Ipsenol, Ipsdienol, Ethanol, and α-Pinene: Trap Lure Blend for Cerambycidae and Buprestidae (Coleoptera) in Pine Forests of Eastern North America

Predators attracted to combination of bark beetle pheromones and host kairomones in pine forests of southeastern United States

In 2006, we evaluated the effects of combining lures releasing pine host kairomones (ethanol + α-pinene) with lures releasing bark beetle pheromones (ipsenol + ipsdienol) on trap catches of predators associated with bark and woodboring beetles in Florida, Georgia, Louisiana, and Virginia. Catches in traps baited with all 4 compounds were greater than those in traps baited with either binary blend for the common predators Thanasimus dubius (F.) (Coleoptera: Cleridae), Temnoscheila virescens (F.) (Coleoptera: Trogossitidae), Aulonium tuberculatum LeConte (Coleoptera: Zopheridae), and Lasconotus spp. (Coleoptera: Zopheridae). The same was true for: Enoclerus nigripes (Say) (Coleoptera: Cleridae) at 2 of 3 locations; Platysoma cylindricum (Paykull) (Coleoptera: Histeridae) at 3 of 4 locations; and Corticeus spp. (Coleoptera: Tenebrionidae) at 2 of 6 locations. In contrast, the addition of ethanol + α-pinene to traps baited with ipsenol + ipsdienol reduced catches of Platysoma attenuatum LeConte (Coleoptera: Histeridae) at 2 of 4 locations.

The longhorn beetles (Coleoptera: Cerambycidae) of Kentucky with notes on larval hosts, adult nectar use, and semiochemical attraction

The longhorn beetle fauna of Kentucky has long been overlooked in the literature with revisions and historic publications reporting few records from the state. Here, we document the occurrence of 222 species of Cerambycidae in Kentucky, with 140 new state records. For each species, we summarize its distribution (overall and in the state), the counties, years, and months in which it has been collected, collecting methods, what collections house the specimens, larval host plants, adult flower visitation, chemical lure attraction, recent taxonomic changes, and other pertinent information about the species. Using this dataset, the bias-corrected Chao1 species richness estimator predicted that 241 species should be found in Kentucky, indicating that our sampling is nearly comprehensive. Additionally, we provide a list of 42 species that have been found in at least one neighboring state and the distance from the closest record of the species to Kentucky; among this candidate list are 11 species known from within 50 km of the state. This checklist remedies the historical oversight of Kentucky cerambycid diversity in the literature, and we hope it will serve as a resource for future collectors, particularly the information on chemical lure attraction, which has not been summarized to this extent for any other state to date.  

Neuroecology of Alcohol Preference in Drosophila

In this review, we highlight sources of alcohols in nature, as well as the behavioral and ecological roles that these fermentation cues play in the short lifespan of Drosophila melanogaster. With a focus on neuroethology, we describe the olfactory detection of alcohol as well as ensuing neural signaling within the brain of the fly. We proceed to explain the plethora of behaviors related to alcohol, including attraction, feeding, and oviposition, as well as general effects on aggression and courtship. All of these behaviors are shaped by physiological state and social contexts. In a comparative perspective, we also discuss inter- and intraspecies differences related to alcohol tolerance and metabolism. Lastly, we provide corollaries with other dipteran and coleopteran insect species that also have olfactory systems attuned to ethanol detection and describe ecological and evolutionary directions for further studies of the natural history of alcohol and the fly.

Scale-dependent contribution of host-specificity and environmental factors to wood-boring longhorn beetle community assemblage in SW China

Longhorn beetles are extremely rich wood-boring insects possessing larvae that feed on the xylem of trees and/or lianas, which have detrimental effects on plants; in turn, the hosting plants may play a fundamental role in shaping the longhorn beetle community assemblage. However, factors determining the community assemblage of wood-boring longhorn beetles, particularly along the multiple spatial scales is still in need of further exploration. In this study, we designed an experiment across several spatial scales (from local to macro scales) from tropical to temperate climate gradients in Yunnan province, southwest China to examine to what extend the attributes of host-specificity is shaping the community assemblage along different spatial scales. This study concludes that (1) the wood-boring longhorn beetles showed attributes of host-specificity to a certain degree at the community level, (2) biotic (host plant specificity) and abiotic (climatic gradients) factors jointly shaped community composition of this species along the multiple spatial scales, (3) biotic interactions have a prominent effect on the community composition of this species at local-scale while macroclimatic gradients impose the major control on it at macro-scale. Thus, this study highlights the significance of host specificity in affecting the wood-boring longhorn beetle community assemblage, particularly at local scales.

