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. 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 male, but attracted three Noctuidae species and four Arctiidae species.     

Major Sex Pheromone Component of Female Herald Moth Scoliopteryx libatrix is the Novel Branched Alkene (6Z,13)-Methylheneicosene

The major component of the female-produced sex pheromone of Scoliopteryx libatrix has been characterized by chemical analysis, synthesis, electrophysiological studies and field tests as (6Z,13)-methylheneicosene, probably the 13S-isomer. This is the first example of a branched chain alkene as a sex pheromone in the Noctuidae and is markedly different from the pheromones of other members of the family. The systematic position of S. libatrix, belonging to a monotypic genus of a one-member subfamily within the Noctuidae, may reflect the unusual structure of the sex pheromone.     

Comparative Studies of the Ability of Males to Discriminate Between Sexes in Caloglyphus spp.

Female sex pheromones that trigger the mounting behavior of conspecific males have been identified in four species of the genus Caloglyphus—C. polyphyllae, C. rodriguezi, and two unidentified species. Although the sex pheromones are distributed over both males and females, content ratios of female to male vary from 1.4 in Caloglyphus sp. MJ to 3.4 in C. polyphyllae, 6.3 in C. rodriguezi, and 8.4 in Caloglyphus sp. HP. In the former two species the sex pheromones are also detectable in nymphal stages as a major component, while the pheromones are found to be adult specific in the latter two species. Evaluation of the ability of males to recognize conspecific females revealed that males of all three species, except the Caloglyphus sp. MJ, could discriminate between females and males. We conclude that the differences in the amounts of the female sex pheromone function to facilitate in discrimination by males of conspecific females in the three species, while males of Caloglyphus sp. MJ cannot do this because the 1.4-fold difference is insufficient. It is suggested that the sex pheromone of Caloglyphus spp. might have evolved from a common compound, which originally functioned as a male sexual excitant, into the sex-specific compound that now functions to allow males to discriminate females from males.     

Effects of Sublethal Doses of Malathion on Responses to Sex Pheromones by Male Asian Corn Borer Moths, <Emphasis Type="Italic">Ostrinia furnacalis</Emphasis> (Guenée)

We evaluated the sublethal effects of malathion treatment on the behavioral responses of male Asian corn borers, Ostrinia furnacalis (Guenée), to their sex pheromones. Doses of malathion causing 1–50% mortality were topically applied to Asian corn borer male moths. The survivors were tested for behavioral and electroantennogram (EAG) responses to their sex pheromones. Sublethal doses of malathion affected males’ ability to locate a pheromone source. In wind tunnel tests, male moths treated with sublethal doses of malathion took 2.5 to 12 times as long to take flight as control moths. Malathion-treated male moths were 60–96% less likely to locate a sex pheromone source than control moths. Multiple linear regression analysis revealed that the proportions of males performing each key stage were significantly correlated with the doses of malathion, but not with the time since treatment. Sensitivity and specificity of perception to pheromones in male moths were also disrupted by sublethal doses of malathion. The EAG responses of males treated with malathion decreased 0.13 mV on average compared with control moths. In addition, the ratios of pheromone components that elicited the largest responses shifted from approximately 5:5 to 1:9 (E/Z) and 9:1. We conclude that treatment with sublethal doses of malathion significantly reduced the likelihood that male Asian corn borers could successfully locate a normal female releasing sex pheromones.     

Hydrocarbons with a homoconjugated polyene system and their monoepoxy derivatives: Sex attractants of geometrid and noctuid moths distributed in Japan

