Sex Pheromone Composition Research Articles

Host strain specific sex pheromone variation in Spodoptera frugiperda.

BackgroundThe fall armyworm Spodoptera frugiperda (Lepidoptera; Noctuidae) consists of two distinct strains with different host plant preferences for corn and rice. To assess whether pheromonal-mediated behavioral isolation accompanies the habitat isolation on different host plants, we compared the sex pheromone composition among females of the two strains. Pheromone glands were extracted with or without injection of pheromone biosynthesis activating neuropeptide (PBAN). To assess the mode of inheritance of this variation, we also analyzed the pheromone composition of F1 hybrid females.ResultsRelative to intra-strain variation, the pheromone composition of the two strains differed significantly. Corn strain females contained significantly more of the second most abundant pheromone compound Z11-16:Ac (m), and significantly less of most other compounds, than rice strain females. When females were injected with PBAN before their glands were extracted, the differences between the strains were less pronounced but still statistically significant. The pheromone composition of hybrid females showed a maternal inheritance of the major component Z9-14:Ac (M) as well as of Z11-16:Ac (m). Most other compounds showed an inheritance indicating genetic dominance of the corn strain. The within-strain phenotypic correlations among the various components were consistent with their hypothesized biosynthetic pathway, and between-strain differences in the correlation structure suggested candidate genes that may explain the pheromone differences between the two strains. These include Δ9- and Δ11 desaturases, and possibly also a Δ7-desaturase, although the latter has not been identified in insects so far.ConclusionThe two host strains of S. frugiperda produce systematically differing female sex pheromone blends. Previously-documented geographic variation in the sexual communication of this species did not take strain identity into account, and thus may be partly explained by different strain occurrence in different regions. The finding of pheromone differences reinforces the possibility of incipient reproductive isolation among these strains, previously shown to differ in the timing of nocturnal mating activity and host plant use. Finding the genetic basis of the pheromone differences, as well as these other biological traits, will help to elucidate the role of premating isolation in the continuing differentiation of these two strains that may eventually lead to speciation.

The odor of origin: kinship and geographical distance are reflected in the marking pheromone of male beewolves (Philanthus triangulum F., Hymenoptera, Crabronidae)

BackgroundPheromones play an important role for mate finding and courtship in many insects. In species where males are the signaling sex, females are expected to choose among potential mates with regard to the emitter's quality and/or genetic compatibility. One important aspect is the balance between negative and positive effects of in- vs. outbreeding. In the present study, we aimed to assess the potential of the territory marking pheromone of European beewolves as an indicator for genetic compatibility in the context of female choice.ResultsWe analyzed the sex pheromone composition of male European beewolves (Philanthus triangulum F., Hymenoptera, Crabronidae) from eight different locations across Central Europe (six in Germany, one in England, and one in Italy). The pheromone constitutes a complex blend of various long-chain hydrocarbons (alkanes, alkenes, alcohols, ketones, and a carbon acid). We demonstrate that pheromone composition differs significantly among distant populations (regional scale), among subpopulations (local scale) and between families within subpopulations. The differences in the pheromone blend are positively correlated with geographical distances as might be expected according to an isolation-by-distance model. On a local scale, family membership has a larger effect on pheromone composition than subpopulation affiliation, while the reverse is true for the regional scale.ConclusionOur results show that male pheromones can contain information on both kinship and geographical origin that may be used by females to choose adaptively among potential mates on the basis of their genetic distance.

Variation in sex pheromone composition in large fruit-tree tortrix Archips podana Scop. (Lepidoptera: Tortricidae)

Variation in sex pheromone composition was studied in large fruit-tree tortrix. The pheromone contained cis-11-tetradecenyl acetate and trans-11-tetradecenyl acetate as macrocomponents as well as microcomponents cis-11-tetradecenol and trans-11-tetradecenol with the prevalence of cis-11-tetradecenyl acetate and cis-11-tetradecenol. The pheromone composition depended in part on the genotype of the male parent. Inbreeding increased the proportion of trans-11-tetradecenyl acetate and trans-11-tetradecenol.

