Paper Abstract (2000-2004)

73 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 contents in blend compositions. 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.
Key Words: Sex pheromone, lepidopteran attractant, Noctuidae, Plusiinae, (Z)-7-dodecenyl acetate, (Z)-5-decenyl acetate, (Z)-9-tetradecenyl acetate, reproductive isolation

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

Biston robustum Butler (Geometridae: Lepidoptera), a polyphagous defoliator, multiplied on Hachijo-jima Island in 1997-98. 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-nonadecadine (IV) in a ratio of 13:2:70:15. The structure of III was further 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 some 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 the male attraction.
Key Words: female sex pheromones, Lepidoptera, Geometridae, Ennominae, epoxynonadecene, epoxynonadecadiene, chiral epoxide, chiral HPLC, dimethyl disulfide (DMDS) adduct

75 Regulation of Sex Pheromone Biosynthesis in Three Plusiinae Moths: Macdunnoughia confusa, Anadevidia peponis, and Chrysodeixis eriosoma.

Virgin females of M. confusa, A. peponis, and C. eriosoma secrete (Z)-7-dodecenyl acetate as a common main pheromone component. Their pheromone titers decreased after decapitation, and increased in the decapitated females after injection of a synthetic hormone, pheromone biosynthetic activating neuropeptide (PBAN) of Bombyx mori. In addition, an extract of brain-subesophageal ganglion complexes of each Plusiinae species activated pheromone biosynthesis in decapitated females of not only the corresponding species, but also that of Mamestra brassicae. These results indicate that pheromone biosynthesis of the three Plusiinae species is also controlled by a PBAN-like substance. However, the Plusiinae females exceptionally contained remarkable amounts of the pheromone even 1 day after decapitation. Since it has been reported that pheromones completely disappear at least 1 day after decapitation in females of many other lepidopteran species including B. mori and M. brassicae, a different mechanism is likely regarding the regulation of the studied Plusiinae pheromone biosynthesis. Furthermore, an incorporation experiment with a labeled pheromone precursor, D₉-(Z)-7-dodecenoic acid, showed that moderate biosynthesis still proceeded in the pheromone glands of M. confusa females 1 day after decapitation, providing an evidence why complete disappearance of the pheromone was not observed in the females which otherwise lacked a source of the pheromonotropic neuropeptide.
Key Words: sex pheromones, biosynthesis regulation, PBAN, neuropeptide hormone, deuterium incorporation

76 Optically Active 1'-Acetoxychavicol Acetate and Its Positional Isomers: Synthesis and Repellent Effect against Adzuki Bean Weevil.

1'-Acetoxychavicol acetate (1a), identified from the rhizomes of a Zingiberaceae plant as an anti-ulcer and insecticidal material, and its positional (meta and ortho) isomers were synthesized from hydroxybenzaldehydes. These racemic mixtures were resolved by HPLC equipped with a chiral column (Chiralpak AS or AD), and the absolute configuration of the separated enantiomers was studied with the corresponding 1'-hydroxy derivatives. Examination of the ¹H NMR data of their esters with (S)- and (R)-α-methoxy-α-(trifluoromethyl)phenylacetic acids by a modified Mosher's method indicated that the dextrorotatory enantiomers with a shorter R_t possess the R configuration, while the levorotatory enantiomers with a longer R_t possess the same S configuration as natural 1a. Both enantiomers of each compound showed almost the same insecticidal activity against the adzuki bean weevil (ABW). On the other hand, the (S)-enantiomers exhibited a stronger repellent effect against ABW females than the (R)-enantiomers, while a similar effect by the two stereoisomers was observed against the males. The number of eggs laid on adzuki beans was efficiently decreased when the beans were treated with the (S)-enantiomers, especially with (S)-1a.
Key Words: Secondary metabolite, resolution by chiral HPLC, Mosher's method, repellency, oviposition inhibitor, insecticide

77 Posticlure: a Novel trans-Epoxide as a sex Pheromone Component of the Tussock Moth, Orgyia postica (Walker).

A single EAG-active component was found in a pheromone extract from virgin females of the tussock moth, Orgyia postica. This compound named posticlure possesses a trans-epoxy ring and was identified as (6Z,9Z,11S,12S)-11,12-epoxyhenicosa-6,9-diene by means of GC-MS, ¹H NMR and chiral HPLC analyses, and further chemical derivation followed by the GC-MS analysis. In a field test with the pheromone synthesized stereoselectively, the male moths were specifically attracted to the (11S,12S)-isomer but not to the antipode.