Although several sex pheromones of the family Geometridae have been characterized, investigations on Japanese species are limited. In order to obtain more information, screening using known sex pheromones and their analogs was carried out. The (Z,Z,Z)-3,6,9-triunsaturated and (Z,Z)-6,9-diunsaturated hydrocarbons with straight C¹⁹-C²¹ chains were synthesized by the Grignard coupling reaction as a key step starting from linolenic and linoleic acids, respectively. Oxidation of the homoconjugated trienes withm-chloroperoxybenzoic acid yielded a 111 mixture of three monoepoxy derivatives that could be separated by silica gel chromatography. The chemical structure of each positional isomer was confirmed using two-dimensional NMR techniques and MS measurements, which enabled characteristic fragment ions from the isomers to be identified. Field tests using lures incorporating only one of the above six hydrocarbons or nine epoxides were carried out in a forest in Tokyo. Consequently, attraction of male moths of 14 geometrid species in addition to four species in another family, the Noctuidae, was observed. It was concluded that hydrocarbons with a homoconjugated polyene system and the monoepoxy derivatives are important components of sex pheromones produced by Japanese lepidopterous insects, particularly the geometrid moths.     

New sex attractants for 35 tortricid and 4 other lepidopterous species,found by systematic field screening in the Netherlands

Most of the known sex attractants and pheromones found for Tortricidae attract species of the subfamily Tortricinae. In order to find more sex attractants for species of the subfamily Olethreutinae, about 60 one- and two-component lures were screened for attractancy in different biotopes in the Netherlands. Most of the chemicals tested were straight-chain dodecen-1-ols and their acetates. The species captured belonged to the following families and subfamilies: Tortricinae (5), Olethreutinae (30), Noctuidae (2), Gelechiidae (1), Gracillariidae (1). Some of the species captured are recorded as pest species in forestry:Epinotia tedella, Gypsonoma aceriana, Cydia strobilella, C. zebeana, Petrova resinella, Blastesthia turionella, andB. posticana.     

The Complete Mitochondrial Genome of the Pink Stem Borer, Sesamia inferens, in Comparison with Four Other Noctuid Moths

The complete 15,413-bp mitochondrial genome (mitogenome) of Sesamia inferens (Walker) (Lepidoptera: Noctuidae) was sequenced and compared with those of four other noctuid moths. All of the mitogenomes analyzed displayed similar characteristics with respect to gene content, genome organization, nucleotide comparison, and codon usages. Twelve-one protein-coding genes (PCGs) utilized the standard ATN, but the cox1 gene used CGA as the initiation codon; cox1, cox2, and nad4 genes had the truncated termination codon T in the S. inferens mitogenome. All of the tRNA genes had typical cloverleaf secondary structures except for trnS1(AGN), in which the dihydrouridine (DHU) arm did not form a stable stem-loop structure. Both the secondary structures of rrnL and rrnS genes inferred from the S. inferens mitogenome closely resembled those of other noctuid moths. In the A+T-rich region, the conserved motif "ATAGA" followed by a long T-stretch was observed in all noctuid moths, but other specific tandem-repeat elements were more variable. Additionally, the S. inferens mitogenome contained a potential stem-loop structure, a duplicated 17-bp repeat element, a decuplicated segment, and a microsatellite "(AT)(7)", without a poly-A element upstream of the trnM in the A+T-rich region. Finally, the phylogenetic relationships were reconstructed based on amino acid sequences of mitochondrial 13 PCGs, which support the traditional morphologically based view of relationships within the Noctuidae.     

Insect sex pheromones

The half-lives (tin1/2) of acetate sex pheromones andn-alkyl acetates were determined on either or both West Co. and Arthur H. Thomas Co. natural rubber septa. These septa gave equal half-lives. Thet _1/2 values covered a large range: e.g.,t _1/2 for decyl acetate was 5 days and that for pentadecyl acetate was 1353 days. The expected linear relationship between Int _1/2 versus the number of carbon atoms was found for the six acetates fromn-decyl to pentadecyl, but thet _1/2 of hexadecyl acetate was only 478 days. This nonlinearity in the plot is attributed to the presence of polymer cross-links which create molecular size cages and produce an effect similar to that produced in gel permeation chromatography wherein large molecules elute faster than smaller ones. Thet _1/2 of 4 monounsaturated acetates were close to thet _1/2 for the corresponding saturated acetates, but this relationship may not be general. The half-life of one nonconjugated diunsaturated acetate was much less than that for the corresponding monounsaturated acetate, whereas the half-life of another nonconjugated diunsaturated acetate was similar to the half-life of the corresponding monounsaturated acetate. Thet _1/2 values determined for the pheromones may be used to estimate evaporation rates, the length of time the evaporation rates will be within a given range, and, with multicomponent pheromones, the ratio of components in the vapor.Mention of proprietary products does not constitute an endorsement by the USDA.     