Isolation, Identification, Synthesis, and Field Evaluation of the Sex Pheromone of the Brazilian Population of Spodoptera frugiperda

Several studies have shown intraspecific geographical variation in the composition of sex pheromones. Pheromone lures from North America and Europe were not effective against the fall armyworm Spodoptera frugiperda (Smith, 1797) (Lepidoptera: Noctuidae) in Brazil, so we examined the composition of the sex pheromone produced by females from Brazilian populations. Virgin female gland extracts contained (Z)-7-dodecenyl acetate (Z7-12:Ac), (E)-7-dodecenyl acetate (E7-12:Ac), dodecyl acetate, (Z)-9-dodecenyl acetate, (Z)-9-tetradecenyl acetate (Z9-14:Ac), (Z)-10-tetradecenyl acetate, tetradecyl acetate/(Z)-11-tetradecenyl acetate (Z11-16:Ac), and (Z)-11-hexadecenyl acetate. The relative proportions of each acetate were 0.8:1.2:0.6:traces:82.8:0.3:1.5:12.9, respectively. This is the first time that E7-12:Ac has been reported from the pheromone gland of S. frugiperda. Only three compounds, Z9-14:Ac, Z7-12:Ac, and E7-12:Ac, elicited antennal responses, and there were no differences in catch between traps baited with either Z7-12:Ac + Z9-14:Ac or Z7-12:Ac + Z9-14:Ac + Z11-16:Ac blends. However, the Z7-12:Ac + Z9-14:Ac + E7-12:Ac blend was significantly better than Z7-12:Ac + Z9-14:Ac, indicating that E7-12:Ac is an active component in the sex pheromone of the Brazilian populations of S. frugiperda.

Identification of Queen Sex Pheromone Components of the Bumblebee Bombus terrestris

We investigated the origin and chemical composition of the queen sex pheromone of the primitively eusocial bumblebee, Bombus terrestris (Apidae). Physiologically and behaviorally active compounds were identified by coupled gas chromatography electro-antennography (GC-EAD), gas chromatography-mass spectrometry (GC-MS), and laboratory behavioral tests. In the behavioral assays, virgin queens frozen previously at -20 degrees C were highly attractive to males. Dummies impregnated with surface and cephalic extracts obtained from virgin queens that had been frozen at -50 degrees C were more attractive to males than odorless dummies. Male mating behavior was stimulated by components of cephalic secretions that are smeared onto the cuticle surface by the queen. Overall, 21 compounds present in surface and cephalic extracts evoked electroantennographic responses in male antennae. These included saturated and unsaturated fatty acids, ethyl- and methyl esters of the fatty acids, heptacosene, 2-nonanone, and geranyl geraniol. A blend of synthetic versions of these compounds elicited typical male mating behavior. Since solvent-impregnated dummies were approached by the males, but did not release copulatory behavior, visual cues may be important in the initial step of stimulating male mating behavior. Close-range olfactory signals are more important for releasing male mating behavior as well as for species recognition. In further behavioral assays, the attractiveness of a frozen virgin queen decreased as the storage time at -20 degrees C increased from 2 hr to 1 d. Therefore, the chemical composition of the sex pheromone may change during freezing as behaviorally active compounds may decompose.

Comparative study of sex pheromone composition and biosynthesis in Helicoverpa armigera, H. assulta and their hybrid

