Sex pheromone of the saltmarsh caterpillar moth,Estigmene acrea

Three compounds have been identified as components of the sex pheromone emitted by females of the saltmarsh caterpillar moth,Estigmene acrea (Drury). These are (Z,Z)-9,12-octadecadienal (I), (Z,Z,Z)-9,12,15-octadecatrienal (II), and (Z,Z)-3,6-cis-9,10-epoxyheneicosadiene (III). In female tip extract they were found in a ratio of 1625, respectively, and in trapped female effluvia the ratio was 1627, respectively. Combinations of III with either I or II elicited sustained upwind flight in a wind tunnel, but none of these compounds by themselves did so. There is evidence that the antennal acceptor site for III is chiral.Lepidoptera: Arctiidae.Supported in part by the Rockefeller Foundation and by National Science Foundation Grants GB-38020 and PCM 78-13241.     

Sex pheromone components of the giant looper,Boarmia selenaria schiff. (Lepidoptera: Geometridae): Identification,synthesis, electrophysiological evaluation,and behavioral activity

(Z,Z)-6,9-cis-(3S,4R)-Epoxynonadecadiene9a and (Z,Z,Z)-3,6,9-nonadecatriene have been identified as sex pheromone components in female ovipositor extracts and effluvia of the geometridBoarmia selenaria. The identification was based on relative retention times on gas chromatographic columns, GC-MS, chemical enantioselective syntheses, EAG, wind-tunnel behavioral experiments, and field tests. A single female ovipositor extract contained an average of 42 ng of (Z,Z)-6,9-cis-3,4-epoxynonadecadiene and 2 ng of (Z,Z,Z)-3,6,9-nonadecatriene.EAG, wind-tunnel behavioral studies, and field tests demonstrated that maleB. selenaria exhibit preferential attraction for the (3S,4R)-enantiomer of (Z,Z)-6,9-cis-3,4-epoxynonadecadiene. Only in effluvia and ovipositor extracts of calling females was (Z,Z)-6,9-cis- 3,4-epoxynonadecadiene detected, whereas relatively high amounts of (Z,Z,Z)-3,6,9-nonadecatriene were found in noncalling females. Wind-tunnel behavioral studies showed that (Z,Z,Z)-3,6,9-nonadecatriene did not elicit any response in the males, and when tested in combination with a mixture of monoepoxynonadecadienes, (Z,Z,Z)-3,6,9-nonadecatriene decreased the observed behavioral responses. A possible precursor role for (Z,Z,Z)-3,6,9-nonadecatriene in the pheromonal system is discussed.     

Intraspecific variation and interspecific differences in sex pheromones of sibling species inCtenopseustis obliquana complex

The specific status ofCtenopseustis obliquana pheromone-types I, II, and III has been more fully examined. Females of types I and III produce a mixture of (Z)-8- and (Z)-5-tetradecenyl acetates (Z8-14:Ac, Z5-14: Ac). The previously reported different ratios of these two components in females of the two types (type I=8020, III=9010) have been reinvestigated. The median ratios of each type differed significantly, although there was some overlap in the ranges of these ratios. A field cage trial showed that males of type III are attracted to females of type I, so the observed differences may be ascribed to intraspecific variation. In contrast to females of types I or III, females of type II produce Z5-14Ac but no Z8-14Ac. The electroantennogram (EAG) profile of antennae of type II males shows a maximum response to Z5-14Ac, while the EAG profiles of types I and III show a strong response to Z8-14Ac. In wind tunnel tests using mixtures of these two compounds, type II males prefer blends consisting of all or mostly Z5-14: Ac, while type I males showed a preference to a mix of 70% Z8-14Ac plus 30% Z5-14Ac. We found that type I males are attracted to type I females when offered a choice between type I and type II females in a field cage test and that type II males similarly prefer type II females. Males of types I and II have specialist cells for Z8-14Ac and Z5-14Ac but differ with respect to relative densities of these cells and to further cell types responsive to other alkenyl acetates. Type IIC. obliquana is considered therefore a sibling species of types I and III. In addition, the amount of Z5-14Ac produced by type II females varied geographically. Females from the North Island produced significantly less (median=1.2 ng) Z5-14Ac than females from the South Island (median=2.2 ng). Type II populations in the North Island morphologically resembled sympatric type I, rather than type II from the South Island and are designated as type II (North Island). Type II (North Island) populations have so far been found only at Rukuhia (near Hamilton) and from Kerikeri. In contrast, type II populations are sympatric with type III populations over much of the South Island. In a field cage trial, males of types II and II (North Island) were attracted to females of both II and II (North Island). We tentatively ascribe the differences between type II and type II (North Island) to intraspecific variation.     

