Exploring the Nature of Arhopalus ferus (Coleoptera: Cerambycidae: Spondylidinae) Pheromone Attraction.

Cerambycid species of the Spondylidinae subfamily are distributed worldwide and are known for being prolific invaders that infest conifers. In New Zealand, Arhopalus ferus (Mulsant), the burnt pine longhorn beetle, is well-established and requires monitoring at high-risk sites such as ports, airports, and sawmills as part of the requirements to meet pine log export standards set by the New Zealand Ministry of Primary Industries (MPI). Currently, its surveillance relies on traps baited with host volatiles (i.e., ethanol and α-pinene). We used volatile collections from adult beetles, electroantennograms, and field trapping bioassays to identify the pheromones emitted by the burnt pine longhorn beetle A. ferus and their effects on its behaviour. We show that A. ferus males emit mainly (E)-fuscumol and geranylacetone, as well as the minor components, α-terpinene and p-mentha-1,3,8-triene, and that all four compounds elicit a dose-dependent response in antennae of both sexes. Traps baited with the binary combination of geranylacetone plus fuscumol captured significantly more female A. ferus than did unbaited traps in two of three field experiments. α-Terpinene did not affect A. ferus trap catches and effects of p-mentha-1,3,8-triene on trap catch were not determined. Our findings provide further evidence of the use of fuscumol and geranylacetone as aggregation-sex pheromones by longhorn beetles in the Spondylidinae subfamily, and suggest that their deployment in survey traps may improve the efficacy of A. ferus monitoring in New Zealand and elsewhere.

Field Test of the Propheromones of the Whitemarked Tussock Moth (WMTM) Orgyia leucostigma (J.E. Smith) (Lepidoptera: Erebidae).

The whitemarked tussock moth (WMTM), Orgyia leucostigma (J.E. Smith) (Lepidoptera: Erebidae), is an economic pest in Nova Scotia, Canada, where it undergoes periodic outbreaks defoliating several tree species of economic value, including balsam fir, Abies balsamea (L.) Miller (Pinaceae). Herein is described a releasing device for the WMTM sex pheromone (Z,Z)-6, 9-heneicosadien-11-one based on a rubber septum, which converts pheromone precursors, such as acetals, namely (Z,Z)-11,11-dimethoxy-6,9-heneicosadiene and (Z,Z)-6,9-heneicosadien-11-one ethylene ketal, to the pheromone itself by the action of acetic acid and releases it over time. The pheromone is unstable in nature and, consequently, lures made with this compound will only attract WMTM for a day or two. The two pheromone precursors, however, are more stable, and are converted slowly into the pheromone by acetic acid impregnated in the releasing device, or by acidic conditions in the environment. The two pheromone precursors were synthesized in 2019 using a modified, previously published approach. Field trapping studies conducted from 2019-22 showed that traps baited with rubber septa loaded with either (Z,Z)-11,11-dimethoxy-6,9-heneicosadiene by itself or (Z,Z)-6,9-heneicosadien-11-one ethylene ketal plus acetic acid consistently caught significantly more WMTM than traps baited with blank septa in most experiments.

Courtship behavior and identification of a sex pheromone in Ibalia leucospoides (Hymenoptera: Ibaliidae), a larval parasitoid of Sirex noctilio (Hymenoptera: Siricidae).

BACKGROUND: Ibalia leucospoides (Hymenoptera: Ibaliidae) is a larval parasitoid that has been widely introduced as a biological control agent for the invasive woodwasp,Sirex noctilio (Hymenoptera: Siricidae) in the Southern Hemisphere. In this study, the courtship behavior and identificaion of sex pheromones are described for I. leucospoides under laboratory conditions. METHODS: For courtship behavior, both sexes were observed in a wire mesh observation cylinder (75 cm length ×10 cm diameter) for 15 minutes. The female body washes were analyzed using Gas Chromatography- Electroantennographic Detection (GC-EAD). Then the EAD-active compounds were tentatively identified using GC-Mass Spectrometry (GC-MS) and examined in olfactometer assays. RESULTS: The courtship behavior included rhythmic lateral movements, mounting, head-nodding cycles in males, and wing-fanning in females. GC-EAD analysis of female body washes with male antennae revealed seven compounds which elicited antennal responses, four of which are straight-chain alkanes (C23, C25, C26, and C27). The identities of these alkanes were confirmed by matching the retention times, mass spectra, and male antennal activity to those of commercially obtained chemicals. In olfactometer assays, a blend of the four straight-chain alkanes was attractive to I. leucospoides males, and there was no response to blends that lacked any of these four compounds. Female body wash was no more attractive than the four-component blend. The ratios of EAD-active components differ between hydrocarbon profiles from males and females. CONCLUSION: This study is the first investigation of cuticular hydrocarbons in the family Ibaliidae. It provides evidence that the ubiquitous alkanes (C23, C25, C26, and C27) in sex-specific ratios attract I. leucospoides males.