Two Helicoverpa species, H. armigera and H. assulta use ( Z)-11-hexadecenal and ( Z)-9-hexadecenal as their sex attractant pheromone components but in opposite ratios. Since both female and male interspecific hybrids produced by female H. assulta and male H. armigera have been obtained in our laboratory, we can make a comparative study of sex pheromone composition and biosynthesis in the two species and their hybrid. With GC and GC–MS analyses using single gland extracts, the ratio of ( Z)-9-hexadecenal to ( Z)-11-hexadecenal was determined as 2.1:100 in H. armigera, and 1739:100 in H. assulta. The hybrid has a ratio of 4.0: 100, which is closer to that of H. armigera, but significantly different from H. armigera. We investigated pheromone biosynthesis with labeling experiments, using various fatty acid precursors in H. armigera, H. assulta and the hybrid. In H. armigera, ( Z)-11-hexadecenal is produced by Δ11 desaturation of palmitic acid, followed by reduction and terminal oxidation; ( Z)-9-hexadecenal results from Δ11 desaturation of stearic acid, followed by one cycle of chain shortening, reduction and terminal oxidation. Δ11 desaturase is the unique desaturase for the production of the two pheromone components. In our Chinese strain of H. assulta, palmitic acid is used as the substrate to form both the major pheromone component, ( Z)-9-hexadecenal and the minor one, ( Z)-11-hexadecenal. Our data suggest that Δ9 desaturase is the major desaturase, and Δ11 desaturase is responsible for the minor component in H. assulta, which is consistent with previous work. However, the weak chain shortening acting on ( Z)-9 and ( Z)-11-octadecenoic acid, which is present in the pheromone glands, does occur in this species to produce ( Z)-7 and ( Z)-9-hexadecenoic acid. In the hybrid, the major pheromone component, ( Z)-11-hexadecenal is produced by Δ11 desaturation of palmitic acid, followed by reduction and terminal oxidation. The direct fatty acid precursor of the minor component, ( Z)-9-hexadecenoic acid is mainly produced by Δ9 desaturation of palmitic acid, but also by Δ11 desaturation of stearic acid and one cycle of chain shortening. The greater relative amounts of ( Z)-9-hexadecenal in the hybrid are due to the fact that both palmitic and stearic acids are used as substrates, whereas only stearic acid is used as substrate in H. armigera. The evolutionary relationships between the desaturases in several Helicoverpa species are also discussed in this paper.

Insect semiochemical research in Korea: Overview and prospects

Rapid progress has been made in research on insect pheromones and other semiochemicals in Korea during the last two decades. Sex pheromone compositions have been identified in several major orchard and other horticultural moth pest species and some other species in Korea, such as Helicoverpa assulta, Grapholita molesta, Carposina sasakii, Adoxophyes orana, Lyonetia prunifoliella, Phyllonorycter ringoniella, Dichocrocis punctiferalis, Ostrinia furnacalis and Peridroma saucia. Some of these identified sex pheromones have already been successfully incorporated into IPM systems, and are now being used as direct and indirect pest control means in Korea. Korean populations of many of these species showed significant differences in pheromone compositions from those reported in the neighboring countries of Japan and China, suggesting that such interpopulational pheromone polymorphism is more common across the insect world than previously thought. Sex pheromone compositions were also identified in some aphid species in Korea such as Aphis spiraecola and Tuberocephalus momonis, and it was soon found that the aphid sex pheromone components were highly attractive to their predator lacewings. The presence of kairomones responsible for attracting egg parasitoids was shown in a pheromone component, hot pepper odor and male scale factor for H. assulta, and in male accessory glands for Lymantria dispar. Studies on the regulation of pheromone biosynthesis and release were carried out simultaneously in some species in Korea, resulting in the characterization of PBAN (pheromone biosynthesis activating neuropeptide) in H. assulta and Adoxophyes sp. A semiochemical research system has been firmly established in Korea through these studies. In some areas, successful monitoring and mating disruption technology have been effectively transferred from researchers to the end users in Korea, which will soon be expanded to wider areas. Continuous attempts to identify and use semiochemicals as well as wider applications of semiochemicals in pest control are expected in Korea in the coming years. Since Korean research on semiochemicals does not cover vast areas due to limited resources, focused research and practical application will be needed for selected target insect species.