Novel sex pheromone components from the fall cankerworm moth,Alsophila pometaria

A sex pheromone extract from fall cankerworm moths,Alsophila pometaria, attracted conspecific males in field tests. Four EAG-active components were isolated from the extract and identified by GC-MS, highfield PMR spectroscopy, and microchemical techniques asn-nonadecane (I), (Z,Z,Z)-3,6,9-nonadecatriene (II), (Z,Z,Z,E)-3,6,9,11-nonadecatetraene (III), and (Z,Z,Z,Z)-3,6,9,11-nonadecatetrane (IV). Studies of the behavioral responses of male moths in a flight tunnel to the isolated components showed II, III, and IV were the major components of the sex pheromone. No sex pheromone behavioral responses were observed for I.Lepidoptera: Geometridae.issued as NRCC No. 22964.     

Differential recognition of geometric isomers by the boll weevil,Anthonomus grandis Boh. (Coleoptera: Curculionidae): Evidence for only three essential components in aggregation pheromone

For two decades, the aggregation pheromone of the boll weevil,Anthonomus grandis Boh. (Coleoptera: Curculionidae), was thought to consist of four compounds: I [(+)-(Z)-2-isopropenyl-1-methylcyclobutane ethanol]; II [(Z)-3,3-dimethyl-^I,-cyclohexane ethanol]; III [(Z)-3,3-dimethyl-^1,-cyclohexane acetaldehyde); and IV [(E)-3,3-dimethyl-^1,-cyclohexane acetaldehyde). Evidence is presented from behavioral and electrophysiological studies to show that only three of these components, I, II, and IV, are essential for attraction. Competitive field tests, in which each possible three-component blend was tested against the four-component mixture, demonstrated that omission of I, II. or IV resulted in decreased trap captures (P < 0.01). Trap captures by these blends lacking I, II, or IV resembled those by the hexane solvent alone in a similar experiment. However, omission of III did not significantly alter field attractiveness of the blend. Dosage-response curves constructed from electroantennogram responses of both males and females to serial dilutions of III, IV, and a 5050 mixture of the geometric isomers III and IV showed both sexes to be 10- to 100-fold more sensitive to IV than III. Data from the electrophysiological studies were consistent with a single acceptor type for the (E)-cyclohexylidene aldehyde, IV, for males, and possibly one or two acceptor types for III and IV for females. Possible roles for the (Z)-cyclohexylidene aldehyde, III, and implications for the pheromonal attractant currently used in boll weevil eradication/suppression programs are discussed.     

The female sex pheromone of sugarcane stalk borer,Chilo auricilius identification of four components and field tests

Four pheromonal components have been detected in ovipositor washings and volatiles from female sugarcane stalk borers,Chilo auricilius Dudgeon (Lepidoptera: Pyralidae), using combined gas chromatography-electroantennography. The components have been identified as (I) (Z)-7-do-decenyl acetate, (II) (Z)-8-tridecenyl acetate, (III) (Z)-9-tetradecenyl acetate, and (IV) (Z)-10-pentadecenyl acetate by comparison of their gas chromatographic behavior with that of synthetic standards. In field tests carried out in northern India during 1982–1984, a combination of II, III, and IV in their naturally occurring ratio (841) was shown to provide a highly attractive synthetic source for trap use. (Z)-7-Dodecenyl acetate was found to reduce catches of maleC. auricilius, both when dispensed with the other three components and when released from dispensers surrounding a trap baited with the other three components.     