Identification of the Sex Pheromone of Sesamia cretica Lederer

By using solid phase micro-extraction and gas chromatography–mass spectrometry analyses, a sex pheromone blend for the stem borer, Sesamia cretica Lederer (Lepidoptera, Noctuidae), was identified as consisting of (Z)-9-tetradecen-1-ol (80%), (Z)-9-tetradecen-1-yl acetate (10%), and (Z)-11-hexadecen-1-ol (10%). The first two components had previously been discovered as attractants for S. cretica in field tests, but had not been identified in the female’s sex pheromone gland. A field-trapping trial showed that the three-component blend gave the highest catches of male S. cretica. This blend, in a sticky trap, was used to monitor a population of S. cretica in Iran, allowing the seasonal flight activity of this insect to be compared with that of a sympatric population of S. nonagrioides. The role of pheromones in the reproductive isolation of these species is discussed.     

2-Methylthiazolidine and 4-ethylguaiacol,male sex pheromone components of the cockroachNauphoeta cinerea (dictyoptera,blaberidae): A reinvestigation

InNauphoeta cinerea, male calling behavior is associated with sex pheromone release by the sternal glands. The male pheromone that attracts females from a distance is a mixture of 2-methylthiazolidine and 4-ethylguaiacol. It is active at very low concentrations, 0.05 and 0.01 ng, respectively. Two other compounds, 3-hydroxy-2-butanone and 2-methyl-2thiazoline, act at close range, keeping the female in the vicinity of the male. The function of the volatile pheromone and those of previously described contact pheromones are discussed in regard to their possible involvement in the establishment of male dominant-subordinate relationships.     

Mating Communication Systems of Four Plusiinae Species Distributed in Japan: Identification of the Sex Pheromones and Field Evaluation

The sex pheromones of four Plusiinae species in the family Noctuidae, Ctenoplusia albostriata (CA), Macdunnoughia purissima (MP), Syngrapha ain (SA), and Diachrysia stenochrysis (DS) were identified by GC-EAD and GC-MS analyses. These were subsequently evaluated by a series of field trials in different ecological habitats. CA females produced (Z)-5-decenyl acetate (I), (Z)-7-dodecenyl acetate (II), and (Z)-7-dodecen-1-ol (III) in a ratio of 2:100:13. While the antennae of CA males responded to all three components, neither I nor III was essential to capture males. The MP females produced II, III, and (Z)-5-dodecenyl acetate (IV) in a ratio of 100:80:20, and this blend captured the most MP males. Compounds II and III were also identified from SA females, and mixtures ranging from 4:1 to 2:3 were equally attractive to males. DS females only produced one active compound, (Z)-7-decenyl acetate (V), and DS is the first Plusiinae species identified as using only the ω3-compound and none of ω5-compounds, such as II and III, which are common components of Plusiinae pheromones. Using previously published chemical and biosynthetic data, together with the finding from this study, we propose a classification of the Plusiinae sex pheromones.     

First Identification of a Putative Sex Pheromone in a Praying Mantid

Praying mantids are models for a wide variety of behavioral, physiological, and ecological studies, and sex pheromones have been assumed to be important components of their biology. However, no mantid pheromone has ever been identified. We collected volatiles emitted by females of the mantid, Sphodromantis lineola, via solid phase microextraction (SPME). Mass spectral analysis revealed the collected volatiles to be a mixture of pentadecanal and tetradecanal. We prepared a synthetic mixture of these compounds, and found that males were both attracted to this mixture and stimulated to exhibit typical precopulatory behavior. We then examined male antennae with scanning electron microscopy, and confirmed the presence of porous antennal sensilla typical of insect pheromone receptors, i.e., that male mantids are equipped with the appropriate morphological apparatus to receive volatile chemical signals. Pheromones, in conjunction with visual and tactile cues, are thus an important feature of the reproductive biology of this, and undoubtedly other species of mantids. In addition to adding a crucial aspect of behavioral biology to our knowledge of this group, identification and synthesis of mantid pheromones may be a first step in attracting and aggregating these generalist predators for use in pest control.     