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.

Impact of Horizontal Edge-Interior and Vertical Canopy-Understory Gradients on the Abundance and Diversity of Bark and Woodboring Beetles in Survey Traps.

Semiochemical-baited intercept traps are important tools used to collect information about the presence/absence and population dynamics of forest insects. The performance of these tools is influenced by trap location along both horizontal edge-interior and vertical understory-canopy gradients. Consequently, the development of survey and detection programs requires both the development of effective traps and semiochemical lures but also deployment protocols to guide their use. We used field trapping experiments to examine the impact of both horizontal edge-interior and vertical understory-canopy gradients and their interactions with the species richness and abundance of Buprestidae, Cerambycidae and Curculionidae. Both gradients had significant effects on the diversity and abundance of all three families collected in traps and the pattern of gradient effects differed between the two experiments. In the first experiment, traps were deployed along transects involving large (>100 m) forest gaps and in the second experiment traps transected small (ca. 15 m) forest gaps. These results were consistent with the idea that gradient effects on the abundance and diversity of these three families of forest Coleoptera are context dependent. The results of this study suggest that monitoring programs for bark and woodboring beetles should deploy traps at multiple locations along both vertical understory-canopy and horizontal edge-interior gradients.

Semiochemical and Communication Ecology of the Emerald Ash Borer, Agrilus planipennis (Coleoptera: Buprestidae).

Knowledge of buprestid chemical ecology is sparse but the appearance of the invasive pest Agrilus planipennis Fairmaire in North America has provided the impetus to study in detail the semiochemistry and ecology of this important buprestid. The macrocyclic lactone (3Z)-12-dodecenolide [(3Z)-lactone] is identified as a key antennally-active compound that is produced by females and attracts males. Though a weak trap attractant alone, when combined with the host kairomone (3Z)-hexenol and the important visual cue of a green canopy trap, significant increases in male trap capture occur, thus defining (3Z)-lactone as both a sex pheromone of A. planipennis as well as the first and only known buprestid pheromone. The non-natural stereoisomer (3E)-12-dodecenolide and the saturated analog, 12-dodecanolide also exhibit mimetic activities towards male A. planipennis, suggesting a notable plasticity in this pheromonal structural motif. Efficient synthetic routes to these compounds have been developed. A series of fluoro-12-dodecanolides has also been synthesized containing CF2 groups as a strategy to bias the conformational space accessed by these macrolides and to assess if the analogs may act as mimetics for 12-dodecanolide pheromones associated in A. planipennis. These compounds also afford a unique opportunity to study the binding affinities of lactone surrogates with A. planipennis chemosensory proteins and olfactory receptors. Some progress has also been made in identifying the genes involved in the reception, processing and degradation of volatiles in this invasive insect. It is now evident that the behavior and ecology of A. planipennis involves a complex pattern of sensory modalities, including visual, tactile, olfactory and potentially acoustic components. Earlier reviews focused on studies of attractive host volatiles in development of a trapping system for early detection and visual and contact phenomena in A. planipennis mate finding. This review will update the semiochemistry and chemical ecology of A. planipennis and discuss studies on chemistry and behavior that have identified female-produced pheromone components and host kairomones.

Spruce Budworm (Lepidoptera: Tortricidae) Oral Secretions II: Chemistry.