Maximizing Bark and Ambrosia Beetle (Coleoptera: Curculionidae) Catches in Trapping Surveys for Longhorn and Jewel Beetles

Bark and ambrosia beetles are commonly moved among continents within timber and fresh wood-packaging materials. Routine visual inspections of imported commodities are often complemented with baited traps set up in natural areas surrounding entry points. Given that these activities can be expensive, trapping protocols that attract multiple species simultaneously are needed. Here we investigated whether trapping protocols commonly used to detect longhorn beetles (Coleoptera: Cerambycidae) and jewel beetles (Coleoptera: Buprestidae) can be exploited also for detecting bark and ambrosia beetles. In factorial experiments conducted in 2016 both in Italy (seminatural and reforested forests) and Canada (mixed forest) we tested the effect of trap color (green vs purple), trap height (understory vs canopy), and attractive blend (hardwood-blend developed for broadleaf-associated wood-boring beetles vs ethanol in Italy; hardwood-blend vs softwood-blend developed for conifer-associated wood-boring beetles, in Canada) separately on bark beetles and ambrosia beetles, as well as on individual bark and ambrosia beetle species. Trap color affected catch of ambrosia beetles more so than bark beetles, with purple traps generally more attractive than green traps. Trap height affected both beetle groups, with understory traps generally performing better than canopy traps. Hardwood-blend and ethanol performed almost equally in attracting ambrosia beetles in Italy, whereas hardwood-blend and softwood-blend were more attractive to broadleaf-associated species and conifer-associated species, respectively, in Canada. In general, we showed that trapping variables suitable for generic surveillance of longhorn and jewel beetles may also be exploited for survey of bark and ambrosia beetles, but trapping protocols must be adjusted depending on the forest type.

Sulcatol: Enantiospecific Attractant for Monarthrum mali (Coleoptera: Curculionidae: Scolytinae), Leptostylus asperatus (Coleoptera: Cerambycidae) and Associated Predators

In 2014-2019, we conducted six experiments in north-central Georgia in an attempt to verify the aggregation pheromone response of the ambrosia beetle Gnathotrichus materiarius (Fitch) (Coleoptera: Curculionidae: Scolytinae: Scolytini: Corthylina) to sulcatol known to be produced by male G. materiarius; we failed to catch any G. materiarius. However, we did find that another corthyline ambrosia beetle species Monarthrum mali (Fitch) was attracted to (R)-(-)-sulcatol, whereas the longhorn beetle Leptostylus asperatus (Haldeman) (Coleoptera: Cerambycidae: Lamiinae) was attracted to (S)-(+)-sulcatol. Attraction of both species was unaffected by the respective antipodes. Ethanol enhanced attraction of both species to traps baited with sulcatol. In at least one experiment, attraction to ethanol-baited traps was enhanced by sulcatol for Xylosandrus crassiusculus (Motschulsky), Xyleborus spp., and Hypothenemus spp. but reduced for Cnestus mutilatus (Blandford) (Coleoptera: Curculionidae: Scolytinae). Additionally, traps baited with ethanol and racemic sulcatol [50% (S)-(+): 50% (R)-(-)] caught the greatest numbers of four species of beetle predators: Coptodera aerata Dejean (Coleoptera: Carabidae), Colydium lineola Say (Coleoptera: Zopheridae), Madoniella dislocata (Say), and Pyticeroides laticornis (Say) (Coleoptera: Cleridae). Ethanol but not sulcatol attracted Temnoscheila virescens (F.) (Coleoptera: Trogossitidae). Information on interspecific relationships within forested communities may help us to better determine the roles of these species in maintaining stable and resilient forested ecosystems.