78 Mating Disruption of the Japanese Giant Looper in Tea Gardens Permeated with Synthetic Pheromone and Related Compounds.

The Japanese giant looper, Ascotis selenaria cretacea, is a serious defoliator of tea gardens in Japan. The females produce racemic (Z,Z)-6,9-cis-3,4-epoxynona-decadiene (epo3,Z6,Z9-19:H, main component) and (Z,Z,Z)-3,6,9-nonadecatriene (Z3,Z6,Z9-19:H, minor component). The orientation of the males to the synthetic pheromone placed in a trap was strongly disrupted by Z3,Z6,Z9-19:H or a mixture of its monoepoxy derivatives (epoxydiene mixture, EDM) impregnated in septa and placed around the trap. Based on this result, polyethylene tubes containing Z3,Z6,Z9-19:H or EDM were prepared and effect of these dispensers was examined in a field. Disruption of male orientation to synthetic pheromone traps was achieved in orchards permeated with Z3,Z6,Z9-19:H at dispenser density of 3000 and 5000 tubes/ha (release rate: 0.55-0.61 mg/day/tube) and with EDM at every tested dose, 250-5000 tubes/ha (release rate: 0.25-0.39 mg/day/tube). Furthermore, disruption of mating in tethered females was observed in these orchards; particularly, the mating was perfectly inhibited in the areas treated with EDM at 3000 and 5000 tubes/ha. This is the first formulation for the mating disruption of a geometrid pest.
Key Words: Mating disruption, sexual communication, orientation, Ascotis selenaria cretacea, sex attractant, epoxynonadecadiene, nonadecatriene, polyethylene dispenser

79 Synthesis and Characterization of Diepoxyalkenes Derived from (3Z,6Z,9Z)-Trienes, Lymantriid Sex Pheromones and Their Candidates.

All stereoisomers of three diepoxyalkenes (1-3) derived from (3Z,6Z,9Z)-trienes with a C₂₁, C₁₉, or C₁₈ straight chain, lymantriid sex pheromones and their candidates, were synthesized by further MCPBA oxidation of optically active epoxyalkadienes, and their chromatographic behaviors were examined on GC and LC equipped with achiral and chiral columns. Detailed inspection of their mass spectra indicated the following diagnostic ions for determining the chemical structures; m/z 128, 167, M-87, and M-85 for (Z)-cis-3,4-cis-6,7-diepoxy-9-enes (1), m/z 111, M-125, and M-69 for (Z)-cis-6,7-cis-9,10-diepoxy-3-enes (2), and m/z M-125 and M-139 for (Z)-cis-3,4-cis-9,10-diepoxy-6-enes (3). Mass chromatographic analysis monitoring these fragment ions revealed the existence of a new pheromonal compound,1 with a C₂₁ chain, in an extract from virgin females of a lymantriid species, Perina nuda F. Furthermore, 1-3 were converted into the corresponding DMDS adducts, which showed some characteristic ions fragmented at thiomethoxy groups reflecting the position of an original double bond.
Key Words: cis-Epoxides, sex pheromones, Lepidoptera, Lymantriidae, mass spectrometry, chiral HPLC, stereochemistry, diepoxyhenicosene, leucomalure

80 Identification of Epoxyhenicoxadiene and Novel Diepoxy Derivatives as Sex Pheromone Components of the Clear-Winged Tussock Moth Perina nuda.

Four EAG-active components (A-D) were found in the solvent extract of virgin females of the tussock moth, Perina nuda. The most abundant component (B, ca. 250 ng/female) was identified as (3Z,6S,7R,9Z)-6,7-eopxyhenicosa-3,9-diene by GC-MS analyses of the extract, chemical derivatization, and comparative chiral HPLC analyses. Minor components also elucidated were (3Z,9Z)-cis-6,7-epoxyicosa-3,9-diene (A); (3R,4S,6S,7R,9Z)-3,4-6,7-diepoxyhenicos-9-ene (C); and its (3S,4R,6S,7R)-isomer (D); with amounts of 0.4, 5 and 8 ng/female, respectively. Component B showed weak attractiveness to male moths in the field. The attractiveness was significantly enhanced by addition of component(s) C and/or D. No males were captured with either the antipode of component B or its mixtures with the minor components. In this field test, noctuid Hypocata rostrata males were also attracted with the synthetic P. nuda pheromone.
Key Words: Sex pheromone, Perina nuda, Lymantriidae, (3Z,6S,7R,9Z)-6,7-eopxyhenicosa-3,9-diene, (3R,4S,6S,7R,9Z)-3,4-6,7-diepoxyhenicos-9-ene, (3S,4R,6S,7R,9Z)-3,4-6,7-diepoxyhenicos-9-ene, sex attractant, Hypocata rostrata, Noctuidae.