Sex pheromone components of three species ofSemiothisa (Geometridae), (Z,Z,Z)-3,6,9-heptadecatriene and two monoepoxydiene analogs

Adult males ofSemiothisa signaria dispuncta (Walker) were attracted to field traps baited with (Z,Z,Z)-3,6,9-octadecatriene and (Z,Z)-6,9-cis-3,4-epoxy-octadecadiene. However, analyses of sex pheromone gland extracts of females of this species by GC-MS and by GC in combination with an electroantennograph detector (GC-EAD) showed the pheromone to be comprised of a mixture of the next lower homologs: (Z,Z,Z)-3,6,9-heptadecatriene and (Z,Z)-6,9-cis-3,4-epoxy-heptadecadiene. Blends of these two C₁₇ compounds were subsequently found to be more attractive to males in the field than the corresponding C₁₈ mixtures. Sex pheromones of two otherSemiothisa species were also found to contain C₁₇ components. (Z,Z,Z)-3,6,9-Heptadecatriene, detected by GC-EAD analysis of a female abdominal tip extract ofS. bicolorata (Fabricius), attracted conspecific males, and this attraction was significantly reduced by additions of (Z,Z)-6,9-cis-3,4-epoxyheptadecadiene, the major pheromone component ofS. signaria dispuncta, to the lure. (Z,Z)-3,9-cis-6,7-Epoxy-heptadecadiene was detected by GC-EAD analysis as the primary male antennal stimulatory component present in abdominal tip extracts ofS. ulsterata (Pearsall), and males of this species were attracted to traps baited with this epoxide. Each of these three C₁₇ compounds constitute previously unknown lepidopteran sex pheromone components. Blends of (Z,Z, Z)-3,6,9-heptadecatriene and (Z,Z)-3,9-cis-6,7-epoxyheptadecadiene attracted males of a fourth species,S. delectata Hulst, but no females of this species were obtained to permit analysis of its sex pheromone. The occurrence of (Z,Z,Z)-3,6,9-heptadecatriene inS. neptaria (Guenee) females was indicated by GC-MS analysis of an abdominal tip extract; however, no males were attracted to any of the fielded mixtures containing this hydrocarbon.     

Potential for evolution of resistance to pheromones: Interindividual and interpopulational variation in chemical communication system of pink bollworm moth

After an extensive examination of the release rates and blend ratios of pheromonal components emitted by field-collected femalePectinophora gossypiella (Saunders), we find no evidence of resistance to pheromones applied to cotton fields to disrupt mating. Females from fields with 3–5 years of exposure to disruptant pheromones as well as those from fields with only minimal exposure to disruptant pheromones emitted (Z,Z)-7,11-hexadecadienyl acetate at a rate of ca. 0.1 ng/min and (Z,E)7,11-hexadecadienyl acetate at ca. 0.06 ng/min. The ratio of pheromonal components was much less variable than the measured emission rate and was centered about a 61:39Z, Z to Z,E ratio. In contrast to the blend ratio emitted by females, the composition of the pheromonal blend used in monitoring populations and disrupting mating is centered about 50:50 Z,Z to Z.E. In general there was a remarkable consistency in the release rate and blend ratio among populations of females throughout southern California and those from a laboratory colony. It would appear that, although resistance to theP. gossypiella pheromone is still a very real possibility when it is used heavily in pest management as a mating disruptant, there are current agricultural practices and conditions which would hinder its development. Pectinophora gossypiella (Saunders), Lepidoptera: Gelechiidae.     

Aggregation pheromones of the flat grain beetle,Cryptolestes pusillus (Coleoptera: Cucujidae)

Aggregation pheromones were isolated fromCryptolestes pusillus (Schönherr), a coleopteran pest of stored products. Porapak Q-captured beetle and frass volatiles were fractionated by preparative gas-liquid chromatography. The fractions were bioassayed with an arena olfactometer and/or with a two-choice, pitfall olfactometer. Three biologically active, male-produced compounds eliciting aggregation behavior from adultC. pusillus were isolated and identified by spectroscopic methods as (Z)-3-dodecenolide (I), (Z)-5-tetradecen-13-olide (II), and (Z,Z)-3,6-dodecadienolide (III). Compound I was the major volatile produced and was active alone. Compound II was not active alone, but synergized the response to I. Compound III was active alone at higher concentrations, but did not significantly increase the response when added to the most active mixture of I and II, and so it is probably not part of the aggregation pheromone. Pheromone production increased dramatically when the insects were aerated on a food source.Research supported in part by the Natural Sciences and Engineering Research Council of Canada, Operating Grants A3881 and A3785, Strategic Grant 60958, and a Graduate Scholarship to J. G. Millar.     