Multiple-Lure Surveillance Trapping for Ips Bark Beetles, Monochamus Longhorn Beetles, and Halyomorpha halys (Hemiptera: Pentatomidae)

Invasions by insects introduced via international trade continue to cause worldwide impacts. Surveillance programs using traps baited with host volatiles and pheromones can detect incursions of nonnative species. We report on two experiments executed to determine if attractants for several insect species can be combined without compromising trap catches and detection ability of target species. In the first experiment, we tested the effect of bark beetle pheromones (plus α-pinene) and trap contact with foliage on trap catches of the brown marmorated stink bug Halyomorpha halys Stål (Hemiptera: Pentatomidae) in traps baited with a mixture of bisabolenes and methyl (E,E,Z)-2,4,6-decatrienoate. Trap capture of H. halys adults was greater in traps not in contact with foliage, and the bark beetle pheromones ipsenol and ipsdienol did not affect trap capture of H. halys. In the second experiment, we tested the effects of multi-lure interactions among the primary host attractants α-pinene and ethanol, and the pheromones monochamol, ipsenol, ipsdienol, lanierone, and the H. halys compounds, on trap captures of various forest and agricultural insect pests. Specifically, we targeted Monochamus spp. (Coleoptera: Cerambycidae), Ips spp. (Coleoptera: Scolytinae) and H. halys. We found that a combination of all lures did not catch significantly lower numbers of Monochamus carolinensis Olivier, Monochamus scutellatus Say (Coleoptera: Cerambycidae), and Ips pini Say (Coleoptera: Scolytidae) than lure combinations missing components although removal of both lanierone and ipsdienol somewhat increased catches of Ips grandicollis Eichhoff (Coleoptera: Curculionidae). Our results support the use of traps baited with a full combination of these attractants in surveillance programs. This should reduce costs and increase detection rates of a wider range of conifer forest pests and H. halys.

Behavioral Responses of Pityophthorus juglandis (Coleoptera: Curculionidae: Scolytinae) to Volatiles of Black Walnut and Geosmithia morbida (Ascomycota: Hypocreales: Bionectriaceae), the Causal Agent of Thousand Cankers Disease

Thousand cankers disease (TCD) is a pest complex formed by the association of the walnut twig beetle (WTB), Pityophthorus juglandis Blackman (Coleoptera: Curculionidae: Scolytinae), with the fungal pathogen Geosmithia morbida Kolařík, Freeland, Utley and Tisserat (Ascomycota: Hypocreales: Bionectriaceae). Current monitoring and detection efforts for WTB rely on a pheromone lure that is effective over a limited distance while plant- and fungal-derived volatiles that may facilitate host location remain poorly understood. In this study, we test the hypothesis that adult beetles are attracted to volatiles of black walnut, Juglans nigra L. (Juglandaceae), and the pathogen, G. morbida. We measured the response of beetles to head-space volatiles collected from leaves and stems of 12 genotypes of black walnut and found genotypic variation in the attractiveness of host trees to adult WTB. Volatile profiles of the most attractive genotypes contained more α-pinene and β-pinene, and adult beetles were attracted to both of these compounds in olfactometer bioassays. In bioassays, we also demonstrated that adult WTB are attracted to volatiles of G. morbida. These findings suggest that, in addition to the aggregation pheromone, dispersing WTB potentially use host plant and fungal volatiles to locate suitable larval hosts. Finally, we conducted a field experiment to determine the extent to which ethanol, a common attractant for bark beetles, and limonene, a known bark beetle repellent, influence the behavior of adult WTB to pheromone-baited traps. Although ethanol did not increase trap capture, WTB were repelled by limonene, suggesting that this compound could be used to manipulate and manage WTB populations.