As sessile organisms, plants have evolved different methods to defend against attacks and have adapted their defense measures to discriminate between mechanical damage and herbivory by insects. One of the ways that plant defenses are triggered is via elicitors from insect oral secretions (OS). In this study, we investigated the ability of second-instar (L2) spruce budworm [SBW; Choristoneura fumiferana (Clemens)] to alter the volatile organic compounds (VOCs) of four conifer species [Abies balsamea (L.) Mill., Picea mariana (Miller) B.S.P., Picea glauca (Moench) Voss, Picea rubens (Sargent)] and found that the emission profiles from all host trees were drastically changed after herbivory. We then investigated whether some of the main elicitors (fatty acid conjugates [FACs], ß-glucosidase, and glucose oxidase) studied were present in SBW OS. FACs (glutamine and glutamic acid) based on linolenic, linoleic, oleic, and stearic acids were all observed in varying relative quantities. Hydroxylated FACs, such as volicitin, were not observed. Enzyme activity for ß-glucosidase was also measured and found present in SBW OS, whereas glucose oxidase activity was not found in the SBW labial glands. These results demonstrate that SBW L2 larvae have the ability to induce VOC emissions upon herbivory and that SBW OS contain potential elicitors to induce these defensive responses. These data will be useful to further evaluate whether these elicitors can separately induce the production of specific VOCs and to investigate whether and how these emissions benefit the plant.

Spruce Budworm (Lepidoptera: Tortricidae) Oral Secretions I: Biology and Function.

The potential roles of the oral secretions (OS) of spruce budworm (SBW; Choristoneura fumiferana Clemens) larvae and factors that may affect the volume of OS disgorged were investigated in the laboratory. Experiments revealed that diet-fed SBW larvae readily disgorge OS when induced ("milked"), with minimal overall cost to their development and eventual pupal weight. Exposure of conspecific larvae to OS throughout larval development negatively affected survival and male pupal weight; however, male development time was faster when exposed to OS. Female pupal weight and development time were not affected. Preliminary experiments suggested that OS had a repellent effect on a co-occurring herbivore, the false hemlock looper, Nepytia canosaria (Walker). OS produced by larvae that fed on three host tree species and on artificial diet significantly increased the grooming time of ants (Camponotus sp.), indicating that SBW OS have an anti-predator function. The volume of OS is significantly greater in L6 than in L4 or L5, with the volume produced by L6 depending on weight and age as well as feeding history at time of milking. These findings indicate that SBW OS function as both an intra- and interspecific epideictic pheromone and as an anti-predator defensive mechanism, while incurring minimal metabolic costs.

Effects of Pheromone Release Rate and Trap Placement on Trapping of Agrilus planipennis (Coleoptera: Buprestidae) in Canada.

The emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), is a devastating insect pest in its introduced range. A trapping system that increases trap catches or detection rates in low-density populations would be beneficial for survey programs. Five trapping experiments were conducted to investigate factors influencing capture rates of male beetles on dark green traps baited with the A. planipennis pheromone, (3Z)-dodecen-12-olide ((3Z)-lactone), plus the green leaf volatile, (3Z)-hexenol. Low doses (0.001-1.0 mg) of (3Z)-lactone + (3Z)-hexenol did not consistently increase captures of male A. planipennis. In other experiments, mean captures of males were significantly higher on traps baited with a moderate dose (3.0 mg/septum) of (3Z)-lactone + (3Z)-hexenol, compared with lower doses (0.001, 0.1, and 1.0 mg) or (3Z)-hexenol alone. Next, we demonstrated that addition of (3Z)-lactone to traps baited with (3Z)-hexenol resulted in significantly greater increases in male captures when pairs of traps were placed on the same tree, than when traps were placed on adjacent trees. Moreover, significantly more A. planipennis were captured on pheromone-baited traps placed in the southern versus northern aspect of the crown. These results highlight the importance of experimental set-up for elucidating lure treatment effects and also suggests the (3Z)-lactone may be more active at close range. Our findings increase our understanding of the pheromone ecology of this species and lend support toward the use of dark green traps baited with 3.0 mg (3Z)-lactone + (3Z)-hexenol deployed in the south aspect of the canopy for detection programs for this insect.

Steps in the biosynthesis of fuscumol in the longhorn beetles Tetropium fuscum (F.) and Tetropium cinnamopterum Kirby.