Technique for injecting intact glands for analysis of sex pheromones of Lepidoptera by capillary gas chromatography

The structure elucidation of sex pheromones of Lepidoptera by a solid-sample injection technique in conjunction with capillary gas chromatography is described. The applicability of this method in GC and GC-MS modes was demonstrated by reanalyzing the sex attractants of females ofOstrinia nubilalis andBombyx mori. The pheromone complex ofMamestra brassicae was reinvestigated and (Z)-9-hexadecenyl acetate and (Z)-11-hexadecenol were found in addition to already known pheromone components of this species. By using the solid-sample injection, the exact site of pheromone release could be determined inM. brassicae.Pheromones 52. Pheromones, 51: Bestmann, H.J., and Schmidt, M. 1985.Tetrahedron Lett 26:6171–6174.     

Insect sex pheromones: Evaporation rates of alcohols and acetates from natural rubber septa

The half-lives (t _1/2) of alcohol sex pheromones, 1-alkanols, acetate sex pheromones, and an epoxide (disparlure) were determined on natural rubber septa. Thet _1/2 values for the homologous alcohols from decanol to heptadecanol increased regularly from 2.2 to 1117 days, but thet _1/2 of octadecanol was 609 days. Thet _1/2 values of (Z)7-, (E)7-, and (Z)9-tetradecen-1-ol acetates were 154, 168, and 199 days, respectively, whereas those of five other tested 14-carbon acetates ranged from 310 to 350 days. The dependence oft _1/2 values on chain length and double-bond position is consistent with the hypothesis that molecular size is an important variable affectingt _1/2 values. Also, in accordance with the hypothesis, when aZ-alkenyl compound has a much shortert _1/2 than the corresponding saturated compound, thet _1/2 values of theZ compound and itsE isomer may be quite different. Thus, (E)-9-tetradecen-l-ol acetate had at _1/2 of 331 days. Thet _1/2 of disparlure was 180 days. The effect of thecis-7,8 epoxide group is apparently similar to that of the olefin group in lowering thet _1/2 below the value that would be expected solely on the basis of chain length.This paper reports the results of research only. Mention of a commercial product in this paper does not constitute a recommendation by the U.S. Department of Agriculture.     

(Z)-9-tetradecen-1-ol acetate

(Z)-9-Tetradecen-1-ol acetate [(Z)-9-TDA], identified originally as the sex pheromone of the fall armyworm,Spodoptera frugiperda (J.E. Smith), acted as a secondary sex pheromone when it was tested in sticky traps in field tests. Low-level synergism was obtained when 2 and 10% quantities of (Z)-9-TDA were added to 100 g of (Z)-9-dodecen-1-ol acetate, which is now considered the primary sex pheromone.Lepidoptera: Noctuidae.In cooperation with the University of Georgia College of Agriculture Experiment Stations, Coastal Plain Station, Tifton, Georgia 31794.Mention of a proprietary product does not constitute endorsement by the USDA.     

Sex Pheromones of the American Cockroach,Periplaneta americana

Two sex pheromones, periplanone A and periplanone B were isolated from the American cockroach Periplaneta americana. The technique is described for collecting periplanone B from the alimentary tracts of virgin females. Periplanone A was extracted from the excreta of the insects. Mass spectral analysis of the pheromones and related compounds were performed and the results are reported here. Evidence is presented suggesting that periplanone A is in fact a degradation product of periplanone B. A reaction scheme is considered for the pathway: periplanone B → periplanone A → (stable, but inactive) PA 22–VII.     