81 Biosynthetic Pathway for Production of a Conjugated Dienyl Sex Pheromone of a Plusiinae Moth, Thysanoplusia intermixta.

Virgin females of Thysanoplusia intermixta (Lepidoptera; Noctuidae; Plusiinae) produce (5E,7Z)-5,7-dodecadienyl acetate as a main sex pheromone component. GC-MS analysis of the pheromone glands, which were treated with deuterated hexadecanoic, (Z)-11-hexadecenoic, and (Z)-7-dodecenoic acids, showed incorporation of the label into the dienyl component. Their incorporation rates confirmed that its biosynthesis proceeds in the following order; Δ11-desaturation of a C₁₆ acyl intermediate, chain shortening to a C₁₂ compound by β-oxidation, Δ5-desaturation to produce a 5,7-dienyl system, reduction of the acyl group, and acetylation. These deuterated precursors also converted into a minor pheromone component, (Z)-7-docecenyl acetate, which might be prepared by the same pathway except for the step of Δ5-desaturation. While deuterium incorporation into the dienyl acetate was not observed in the extracts treated with other labeled dodecenoic acids with (E)-5-, (Z)-6-, and (E)-7-double bonds, the corresponding dodecenyl acetates were produced. This result showed low substrate specificity of the enzymes for reduction and acetylation. Labeled (Z)-10-hexadecenoic acid was not converted into a dodecenyl acetate, indicating the high substrate specificity of the enzyme for β-oxidation.
Key Words: Pheromone biosynthesis, Conjugated diene, 5,7-Dodecadienyl acetate, Δ11-Desaturation, Δ5-Desaturation, Deuterated fatty acid, GC-MS analysis, Lepidoptera, Noctuidae

82 Sex Attractants for Moths of Vietnam: Field Attraction by Synthetic Lures Baited with Known Lepidopteran Pheromones.

Screening tests of synthetic lepidopteran sex pheromones were carried out at orchards in the Mekong Delta over an approximately two-year period starting from December 1998. Monoenyl acetates with a C₁₀-C₁₄ chain attracted six species distributed mainly in Southeast Asia: Adoxophyes privatana, Archips atrolucens, and Meridemis furtiva in the Tortricidae family and Argyrogramma signata, Spodoptera pectinicornis, and Zonoplusia ochreata in the Noctuidae family. These were in addition to three other noctuid species that had been attracted during previous field examinations within a temperate zone. Furthermore, male moths of three species belonging to the Cosmopterigidae, Gelechiidae, or Batrachedridae family were also caught by traps baited with acetates. On the other hand, trienes with a C₁₈-C₂₁ chain and their monoepoxides, which are stereotypes of pheromones secreted by females in the Geometridae family, failed to attract any geometrid males but attracted three Noctuidae species and four Arctiidae species.
Key Words: male attractants, monoenyl acetate, triene, epoxydiene, Lepidoptera, Tortricidae, Noctuidae, Plusiinae, Arctiidae

83 Identification of Sex Pheromone Components Secreted by Female Moths of Peridroma saucia (Noctuidae: Noctuinae).

The variegated cutworm, Peridroma saucia Hubner, is a lepidopteran pest of a large number of crops in Canada, the United States, and Europe. It was naturalized in Japan probably in the 1970s. Pheromone glands of the female moths include two components with electroantennographic activity in a ratio of 3:1. GC-MS analyses of the pheromone extracts untreated and treated with dimethyl disulfide revealed that the major component is (Z)-11-hexadecenyl acetate and the minor component is (Z)-9-tetradecenyl acetate. The synthetic pheromone was used to attract a large number of males in a vegetable field in Tokyo, which suggests that this species has already become a harmful pest in Japan.
Key Words: Lepidoptera; insect pheromones; attractants; monoenyl acetates; filed attraction

84 Synthesis and Acaricidal Activities of New 2-Polyfluorophenylbenzoazole Derivatives.

New 2-phenylbenzoazole derivatives, thirteen benzoxazoles and eight benzothiazoles, were synthesized, and their acaricidal activities were measured against the two-spotted spider mite (TSM). Some compounds with a polyfluorophenyl group were highly effective in killing the eggs (LC₅₀: < 50 ppm) with moderate lethal activity (LC₅₀: 150-200 ppm) against the adults. Among them, 2-(3-chloro-2,4,5-trifluorophenyl)-5-methylbenzoxazole was selected as the most promising candidate for an acaricide, and the effects of its concentrate were evaluated. This formulation achieved a high rate of mortality in the citrus red mite and a kelthane-resistant strain of TSM in addition to a common strain of TSM.
Key Words: Benzoxazole, benzothiazole, acaricidal activity, two-spotted spider mite, ovicide

85 Polyunsaturated Hydrocarbons in the Hemolymph: Biosynthetic Precursors of Epoxy Pheromones of Geometrid and Arctiid Moths.