Fuscumol [(2S,5E)-6,10-dimethyl-5,9-undecadien-2-ol] was recently identified as the male-produced aggregation pheromone of the brown spruce longhorn beetle, Tetropium fuscum (F.), and the eastern larch borer, Tetropium cinnamopterum Kirby. Several other species use this homoterpenoid alcohol motif, its ketone, or its acetate as part of their pheromone system. Investigation of the biosynthesis of this compound in these two Tetropium species demonstrated that geranylacetone [(5E)-6,10-dimethyl-5,9-undecadien-2-one] and farnesol [(2E,6E)-3,7,11-trimethyl-2,6,10-dodecatrien-1-ol] are both intermediates in this process. This was accomplished by applying deuterium-labeled geranylacetone and deuterium-labeled farnesol in separate experiments to the abdominal sterna of live T. fuscum and T. cinnamopterum and analyzing the deuterium labeling in the fuscumol and geranylacetone emitted by the insects with solid-phase microextraction (SPME) and GC/MS analysis. Deuterium labeling studies also showed that nerolidol[(3S,6E)-3-hydroxy-3,7,11-trimethyl-1,6,10-dodecatriene] and 2,3-epoxyfarnesol are not intermediates in fuscumol or geranylacetone synthesis in T. fuscum or T. cinnamopterum. Tissue-specific expression of T. fuscum farnesyl diphosphate synthase (TfFPPS), an enzyme expected to provide a key fuscumol precursor, was measured. TfFPPS transcripts were relatively abundant in male midguts, but were also present at significant levels in other tissues.

Attraction of Agrilus planipennis (Coleoptera: Buprestidae) to a volatile pheromone: effects of release rate, host volatile, and trap placement.

Attraction of emerald ash borer, Agrilus planipennis Fairmaire, to a volatile pheromone was demonstrated in three field experiments using baited green sticky traps. A dose-response curve was generated for male A. planipennis to increasing release rates of (3Z)-dodecen-12-olide ((3Z)-lactone) in combination with the green leaf volatile, (3Z)-hexenol. Only the lowest release rate (<2.50 µg/d) of (3Z)-lactone significantly increased captures of male A. planipennis, as compared with traps baited with (3Z)-hexenol alone. Effect of trap height, (3Z)-lactone, and (3Z)-hexenol and their interactions on the trap capture of A. planipennis was determined in a factorial experiment. Number of males per trap was significantly and positively affected by (3Z)-lactone, (3Z)-hexenol, and trap height whereas number of females per trap was affected by trap height only; none of the interactions were significant. As predicted, the greatest mean catch of males was in traps baited with (3Z)-lactone and (3Z)-hexenol placed high in the canopy. Electroantennogram tests on the bark volatile, 7-epi-sesquithujene, demonstrated the ability of male and female A. planipennis antennae to detect and respond to this compound, particularly the (+)-7-epi-sesquithujene isomer. Results from an olfactometer bioassay and field testing did not demonstrate attraction of either males or females to (+)-7-epi-sesquithujene. These data increase our understanding of the pheromone ecology of the invasive emerald ash borer, provide further confirmation of the behavioral activity of the female-produced lactone pheromone, and should increase the ability to detect A. planipennis infestations where they are present.

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.

Contact sex pheromones identified for two species of longhorned beetles (Coleoptera: Cerambycidae) Tetropium fuscum and T. cinnamopterum in the subfamily Spondylidinae.

Male Tetropium fuscum (F.) and T. cinnamopterum Kirby mated with live and dead (freeze-killed) conspecific females upon antennal contact, but did not respond to dead females after cuticular waxes were removed by hexane rinsing. Significantly fewer males of each species attempted to copulate with live or dead heterospecific females than with conspecifics, indicating that mate recognition was mediated by species-specific contact sex pheromones in the female's cuticular hydrocarbons. GC/MS analysis of T. fuscum elytra identified n-alkanes and mono-methyl branched alkanes of which 11-methylheptacosane and 3- and 5-methyltricosanes were dominant in females. Full male responses, including copulatory behavior, were restored with application of enantiomerically pure synthetic (S)-11-methyl-heptacosane at 40 µg/female (one female equivalent) but not with racemic or (R)-11-methyl-heptacosane. The cuticular hydrocarbons on T. cinnamopterum elytra included 11-methyl-heptacosane as well as n-alkanes, methyl-branched alkanes, mono-alkenes, and (Z, Z)-6, 9-alkadienes. (Z)-9-pentacosene, (Z)-9-heptacosene, and 11-methyl-heptacosane were female dominant, but only (Z)-9-pentacosene elicited precopulatory behaviors in conspecific males at levels similar to those behaviors elicited by unrinsed females, but elicited copulation in fewer than half of males. At female equivalent dosages (10 µg), neither (Z)-9-heptacosene nor (S)-11-methyl- heptacosane elicited responses in males that were significantly different from those responses to a rinsed female but when applied together, the proportion of males responding was significantly increased. 11-methyl-heptacosene is thus a contact pheromone component common to both species, which may explain the heterospecific mating attempts by some males.

