricted range of T. fuscum 20 yr after its introduction may be attributed to limited dispersal of adults or reproductive failures of low-density populations. The distribution of T. fuscum seemed stable between 2008 and 2010. In 1 of 3 yr, the abundance of T. cinnamopterum increased with the distance to the site of introduction of T. fuscum, which suggests competitive interactions between the two Tetropium species.

A male-produced aggregation pheromone of Monochamus alternatus (Coleoptera: Cerambycidae), a major vector of pine wood nematode

The beetle Monochamus alternatus Hope (Coleoptera: Cerambycidae) is an efficient vector of pine wood nematode, the causal pathogen of pine wilt disease, that has resulted in devastating losses of pines in much of Asia. We assessed the response of adult M. alternatus to 2-(undecyloxy)-ethanol, the male-produced pheromone of the congeneric M. galloprovincialis Dejean, in field experiments in Fujian Province, People's Republic of China. Both sexes of M. alternatus were attracted to lures consisting of 2-(undecyloxy)-ethanol combined with the host plant volatiles alpha-pinene and ethanol. A follow-up experiment showed that 2-(undecyloxy)-ethanol was synergized by both ethanol and alpha-pinene. Coupled gas-chromatography mass-spectrometry analyses of volatiles sampled from field-collected beetles of both sexes revealed that 2-(undecyloxy)-ethanol was a sex-specific pheromone component produced only by males. The combination of 2- (undecyloxy) -ethanol with ethanol and/or alpha-pinene will provide a valuable and badly needed tool for quarantine detection, monitoring, and management of M. alternatus.

Effect of chirality, release rate, and host volatiles on response of Tetropium fuscum (F.), Tetropium cinnamopterum Kirby, and Tetropium castaneum (L.) to the aggregation pheromone, fuscumol

The male-produced aggregation pheromones of Tetropium fuscum (F.) and T. cinnamopterum Kirby were identified as (2S,5E)-6,10-dimethyl-5,9-undecadienol by chemical analysis, synthesis, electronantennography, and field trapping; the compound is here renamed "fuscumol". The effect of fuscumol chirality, alone or with host volatiles, and fuscumol release rate on Tetropium spp. was tested in field-trapping experiments in Nova Scotia and Poland. Both (S)-fuscumol and racemic fuscumol synergized trap catches of male and female T. fuscum, T. cinnamopterum, and T. castaneum (L.) when combined with a blend of host monoterpenes and ethanol. Without added host volatiles, fuscumol was either unattractive (in Nova Scotia) or only slightly so (in Poland). (R)-Fuscumol, alone or in combination with host volatiles, did not elicit increases in trap capture of any Tetropium species, relative to the controls. Fuscumol synergized attraction of both sexes to host volatiles, thus indicating it acts as an aggregation pheromone. Sex ratio was often female-biased in traps baited with fuscumol plus host volatiles, and was either unbiased or male-biased in traps with host volatiles alone. In traps with host volatiles and racemic fuscumol, mean catches of Tetropium species were unaffected by fuscumol release rates ranging from 1 to 32 mg/d. The attraction of three different Tetropium species to the combination of (S)-fuscumol and host volatiles suggests that cross-attraction may occur where these species are sympatric, and that reproductive isolation possibly occurs via differences in close-range cues. These results have practical applications for survey and monitoring of T. fuscum, a European species established in Nova Scotia since at least 1980, and for early detection of T. castaneum, a European species not presently established in North America.

Treating panel traps with a fluoropolymer enhances their efficiency in capturing cerambycid beetles

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.

Identification and field activity of a male-produced aggregation pheromone in the pine sawyer beetle, Monochamus galloprovincialis

The pine sawyer beetle, Monochamus galloprovincialis, is a pest of pine trees in Europe and North Africa. Previously considered a secondary pest of stressed and dying trees, it is now receiving considerable attention as a vector of the pine wood nematode, Bursaphelenchus xylophilus, the causal agent of a lethal wilting disease in susceptible species of pines. Adult beetles are attracted to traps baited with a kairomone blend consisting of a host volatile, alpha-pinene, and two bark beetle pheromone components, ipsenol and 2-methyl-3-buten-2-ol. More recently it has been shown that mature male M. galloprovincialis produce a pheromone that attracts mature females in a laboratory bioassay. Here, volatiles were collected from mature male and female M. galloprovincialis, and a compound produced specifically by mature males was identified as 2-undecyloxy-1-ethanol from its gas chromatographic retention times, its mass spectrum, and by comparison with synthetic standards. The naturally-derived and synthetic compounds elicited electroantennographic responses from both females and males. Sealed polyethylene vials and polyethylene sachets were shown to be effective dispensers with zero-order release, the latter giving a higher release rate than the former. In two field tests, multiple-funnel traps baited with synthetic 2-undecyloxy-1-ethanol caught both female and male M. galloprovincialis, with higher catches at the higher release rate. This compound also synergized the attractiveness of the kairomone blend, the combined mixture catching 80-140% more beetles than the sum of the catches to each bait separately and luring up to two beetles/trap/d in a moderate-density population. We conclude that 2-undecyloxy-1-ethanol is a male-produced aggregation pheromone of M. galloprovincialis. This is the first example of a sex-specific compound in the cerambycid subfamily Lamiinae with significant behavioral activity in the field at a range sufficient to make it a useful trap bait. The possible roles of this pheromone in the chemical ecology of M. galloprovincialis and its potential use in pine wilt disease management are discussed.

Attraction of Anoplophora glabripennis to male-produced pheromone and plant volatiles

The male-produced pheromone of Anoplophora glabripennis (Motschulsky) (Coleoptera: Cerambycidae), which is an equal blend of 4-(n-heptyloxy)butan-1-ol and 4-(n-heptyloxy)butanal, was used in laboratory bioassays and in the greenhouse to determine its potential for attracting A. glabripennis adults. In modified "walking wind tunnels," virgin females were most attracted to the alcohol component, and virgin males were repelled by the pheromone blend at the lowest and highest amounts offered. Y-tube olfactometer bioassays also showed that females were significantly more attracted to the pheromone and its components than males were. However, males were more attracted to plant volatiles than females. Of 12 plant volatiles tested, delta-3-carene and (E)-caryophyllene were highly attractive to males, whereas (Z)-3-hexenyl acetate was repellent to males. Combining the male pheromone blend with (-)-linalool alone or with (Z)-3-hexen-1-ol attracted significantly more males than did the pheromone alone. We tested four trap designs in our quarantine greenhouse with eight different lures. The Intercept Panel traps and the hand-made screen sleeve traps caught more beetles than the Plum Curculio traps and Lindgren funnel traps. Intercept traps worked best when baited with male blend and (Z)-3-hexen-1-ol, whereas screen sleeve traps were most attractive when baited with (-)-linalool. Our findings provide evidence of the attractiveness of the A. glabripennis male-produced pheromone and suggest that it has a role in mate-finding. It is also a first step toward the development of an efficient trap design and lure combination to monitor A. glabripennis infestations in the field.