Identification of polyenic hydrocarbons from the northern winter moth, Operophtera fagata , and development of a species specific lure for pheromone traps

In order to elucidate the composition of the female sex pheromone of the northern (beech) winter moth, Operophtera fagata Scharf. (Lepidoptera: Geometridae), ovipositor extracts of unmated, calling females were analysed by gas chromatography with simultaneous electroantennographic and flame ionization detection (GC-EAD/FID). Male antennal responses indicated three active components, two of which had distinct matching peaks in the FID trace. Using coupled gas chromatography- mass spectrometry (GC-MS), these two compounds were identified as (9Z)-nonadecene (9Z-19:Hy), and (6Z,9Z)-nonadecadiene (6Z9Z-19:Hy), respectively. The third component, present in very small amounts only, was identified as (1,3Z,6Z,9Z)-nonadecatetraene (1,3Z6Z9Z-19:Hy), known as the sex pheromone of the common winter moth, O. brumata. Field tests revealed that traps baited with 6Z9Z-19:Hy and 1,3Z6Z9Z-19:Hy caugth large numbers of male O. fagata. Both compounds were found to be essential for attraction of O. fagata. In addition, the diene prevented captures of co-occurring O. brumata. In contrast, 9Z-19:Hy neither influenced the attractiveness of the two-component mixture towards O. fagata nor contributed to bait specificity. A binary mixture of 6Z9Z-19:Hy and 1,3Z6Z9Z-19:Hy in a ratio of 10:1, applied to pieces of rubber tubing, constituted a highly attractive and species-specific bait for O. fagata, which can be used for monitoring of the flight of this defoliator pest of deciduous forests.

Host-Plant Specialization in Pheromone Strains of the European Corn Borer Ostrinia nubilalis in France

European corn borer (ECB) feeding on maize (Zea mais), mugwort (Artemisia vulgaris), and hop (Humulus lupulus) are genetically different in France and referred to as host-plant races. Here, we investigated sex pheromone composition as a possible trait linked to the host plant. ECB host races were sampled from 13 different sites in France. GC-MS analysis of female pheromone showed that 175 out of 176 maize females belonged to the Z type with one hybrid. In contrast, mugwort and hop females belonged almost exclusively to the E type. No Z females were found on these plants and only 2 females out of 169 were hybrids. In the three sites of sympatry, the hybrid proportion was far from Hardy-Weinberg expectations. Wind tunnel experiments showed that 76-79% of maize males from three populations were attracted by Z females, whereas neither mugwort nor hop males were. Mugwort males from Toussus-le-Noble were attracted by E females originating from an American maize strain. These data showed that maize, mugwort, and hop host races of O. nubilalis differ not only in their host plant but also in the sex pheromone they use. Because mugwort and hop are putative ancestral host plants, these results are discussed from the point of view of evolutionary scenarios for the emergence of Z and E strains.

Optimal Sex Pheromone Composition for Monitoring Spodoptera exigua (Lepidoptera: Noctuidae) in Korea

The sex pheromone composition for the Korean population of the beet armyworm, Spodoptera exigua (Hübner) (Lepidoptera: Noctuidae) was determined from the abdominal tip extract of virgin females during her calling period. Gas chromatography of the extracts revealed 3 components; Z,E-9, 12-tetradecadienyl acetate ( Z,E-9,12–14: Ac), Z9-tetradecen-1-ol ( Z9–14: OH), and Z9-tetradecenyl acetate ( Z9–14: Ac). In electroantennogram analyses to males, a main component, Z,E-9,12–14: Ac, evoked significantly higher response than did the other two components. Although male moths were broadly attracted to lures, composed of Z,E-9,12–14: Ac and Z9–14: OH with ratios from 9:1 to 1:9, in Andong and Seosan field areas, the 7:3 blend was found to be the most effective. The optimal height of trap location was 1.5 m above ground. Three minor sex pheromone components including Z9-hexadecenyl acetate ( Z9–16: Ac), Z11- tetradecenyl acetate ( Z11–14: Ac), and Z9-tetradecenyl acetate ( Z9–14: Ac) were reported before from local populations. But, in this study, only Z11–16: Ac showed significant synergistic effect on enhancing the attractiveness of the major component blends at ratios of 7:3:1 and 7:3:5 of Z,E-9,12–14: Ac, Z9–14: OH, and Z11–16: Ac.