Female moths of many species in Geometridae, Arctiidae and some other macrolepidopteran families produce epoxy pheromones, which are probably derived from polyunsaturated hydrocarbons. In order to understand a biosynthetic site, hemolymph from both sexes of two geometrid species, Ascotis selenaria cretacea and Hemerophila artilineata, and one arctiid species, Spilosoma imparilis, was shaken with n-hexane and the solvent extracts were analyzed by GC-MS. Each extract of the female hemolymph sex-specifically included polyunsaturated hydrocarbons corresponding to the pheromonal epoxy components in addition to many saturated hydrocarbons, but no epoxy compounds were detected in it. Based on this analysis, deuterated polyunsaturated hydrocarbons were injected into the abdomens of two geometrid females, and the labeled epoxy components were successfully yielded from the pheromone glands. This result indicated that the polyunsaturated hydrocarbons occurring in the female hemolymph were direct pheromone precursors, which might be produced outside of the pheromone gland, probably in oenocytes associated with abdominal epidermal cells or in the fat body, and transported to the pheromone gland via the hemolymph for their epoxidation and emission into an atmosphere.
Key Words: Sex pheromone biosynthesis, (3Z,6Z,9Z)-trienes, (6Z,9Z)-dienes, epoxydienes, hemolymph, cuticle, oenocyte, lipophorin, GC-MS analysis, Lepidoptera, Geometridae, Arctiidae

86 Synthesis and Characterization of Hexadecadienyl Compounds with a Conjugated Diene System, Sex Pheromone of the Persimmon Fruit Moth and Related Compounds.

Hexadecadiene-1-ol and the derivatives (acetate and aldehyde) with a conjugated diene system have recently been identified from a pheromone gland extract of the persimmon fruit moth (Stathmopoda masinissa), a pest insect of persimmon fruits distributed in East Asia. The alcohol and acetate showed their base peaks at m/z 79 in a GC-MS analysis by electron impact ionization, but the aldehyde produced a unique base peak at m/z 84, suggesting a 4,6-diene structure. To confirm this inference, four geometrical isomers of each 4,6-hexadecadienyl compound were synthesized by two different routes in which one of two double bonds was furnished in a highly stereoselective manner. Separation of the two isomers synthesized together by each route was facilely accomplished by preparative HPLC. Their mass spectra coincided well with those of natural components, indicating that they were available for use as authentic standards for determining the configuration of the natural pheromone. Furthermore, other hexadecadienyl compounds, including the conjugated diene system between the 3- and 10-positions, were synthesized to accumulate the spectral data of pheromone candidates. 5,7-Hexadecadienal interestingly showed the base peak at m/z 80; meanwhile, the base peaks of its alcohol and acetate were detected at m/z 79 like the corresponding 4,6-dienes. The base peaks of all 6,8-, 7,9-, and 8,10-dienes universally appeared at m/z 67 like 9,11-, 10,12-, and 13,15-dienes, the spectra of which have already been published. Although 3,5-hexadecadienal was not prepared, base peaks at m/z 67 and 79 were recorded for the alcohol and acetate, respectively.
Key Words: Sex pheromone; persimmon fruit moth; 4,6-hexadecadienyl acetate; 4,6-hexadecadienal; conjugated diene

87 Characterization of Geometrid Sex Pheromones by Electrospray Ionization Time-of-Flight Mass Spectrometry.

The utility of liquid chromatography combined with time-of-flight mass spectrometry (LC/TOF-MS) was demonstrated for studies on chiral unsaturated epoxy compounds, sex pheromones produced mainly by female moths in the family Geometridae. By electrospray ionization (ESI), each synthetic epoxyalkadiene derived from (Z,Z,Z)-3,6,9-triene with a C₁₈-C₂₃ straight chain showed three ion series of [M+NH₄]⁺, [M+H]⁺, and [M-OH]⁺ with high resolution and good sensitivity, indicating its molecular formula. In addition to these, characteristic fragment ions at m/z M-57 and M-71 for the 3,4-epoxides and at m/z M-123 and 123 for the 9,10-epoxides were detected, whereas the 6,7-epoxides did not produce fragment ions that reflected their structures. Monitoring these diagnostic ions during the LC/MS analysis of a gland extract, the natural sex pheromone of the mulberry looper was confirmed to be (Z,Z)-cis-9,10-epoxy-3,6-octadecadiene, which was separable from the other positional isomers on an ODS column. Furthermore, (Z,Z)-cis-3,4-epoxy-6,9-nonadecadiene secreted by the Japanese giant looper was analyzed with a chiral column, and the stereochemistry was determined directly.
Key Words: Liquid chromatography/mass spectrometry, electrospray ionization, insect pheromone, epoxyalkadiene, chiral HPLC