Sex pheromone of the fall webworm moth,Hyphantria cunea

Three compounds have been identified as sex pheromone components produced by female fall webworm moths,Hyphantria cunea (Drury). These compounds are: (Z,Z)-9,12-octadecadienal (I), (Z,Z,Z)-9,12,15-octadecatrienal (II), and (Z,Z)-3,6-cis-9,10-epoxyheneicosadiene (III). The ratio of these compounds was approximately 5613, respectively, in female tip extracts prepared from U.S.S.R, insects and approximately 1821, respectively, in extracts from U.S. insects. The ratio in female effluvia trapped from U.S. insects was 1627, respectively. Compound III plus either I or II is effective in eliciting upwind flight in a wind tunnel. Compounds I, II, and III are also components of the sex pheromone system of the saltmarsh caterpillar moth,Estigmene acrea (Drury).Lepidoptera: Arctiidae.Part of this work was carried out under the sponsorship of the U.S.A.-U.S.S.R. Scientific Exchange Program and the U.S.S.R. Ministry of Agriculture. It was also supported in part by National Science Foundation grant PCM78-13241. These results were first disclosed at the EUCHEM Conference on Chemistry of Insects, held at Borgholm, Sweden, on August 13–17, 1979. We sadly note the passing away of our distinguished colleague and friend, Dr. A.S. Hill.     

Sex pheromone chemistry of the female tobacco budworm moth,Heliothis virescens

(Z)-11 -Hexadecenal (77–91%), (Z)-7-hexadecenal (0.1–2%), (Z)-9-hexadecenal (0.3–2%), hexadecanal (3–19%), (Z)-11-hexadecen-1-ol (1–5%), tetradecanal (1–3%), and (Z)-9-tetradecenal (1–3%) were identified from the heptane washes of the ovipositor of femaleHeliothis virescens (F.) females. In field bioassays, a 152-g mixture of these seven compounds deployed in an insect trap exceeded the attractiveness of 4 virgin femaleH. virescens for males and was 5–6 times more attractive than a mixture of (Z)-1 1-hexadecenal and (Z)-9-tetradecenal (virelure) that was previously reported as the sex pheromone of the species. Four of the seven compounds produced byH. virescens females are also produced byH. zea (Boddie). Specificity of pheromonal signals among the two species is ostensibly dependent upon one or more of the three additional compounds [tetradecanal, (Z)-9-tetradecenal, and (Z)-1 1-hexadecen-1-ol] produced by femaleH. virescens.     

Identification of female sex pheromone components of rice looper,Plusia festucae (L.), (Lepidoptera: Noctuidae)

The rice looper,Plusia festucae, is a defoliator of the rice plant. Chromatographic behavior, chemical reactions, and GC-MS analyses of the female sex pheromone revealed that the main component was (Z)-5-dodecenyl acetate (Z5–12: OAc, component I). The GC-MS analysis also indicated that the pheromone gland extract included another three monounsaturated components, (Z)-5-dodecen-l-ol (Z5–12: OH, component II), (Z)-7-tetradecenyl acetate (Z7–14: OAc, component III), and (Z)-7-tetradecen-l-ol (Z7–14: OH, component IV) in the following ratio: I:II:III:IV=100:6:15:1. In a paddy field, the mixture of synthetic I, II, and III in a ratio of 100:6:15 showed stronger attractancy than the virgin female, while the role of IV was unknown.     

Female sex pheromone of the pickleworm,Diaphania nitidalis (Lepidoptera: Pyralidae)

Heptane extracts of the ovipositors from pickleworm adults (Diaphania nitidalis) were found to contain (E)-11-hexadecenal along with proportionally smaller amounts of (Z)-11-hexadecenal, (E)- and (Z)-11-hexadecen-1-ol, hexadecanol, hexadecanal, and a trace amount of (E,Z)-10,12-hexadecadienal. Assays conducted in a flight tunnel and in the field showed that a synthetic mixture of the five unsaturated compounds elicited behavioral responses from pickleworm males that were indistinguishable from those elicited by extracts of the female or by mate-calling females. When any component was deleted from the set of five unsaturated compounds, the intensity and extent of male responses to the resulting mixtures were significantly attenuated. The female sex pheromone of the pickleworm resembles the pheromone of a congeneric species,D. hyalinata, but bioassays indicated that (E,E)-10,12-hexadecadienal, produced byD. hyalinata but not by the pickleworm, plays a role in pheromonal specificity.     