Evidence for a volatile pheromone in Agrilus planipennis Fairmaire (Coleoptera: Buprestidae) that increases attraction to a host foliar volatile.

Analysis by gas chromatography/mass spectrometry (GC/MS) of volatiles from virgin female emerald ash borer, Agrilus planipennis Fairmaire confirmed the emission of (3Z)-lactone [(3Z)-dodecen-12-olide] but not its geometric isomer, (3E)-lactone [(3E)-dodecen-12-olide]. Gas chromatographic/electroantennographic (GC/EAD) analysis of synthetic (3Z)-lactone, which contained 10% (3E)-lactone, showed a strong response of male and female antennae to both isomers. EAG analysis with 0.01- to 100-µg dosages showed a positive dose response, with females giving significantly higher responses than males. In field experiments with sticky purple prism traps, neither lactone isomer affected catches when combined with ash foliar or cortical volatiles (green leaf volatiles or Phoebe oil, respectively). However, on green prism traps, the (3Z)-lactone significantly increased capture of male A. planipennis when traps were deployed in the canopy. Captures of males on traps with both (3E)-lactone and (3Z)-hexenol or with (3Z)-lactone and (3Z)-hexenol were increased by 45-100%, respectively, compared with traps baited with just (3Z)-hexenol. In olfactometer bioassays, males were significantly attracted to (3E)-lactone, but not the (3Z)-lactone or a 60:40 (3E):(3Z) blend. The combination of either (3E)- or (3Z)-lactone with Phoebe oil was not significantly attractive to males. Males were highly attracted to (3Z)-hexenol and the (3Z)-lactone + (3Z)-hexenol combination, providing support for the field trapping results. These data are the first to demonstrate increased attraction with a combination of a pheromone and a green leaf volatile in a Buprestid species.

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.

Sex pheromone chemistry and field trapping studies of the elm spanworm Ennomos subsignaria (Hübner) (Lepidoptera:Geometridae).

The elm spanworm, Ennomos subsignaria (Hübner), occurs throughout Canada and the eastern United States and can be a destructive forest pest on a wide range of deciduous trees. Gas chromatography/mass spectrometry (GC/MS) and coupled gas chromatographic-electroantennographic detection (GC/EAD) analysis of pheromone gland extracts, in combination with chemical synthesis and field trapping studies have identified (2S, 3R)-2-((Z)-oct-2'-enyl)-3-nonyl oxirane (hereafter Z6-9S, 10R-epoxy-19:H) as the female-produced sex pheromone. Significantly more male moths were captured between 1-100 microg loadings of this compound on red rubber septa in sticky traps compared to blank (unbaited) traps; catches then declined at higher dosages (500-1000 microg). The other isomeric enantiomer, (2R, 3S)-2-[(Z)-oct-2'-enyl]-3-nonyl oxirane (Z6-9R, 10S-epoxy-19:H), at a 10-microg dosage did not elicit trap capture. The likely precursor to the active epoxide, (Z, Z)-6, 9-nonadecadiene ((Z, Z)-6, 9-19:H), identified in virgin female sex pheromone glands, did not elicit trap capture either, and inhibited trap capture when combined with the active epoxide. Racemic 2-((Z)-oct-2'-enyl)-3-nonyl oxirane showed no significant difference in trap capture compared with Z6-9S, 10R-epoxy-19:H, indicating that the opposite enantiomer was not antagonistic. The addition of the EAD-active diene epoxide enantiomers (2S, 3R)-2-[(Z, Z)-octa-2', 5'-dienyl]-3-nonyl oxirane or (2R, 3S)-2-[(Z, Z)-octa-2', 5'-dienyl]-3-nonyl oxirane in admixture with Z6-9S, 10R-epoxy-19:H (at 10% of the latter) did not enhance or decrease trap capture compared to Z6-9S, 10R-epoxy-19:H oxirane alone, so they are not likely pheromone components. This pheromone, impregnated in rubber septa at less than 100-microg dosage, can now be used as a trap bait to develop detection and monitoring strategies for this insect.