Evidence for presence and nature of female sex pheromone ofBrithys crini fabricius (Lepidoptera: Noctuidae)

The existence of a female sex pheromone of the noctuid mothBrithys crini Fabricius was confirmed in both laboratory bioassay and field tests. Crude extracts and airborne volatiles from females were analyzed by gas chromatography and mass spectrometry and the data compared with authentic compounds. The primary sex pheromonal compound was Z11-16: Ald. Scanning electron microscopy showed that the external surface of the sex pheromone gland was covered with folds that might increase the sex pheromone evaporation area.     

Synthesis and Chemical Characterization of Hydrocarbons with a 6,9,11-, 3,6,9,11-, or 1,3,6,9-Polyene System,Pheromone Candidates in Lepidoptera

Lepidopteran Type II sex pheromones are mainly composed of 6,9-dienes, 3,6,9-trienes, and their epoxy derivatives, which are biosynthesized from linoleic and linolenic acids by the species in some families of higher Lepidoptera. To investigate further structural modifications on this theme, we synthesized polyunsaturated hydrocarbons with a C(17)-C(21) chain, which included an extra double bond. Using the Wittig reaction, (Z,Z,E)-6,9,11-trienes and (Z,Z,Z,E)-3,6,9,11-tetraenes were synthesized from (E)-2-alkenals with appropriate carbon chains, and (Z,Z,Z)-1,3,6,9-tetraenes were synthesized from 3-hexyn-1,6-diol. The gas chromatography-mass spectrometry (GC-MS) analysis of each synthetic polyene, whose chemical structure was confirmed by (1)H NMR and (13)C NMR, revealed some characteristic fragment ions reflecting the positions of the double bonds, i.e., m/z 79, 110, 163, and M-85 of the 6,9,11-trienes, m/z 79, 108, and M-82 of the 3,6,9,11-tetraenes, and m/z 79, 91, 106, and M-54 of the 1,3,6,9-tetraenes. Because the determination of the unsaturated positions is difficult to accomplish by chemical derivatization with a limited amount of natural pheromones, these diagnostic ions found in authentic samples would help identify the hydrocarbons in a pheromone extract. Furthermore, we carried out field screening tests of these polyenes in forests in Japan, and documented the attraction of four geometrid species in Tokyo and one noctuid species in the Iriomote Islands.     

Interactions Between Host-plant Volatiles and the Sex Pheromones of the Bird Cherry-oat Aphid, <Emphasis Type="Italic">Rhopalosiphum padi</Emphasis> and the Damson-hop Aphid, <Emphasis Type="Italic">Phorodon humuli</Emphasis>

The bird cherry-oat aphid, Rhopalosiphum padi (L.), and the damson-hop aphid, Phorodon humuli (Schrank), migrate at the same time of year and colonize closely related Prunus spp. as primary hosts, but utilize (1R,4aS,7S,7aR)-nepetalactol and (1RS,4aR,7S,7aS)-nepetalactol, respectively, as sex pheromones. Interactions between these sex pheromones and benzaldehyde and methyl salicylate, plant volatiles common to primary hosts of both species, were investigated to assess whether they confer reproductive isolation between these species. Female autumn migrants (gynoparae) and males of these two species were caught in the field with water traps baited with their respective sex pheromones. Rhopalosiphum padi gynoparae and males also responded positively to benzaldehyde. Release of either benzaldehyde or methyl salicylate with the conspecific sex pheromone increased catches of both species of aphid. However, releasing both plant volatiles with the sex pheromone of R. padi increased catches of gynoparae and males, but reduced those with the sex pheromone of P. humuli. These results support the hypothesis that specific plant volatiles synergize responses of autumn migrating aphids to their sex pheromone. Because these interactions are species-specific, they may be important in allowing males to discriminate between conspecific sexual females (oviparae) and those of other aphid species.     

Sex pheromone of the San Jose scale

The sex pheromone of the San Jose scale,Quadraspidiotus perniciosus (Comstock), was isolated from airborne collections on Porapak Q. Two components, present in approximately equal amounts, were identified as (Z)-3,7-dimethyl-2,7-octadien-1-yl propanoate and 3-methylene-7-methyl-7-octen-1-yl propanoate. Greenhouse bioassays and field tests have shown that the compounds are independently attractive to male San Jose scale. These structures are compared with those of other known scale pheromones.