(Z)-7-DODECENYL ACETATE: A SUPERNORMAL STIMULUS OF Trichoplusia ni (HÜBNER) [LEPIDOPTERA: NOCTUIDAE] SEX PHEROMONE BEHAVIOR

Males discriminate between the single most important individual component of the sex pheromone of the female cabbage looper, Trichoplusia ni (Hübner), (Z)-7-dodecenyl acetate (Z7-12:Ac), and a mixture containing Z7-12:Ac and the other five putative components. The manifestation of discrimination is not an enhancement of captures by the mixture; rather, it is a reduction of captures in a paired trap baited with Z7-12:Ac by itself. Previous experiments showed that either or both of (Z)-7-tetradecenyl acetate (Z7-14:Ac) and (Z)-9-tetradecenyl acetate (Z9-14:Ac) were responsible for this discrimination. This report provides evidence that Z7-14:Ac is more active than Z9-14:Ac, which appears to have no demonstrable effect on behavior. The results are discussed with reference to the behavior that is effected by the above three components, the composition of the native sex pheromone, and whether or not Z7-12:Ac might be a supernormal releaser of behavior.

Heritable variation of sex pheromone composition and the potential for evolution of resistance to pheromone-based control of the Indian meal moth, Plodia interpunctella.

The short-term evolutionary effect of pheromone-based mating disruption on the mating ability of the Indian meal moth, Plodia interpunctella, was investigated. Three independent selection lines were established, and the mating ability of moths in plastic tents treated with high doses of pheromone and in control tents was compared for two consecutive generations. In addition, the heritability of the sex pheromone blend, measured as the ratio of two major pheromone components (Z,E)-9,12-tetradecadienyl acetate and (Z,E)-9,12-tetradecadienol, was estimated. Based on a mother-daughter regression analysis including 21 families, the heritability of the pheromone blend was 0.65 +/- 0.14, indicating a potential for evolutionary change of the character. However, no increase in mating ability of females in pheromone-treated tents or alteration of the pheromone blend was observed in any selection line when compared with control lines, indicating no or weak selection on the pheromone blend as well as other traits influencing mating ability of this species under the created mating disruption conditions. Factors contributing to the lack of selection effects are discussed.

Identification of sex pheromone composition of click beetle Agriotes brevis candeze.

Geranyl butyrate (GB) and (E, E)-farnesyl butyrate (FB) were identified in the pheromone gland extract of females of the click beetle, Agriotes brevis (Candeze) (Coleoptera: Elateridae) as the major sex pheromone components. Polyethylene vial dispensers containing 20-200 mg of a 1:1 mixture caught high numbers of beetles. Captures did not decrease even after 73 days of field exposure of dispensers. At sites where both Agriotes sputator L. and A. brevis were present, the above baits were selectively catching only A. brevis, despite the fact that GB is also the main pheromone component of A. sputator, suggesting that FB has a role in reproductive isolation. In the early part of the season, traps into which the insects could both crawl and fly captured more A. brevis than designs where the insects could only fly in. Trap design was not important later in the season. This indicates the need for future development of a trap suitable for use throughout the whole season.

Sex Pheromone Composition and Male Trapping of The Oriental Fruit Moth, Grapholita molesta (Lepidoptera: Tortricidae) in Korea

Sex pheromone composition was analyzed for the oriental fruit moth ( Grapholita molesta), and field trapping studies were also conducted to develop monitoring system with its sex pheromone in Korea. The calling and mating behavior of G. molesta were seen maximally 2 to 1 hr before lights-off and these behavior ceased after lights-off. Analysis of abdominal tip extracts from virgin females of G. molesta revealed 4 compounds, Z8-dodecenyl acetate ( Z8-12: Ac), E8-dodecenyl acetate ( E8–12: Ac), Z8-dodecenol ( Z8–12: OH) and dodecanol (12: OH). In the field trappings, the best capturing activity for G. molesta was observed with the 95:5:1 blend of Z8–12: Ac, E8–12: Ac and Z8–12: OH but 12: OH showed no synergic effect. The most effective amount of sex pheromone blend was 0.5 mg for a lure.