Identification of Sex Pheromones of Anadevidia peponis and Macdunnoughia confusa and Field Tests of Their Role in Reproductive Isolation of Closely Related Plusiinae Moths

Anadevidia peponis and Macdunnoughia confusa are defoliators of plants in the family Cucurbitaceae and Compositae, respectively, in Japan. GC-MS analyses of crude pheromone gland extracts treated with or without dimethyl disulfide indicated that females of A. peponis produced six monoene acetates and two monoene alcohols and that M. confusa females produced five monoene acetates. These components include (Z)-7-dodecenyl acetate as a major common constituent and three other acetates as minor common constituents. The minor constituents are quite different in blend composition. In addition, with (Z)-7-dodecenyl acetate, an indispensable component for male attraction is (Z)-5-decenyl acetate for A. peponis and (Z)-9-tetradecenyl acetate is essential for M. confusa. Field tests with synthetic lures showed synergistic effects of some other minor components and male attraction of three additional Plusiinae species, Macdunnoughia purissima, Ctenoplusia albostriata, and Chrysodeixis eriosoma, suggesting their reproductive isolation is based in part on pheromonal communication.     

Role of sex pheromone components in behavioral reproductive isolation betweenAutographa gamma (L.) and eitherTrichoplusia ni (Hübner) ORChrysodeixis chalcites (Esp.) (Lepidoptera: Noctuidae: Plusiinae)

The composition of theAutographa gamma sex pheromone was reexamined and only (Z)-7-dodecenyl acetate and (Z)-7-dodecenol were identified by capillary GC, GC-MS, and dimethyl disulfide derivatization and subsequent GC-MS analysis. The fatty acid content of the pheromone glands was also studied, and a series of saturated and unsaturated acids was identified. However, most of the related pheromonal compounds were not detected. The male response to the pheromone components was studied in a flight tunnel and compared with the response to calling females. The best synthetic baits evoked a response similar to that observed to the virgin females, but males spent significantly more time at calling females than at the synthetic baits. The preferred synthetic baits consisted of (Z)-7-dodecenyl acetate alone or of a blend with 5% (Z)-7-dodecenol. Increasing the relative amount of the alcohol caused a gradual reduction in male response, particularly in the last steps of the courtship sequence. The addition of the minor sex pheromone components of the sympatric Plusiinae species,Trichoplusia ni andChrysodeixis chalcites, to theA. gamma pheromone was also investigated in the flight tunnel. Some of these components exhibited a significantly antagonistic effect on theA. gamma male courtship behavior. The most potent antagonists were (Z)-5-dodecenyl acetate and (Z)-9-tetradecenyl acetate. The response ofA. gamma andT. ni males to conspecific and heterospecific females was also compared in the flight tunnel. WhereasA. gamma males were attracted only to their conspecific females, a small percentage ofT. ni males were also attracted toA. gamma females and 11% performed the whole courtship sequence.Contribution from the Agricultural Research Organization (ARO), No. 3459-E, 1992 series.     

Polyunsaturated hydrocarbons in the stable fly

Three triply-unsaturated hydrocarbons were identified from cuticular lipids of male and mixed-sex stable flies,Stomoxys calcitrans. The major compound, (Z,Z)-1,7,13-pentacosatriene, and two minor compounds, (Z,Z)-1,7,13-tetracosatriene and (Z,Z)-1,7,13-tricosatriene, were synthesized. Samples of male and female stable flies that differed in age, seasonality, geographic origin, rearing conditions of adults, and methods of extraction were analyzed for the presence of these triolefins. Females were found to have small quantities of the same C₂₅ triolefin, which appeared to be identical to that in males. No evidence was seen for attraction of males or females to natural or synthetic triolefins.Mention of a proprietary or commercial product does not constitute an endorsement by either the U.S. Department of Agriculture or the University of Florida.     