88 Sex Pheromone of the Persimmon Fruit Moth, Stathmopoda masinissa (Lepidoptera: Oecophoridae): Identification and Laboratory Bioassay of (4E,6Z)-4,6-Hexadecadienyl Compounds.

Three electroantennogram (EAG)-active components were detected by gas chromatography coupled to an electroantennographic detector (GC-EAD) analysis of a hexane extract of the pheromone glands of the persimmon fruit moth, Stathmopoda masinissa. These compounds were identified as (4E,6Z)-4,6-hexadecadienal (E4,Z6-16:Ald) and the corresponding acetate (E4,Z6-16:OAc) and alcohol (E4,Z6-16:OH) by mass spectral, GC retention time (RT), and microchemical test data. The characteristic base peak of the aldehyde at m/z 84 provided a crucial piece of information suggesting the possibility of a 4,6-diene structure. The (4E,6Z)-isomer elicited the strongest EAG responses among the four geometrical isomers of each synthetic 4,6-hexadecadienyl compound. In a laboratory bioassay, only E4,Z6-16:OAc elicited male moth behavioral activity significantly different from the control; the activity of the acetate was not affected by addition of the aldehyde and alcohol. A preliminary field trial confirmed that E4,Z6-16:OAc as a single component attracted male moths. The possible roles of E4,Z6-16:Ald and E4,Z6-16:OH as components of lures for field use remain to be determined.

91 Selectivity and neuroendocrine regulation of the precursor uptake by pheromone glands from hemolymph in geometrid female moths, which secrete epoxyalkenyl sex pheromones.

Macrolepidopteran female moths in families such as Geometridae produce epoxyalkenyl sex pheromones, which are biosynthesized via epoxidation of polyunsaturated hydrocarbons in their pheromone glands. The precursors, however, are expected to be produced outside of the pheromone glands, probably in oenocytes or in the fat body, and transported to the glands via hemolymph. Based on these facts, the selectivity of the epoxidation substrates and of the precursor uptake by pheromone glands was examined with two geometrid species, Hemerophila artilineata and Ascotis selenaria cretacea, using binary mixtures of deuterated precursors and their analogs, which were topically applied to the pheromone glands or injected into the abdomen. GC-MS measurements of pheromone extracts showed equal epoxidation of two polyenes, indicating a low selectivity for both processes, while the epoxidation proceeded at only one double bond specific to each species. This result makes it possible to conclude that the formation of species-specific epoxyalkenyl pheromones results from the rigid formation of polyunsaturated precursors and their epoxidation at a fixed position. Next, the neuroendocrine regulation of these processes was studied with in vivo and in vitro experiments using decapitated females. The epoxy pheromones disappeared completely within 36 h of decapitation, and epoxidation of the injected precursors was not detected in the decapitated females, which restarted the reaction by treatment with a pheromone biosynthesis-activating neuropeptide (PBAN). The precursors topically applied to glands of the decapitated females, however, were converted into epoxy pheromones without PBAN, indicating that this neuropeptide hormone accelerated the precursor uptake by pheromone glands but not the epoxidation already underway in the glands.

92 Lepidopteran Sex Pheromones. In "The chemistry of pheromones and other semiochemicals".

As a consequence of the diversity of Lepidoptera, including 150,000 described species, interesting species-specific sex pheromone systems are exhibited in this insect group. The quite varied pheromones, which have been identified from nearly 530 species from around the world, are classified into groups of Type I (75 %), Type II (15 %) and miscellaneous (10 %), according to their chemical structures. While new sex pheromones from about 60 lepidopteran species have been reported in the last five years utilizing GC-EAD, GC-MS, LC, and NMR, our information about the pheromones is still rudimentary, and these kinds of semiochemicals remain an exciting research target for natural product chemistry. In addition to the overview of their chemical structures, this chapter deals with current methods for their identification. Furthermore, an actual application of the synthetic pheromones for pest control is briefly introduced.