Sex Pheromone Composition and Male Trapping of the Peach Fruit Moth, Carposina sasakii (Matsumura) (Lepidoptera: Carposinidae) in Korea

Sex pheromone composition, mating behavior, and field trapping were analyzed for the peach fruit moth, Carposina sasakii(Matsumura) to develop a monitoring system with its sex pheromone. The upwind flying response of males to female was the most frequent at 4th to 5th hr after lights-off. The highest mating rate was seen at 5th hr after lights-off. The extract of female abdominal tip was analyzed with gas chromatography and proved to have two compounds, ( Z)-7-eicosen-11-one and ( Z)-7-nonadecen-11-one. In field-trapping, however, a lure containing ( Z)-7-eicosen-11-one only showed the highest attractivity.

Geographical variation in female sex pheromones of the rice leaffolder moth, Cnaphalocrocis medinalis: identification of pheromone components in Japan

AbstractSex pheromone components of the Japanese rice leaffolder moth, Cnaphalocrocis medinalis Guenée (Lepidoptera: Pyralidae) were identified from ovipositor extracts of virgin females as (Z)‐11‐octadecenal, (Z)‐13‐octadecenal, (Z)‐11‐octadecen‐1‐ol and (Z)‐13‐octadecen‐1‐ol at a ratio of 11:100:24:36 by GC‐EAD, GC, GC‐MS. The total amount was estimated to be ca.0.9 ng/female. Field bioassays in Kagoshima, Japan, showed that the two aldehydes are essential for male attraction and the alcohols may have a synergistic effect on the aldehydes. A rubber septum containing 0.9 mg of the four components at the natural ratio was shown to be an effective lure for monitoring this pest in Japan. The above four components are quite different from the sex pheromone components reported previously for the same species of either Philippine or Indian origin; components were shown to be (Z)‐11‐hexadecenyl acetate and (Z)‐13‐octadecenyl acetate at a ratio of 98:2 in the Philippine blend and 1:10 in the Indian blend. Furthermore, in the field tests in Japan, neither the Philippine blend nor the Indian blend showed any attractive activity, while the Japanese blend attracted significant numbers of male moths. These results suggest that there are remarkable geographical variations in the sex pheromone composition of this species or there are several distinct species using different sex pheromone blends.

Dogwood Borer (Lepidoptera: Sesiidae) Flight Activity and an Attempt to Control Damage in ‘Gala’ Apples Using Mating Disruption

‘Gala’ apple trees had a high incidence of burr knots (adventitious root primordia) produced on the trunk. Dogwood borer, Synanthedon scitula (Harris), infested many of these growths. Mating disruption using a sex attractant for dogwood borer, (Z,Z)-3,13-ODDA, did not control dogwood borer injury. In addition to other variables inherent to mating disruption (dispenser release and application rate, pest density, environmental factors), one potential reason for the failure was an inadequate conception of the dogwood borer sex pheromone composition. Therefore, the composition of dogwood borer pheromone should be reexamined. Traps baited with lilac borer, Podosesia syringae (Harris), lures were more sensitive for capturing dogwood borer males than traps baited with lures for dogwood borer. This is difficult to explain because the lures purportedly are identical. This difference in trap response further supports the need for reexamination of the pheromone blend compositions for each species. A complex of seven sesiids was attracted to both dogwood borer and lilac borer traps; captures of all were almost entirely eliminated by permeation with (Z,Z)-3,13-ODDA. There was a bimodal pattern of adult activity, with an early peak trap capture in May–June, and a later peak in July–August. The hypothesis of apple producing a later period of dogwood borer emergence than from dogwood was supported. This will complicate control in ‘Gala’ using current borer insecticides (e.g., chlorpyrifos, endosulfan) because of the proximity of harvest in this early-maturing variety with the ovipositional period of dogwood borer.