Blends of Pheromones, With and Without Host Plant Volatiles, Can Attract Multiple Species of Cerambycid Beetles Simultaneously

Pheromone components of cerambycid beetles are often conserved, with a given compound serving as a pheromone component for multiple related species, including species native to different continents. Consequently, a single synthesized compound may attract multiple species to a trap simultaneously. Furthermore, our previous research in east-central Illinois had demonstrated that pheromones of different species can be combined to attract an even greater diversity of species. Here, we describe the results of field bioassays in the northeastern, midwestern, southeastern, south-central, and southwestern United States that assessed attraction of cerambycids to a 'generic' pheromone blend containing six known cerambycid pheromone components, versus the individual components of the blend, and how attraction was influenced by plant volatiles. Nineteen species were attracted in significant numbers, with the pheromone blend attracting about twice as many species as any of the individual components. The blend attracted species of three subfamilies, whereas individual components attracted species within one subfamily. However, some antagonistic interactions between blend components were identified. The plant volatiles ethanol and α-pinene usually enhanced attraction to the blend. Taken together, these experiments suggest that blends of cerambycid pheromones, if selected carefully to minimize inhibitory effects, can be effective for sampling a diversity of species, and that plant volatiles generally enhance attraction. Such generic pheromone blends may serve as an effective and economical method of detecting incursions of exotic, potentially invasive 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.

Interactions between Ethanol, syn-2,3-Hexanediol, 3-Hydroxyhexan-2-one, and 3-Hydroxyoctan-2-one Lures on Trap Catches of Hardwood Longhorn Beetles in Southeastern United States

The effectiveness of a four-component "super lure" consisting of ethanol (E) and the cerambycid pheromones syn-2,3-hexanediol (D6), racemic 3-hydroxyhexan-2-one (K6), and racemic 3-hydroxyoctan-2-one (K8) on trap catches of Cerambycidae (Coleoptera) was determined in southeast United States with seven trapping experiments in 2011-2013. We captured 74 species of longhorn beetles in our three-year study. Ethanol significantly increased the mean catches of seven species and increased the number of cerambycid species detected. Traps with the "super lure" were effective for 8 of 13 species of Cerambycidae previously shown to be attracted to binary combinations of ethanol plus one of the three pheromones. However, the "super lure" was less effective for the remaining five species with catch reductions of 40-90% compared with combinations of ethanol and one or two of the pheromones. For example, K6 + K8 lures reduced catches of Anelaphus villosus (F.) in traps with E + D6 by 90%. Similarly, catches of Anelaphus pumilus (Newman) in traps with E + K6 + D6 were reduced by 50% with the addition of K8. Catches of Knulliana cincta (Drury) in traps with K6 + K8 lures were interrupted by D6, an effect negated by the addition of ethanol. Given the interruptive effects on trap catches of some species when lures are combined in a single trap, developing optimal lure blends to maximize detection efficacy will be a challenge for managers of detection programs for non-native invasive species of longhorn beetles.

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.

Pine Sawyers (Coleoptera: Cerambycidae) Attracted to α-Pinene, Monochamol, and Ipsenol in North America

Detection tools are needed for Monochamus species (Coleoptera: Cerambycidae) because they are known to introduce pine wilt disease by vectoring nematodes in Asia, Europe, and North America. In 2012-2014, we examined the effects of the semiochemicals monochamol and ipsenol on the flight responses of the sawyer beetles Monochamus carolinensis (Olivier), Monochamus clamator (LeConte), Monochamus mutator LeConte, Monochamus notatus (Drury), Monochamus obtusus Casey, Monochamus scutellatus (Say), and Monochamus titillator (F.) complex (Coleoptera: Cerambycidae) to traps baited with α-pinene. Experiments were set in pine forests in New Brunswick and Ontario (Canada), and Arizona, Georgia, Michigan, Montana, Oregon, South Carolina, Utah, and Washington (United States). In brief, 40 traps were placed in 10 blocks of 4 traps per block per location. Traps were baited with: 1) α-pinene; 2) α-pinene + monochamol; 3) α-pinene + ipsenol; and 4) α-pinene + monochamol + ipsenol. Monochamol increased catches of six species and one species complex of Monochamus with an additive effect of ipsenol for five species and one species complex. There was no evidence of synergy between monochamol and ipsenol on beetle catches. Monochamol had no effect on catches of other Cerambycidae or on any associated species of bark beetles, weevils, or bark beetle predators. We present a robust data set suggesting that the combination of α-pinene, ipsenol, and monochamol may be a useful lure for detecting Monochamus species.