Evidence for Additional Pheromonal Components Mediating Oviposition Aggregation in Schistocerca gregaria

Oviposition responses of gregarious adult gravid females of the desert locust Schistocerca gregaria to sand previously used for oviposition by gregarious females (contaminated sand, with eggs and froth removed) and to sterilized sand (noncontaminated sand) were compared in bioassays. Gregarious females preferentially oviposited into contaminated sand. The number of egg pods laid by the females was found to correlate with the frequency of use of the contaminated sand for oviposition. Charcoal-trapped volatiles from the contaminated sand also elicited similar responses from gregarious females. Gas chromatography–electroantennographic detection (GC-EAD) analysis of the trapped volatiles revealed the presence of three electrophysiologically active compounds that were identified by GC-MS as (Z)-6-octen-2-one, (E,E)-3,5-octadien-2-one and its geometric isomer (E,Z)-3,5-octadien-2-one. The relative amounts of the three EAG-active compounds in the volatiles increased with consecutive oviposition by the gregarious females. These results indicate mediation of additional pheromonal components in the oviposition behavior of gregarious desert locust that are distinct from those that were previously identified in the froth volatiles.     

Identification of Chiral Sex Pheromone Secreted by Giant Geometrid Moth, Biston robustum Butler

Biston robustum Butler, a polyphagous defoliator, multiplied on Hachijo-jima Island in 1997–1998. Based on GC-MS data of authentic standards, an analysis of a pheromone gland extract of the females indicated that it included (Z,Z)-6,9–nonadecadiene (I), (Z,Z,Z)-3,6,9–nonadecatriene (II), cis-(Z)-6,7–epoxy-9–nonadecene (III), and cis-(Z,Z)-6,7–epoxy-3,9–nonadecadiene (IV) in a ratio of 13 : 2 : 70 : 15. The structure of III was confirmed by a GC-MS analysis of another extract treated with dimethyl disulfide (DMDS). This epoxymonoene was successfully converted into the corresponding DMDS adduct that showed diagnostic ions fragmented at an epoxy ring and at thiomethoxy groups reflecting the position of an original double bond. Furthermore, the 6S,7R configuration was assigned for the epoxy ring of III by chiral HPLC analysis. Field examination of synthetic lures revealed that the two epoxy compounds (III and IV) with the 6S,7R configuration were essential components and that the two unsaturated hydrocarbons (I and II) showed a synergistic effect on male attraction.     

Aggregation pheromones of the grain beetle,cryptolestes turcicus (Coleoptera: Cucujidae)

Two biologically active macrolides were isolated from Porapak Q-captured beetle and frass volatiles ofCryptolestes turcicus (Grouvelle) and identified spectroscopically as (Z,Z)-5,8-tetradecadien-13-olide (I) and (Z)-5-tetradecen-13-olide (II). Natural I was active alone and was synergized by inactive II. The pheromones were male-produced but attractive to both sexes. Pheromone production increased dramatically when insects were aerated on a food source. Pure (R)- and (S)-I were inactive, but mixtures of (R)- and (S)-I were active, the first reported instance of enantiomeric synergism in the Cucujidae.     

Analysis and field evaluation of volatile blend emitted by calling virgin females of beet armyworm moth,Spodoptera exigua (Hübner)

The volatile blend emitted by calling virgin beet armyworm females was collected and analyzed by capillary gas chromatography and mass spectrometry. Five compounds were detected and identified in this blend: (Z)-9-tetradecenyl acetate, (Z)-9-tetradecen-l-ol, (Z,E)-9,12-tetradecadienyl acetate (Z,Z)-9,12-tetradecadienyl acetate, and (Z)-l 1-hexadecenyl acetate. They were emitted in a ratio of 47.9 4.040.2 6.5 1.7, respectively. This five-component blend and several other blends with one or more components deleted were formulated on rubber septa to release the components in about the same ratios as the females. Field tests of these formulations in bucket traps indicated that a blend of (Z)-9 tetradecen-1-ol, (Z,E)-9,12-tetradecadienyl acetate, and (Z)-l 1-hexadecenyl acetate was most effective for trapping beet armyworm males and that (Z)-9-tetradecenyl acetate actually decreased trap captures. Blends that did not contain both (Z)-9-tetradecen-l-ol and (Z,E)-9,12-tetradecadienyl acetate were ineffective as trap baits.