Variation in Sex Pheromone Composition of a Few Selected Lepidopteran Species

Composition of insect sex pheromone is not always constant for any particular species. It may be different depending on the geographical area in the distribution of a species, as can be seen in the case of the European corn borer moth, Ostrinia nubilalis (Pyralidae). During the course of examining sex pheromone compositions of several lepidopteran species damaging agricultural and horticultural crops in South Korea, some subtle or apparent differences were noticed in sex pheromone compositions of Korean population belonging to those same species distributed in her neighboring countries. The oriental tobacco budworm moth, Helicoverpa assulta (Noctuidae), in Korea prefers the blend of 100 : 5 between ( Z)-9-hexadecenal and ( Z)-11-hexadecenal, while Thailand population responds best to 100 : 13 and Chinese population to wider blends from 100 : 2 to 100 : 20. Among lepidopteran insect pests on apples and apple tree leaves, the oriental fruit moth, Grapholita molesta (Tortricidae), showed almost no difference from one region to another. Korean population responded best to the blend of 100 : 5, with other populations to 100 : 6∼100 : 9 between ( Z)-8-dodecen-1-ol acetate and ( E)-8-dodecen-1-ol acetate. On the other hand, the peach fruit moth, Carposina sasakii (C. niponensis) (Carposinidae), males were attracted best to a single component, ( Z)-7-eicosen-11-one in the case of Korean population, in contrast to Japanese population which was shown to be preferentially attracted to the mixture of the ( Z)-7-eicosen-11-one and ( Z)-7-nonadecen-11-one at the ratio of 100 : 5. The yellow peach moth, Dichocrocis punctiferalis (Pyralidae), seems to consist of two different populations in the northeastern Asia region, with one group responding to the blend of 100 : 8∼100 : 11 between ( E)-10-hexadecenal and ( Z)-10-hexadecenal and the other to that of 100 : 43. The first group was found in Japan and China and the second in Korea and also China. Korean population of the apple leaf miner, Phyllonorycter ringoniella (Gracillariidae), was best attracted to the blend of 100 : 150 between ( Z)-10-tetradecen-1-ol acetate and ( E, Z)-4,10-tetradecen-1-ol acetate, while Japanese and Chinese populations to the blends of 100 : 10∼30 and 100 : 43∼67, respectively. Furthermore, Korean Adoxophyes (Tortricidae) seemed to be a totally different species from Japanese Adoxophyes sp., or Adoxophyes orana fasciata, when viewed in terms of their pheromone composition.

Male dominant/subordinate relationships, cuticular profiles and sex pheromone in Nauphoeta cinerea (Dictyoptera, Blaberidae)

In the cockroach Nauphoeta cinerea, male-male aggressive interactions result in dominant-subordinate relationships. Once dominance relationships are established, a male can recognize the status of another individual, likely through chemical cues. The aim of this study was to determine the effect of these male-male interactions on cuticular chemical profiles and on the relative composition of the male sex pheromone. The results of chemical analyses of males reared in pairs for 30 days clearly showed significant differences in both cuticular profiles and sex pheromone of dominant and subordinate individuals. The possible role of these compounds as recognition cues was discussed.

Electroantennogram, wind tunnel and field responses of male Mediterranean corn borer, Sesamia nonagrioides, to several blends of its sex pheromone components

AbstractThe electrophysiological and behavioural responses of male Sesamia nonagrioides Lefèbvre (Lepidoptera: Noctuidae) to several synthetic blends of its sex pheromone components were investigated. Electroantennogram (EAG) recordings showed the greatest response to a 77:8:10:5 blend of the four compounds found in the female glands: (Z)‐11‐hexadecen‐1‐yl acetate, (Z)‐11‐hexadecen‐1‐ol, (Z)‐11‐hexadecenal and dodecyl acetate. A logistic equation was fitted to the dose‐response data and differences in relative EAG responses were analysed by deriving five parameters of this equation. Flight responses of males were also evaluated in a wind tunnel where the proposed blend (77:8:10:5) also elicited the best response. Field tests confirmed the laboratory findings as the 77:8:10:5 blend captured more S. nonagrioides males than other pheromone mixtures and showed more selectivity for male S. nonagrioides over other noctuid species, Discestra trifolii Rottenberg and Lacanobia oleracea L., but not for Mythimna unipuncta Haworth, a species with a sex pheromone composition almost identical to that of S. nonagrioides.