Sex pheromone of the butterbur borer, Ostrinia zaguliaevi

The sex pheromone blend of the butterbur borer, Ostrinia zaguliaevi (Lepidoptera: Pyralidae) was analyzed by means of gas chromatography-electroantennographic detection (GC-EAD), GC-mass spectrometry and a series of wind-tunnel bioassays. Four EAD-active compounds were detected in the female sex pheromone gland extract, and these were identified as tetradecyl acetate (14:OAc), (Z)-9-tetradecenyl acetate (Z9-14:OAc), (E)-11-tetradecenyl acetate (E11-14:OAc) and (Z)-11-tetradecenyl acetate (Z11-14:OAc). The average amounts ± s.d. of the four compounds in a single sex pheromone gland were 7.9±3.7 ng, 10.1±3.2 ng, 1.1±0.5 ng and 11.6±5.1 ng, respectively. In a wind-tunnel bioassay, the ternary blend of Z9-, E11- and Z11-14:OAc at a ratio found in the sex pheromone gland (45:5:50) elicited the same behavioral responses from the males as did virgin females and pheromone gland extract. Removal of any single compound from the ternary blend significantly diminished the pheromonal activity, whereas addition of 14:OAc to the ternary blend had no effect on the males' behavioral responses. Therefore, it was concluded that the sex pheromone blend of O. zaguliaevi is composed of Z9-14:OAc, E11-14:OAc and Z11-14:OAc at a ratio of 45:5:50.     

Identification of the sex pheromone of Ostrinia palustralis

By means of gas chromatography with electroantennographic detection, gas chromatography-mass spectrometry and a series of bioassays, (E)-11-tetradecenyl acetate (E11-14:OAc) and (Z)-11-tetradecenyl acetate (Z11-14:OAc) at a ratio of 99:1 were identified as female sex pheromone components of Ostrinia palustralis. The average amounts of E11- 14:OAc and Z11-14:OAc in a single sex pheromone gland were 37.2±24.4 ng and 0.3±0.2 ng, respectively. In a wind-tunnel bioassay, the binary blend of E11- and Z11-14:OAc elicited the same male behavioral responses as did virgin females.     

Inter- and intraspecific activities of compounds derived from sex pheromone glands of currant borer, Synanthedon tipuliformis (Clerck) (Lepidoptera: Sesiidae)

Gas chromatography and mass spectrometry analyses of crude sex pheromone gland extracts revealed that virgin Synanthedon tipuliformis (Clerck), currant borer (Lepidoptera: Sesiidae) females, produced 6 compounds, structurally related to sex pheromone components of clearwing moths. By comparison of retention times and mass spectra of natural products with corresponding properties of synthetic standards, these compounds were identified as: (2E,13Z)-octadeca-2,13-dien-1-yl acetate (E2,Z13-18:OAc), (3E,13Z)-octadeca-3,13-dien-1-yl acetate (E3,Z13-18:OAc), (13Z)-octadec-13-en-1-yl acetate (Z13-18:OAc), (2E,13Z)-octadeca-2,13-dien-1-ol (E2,Z13-18:OH), (13Z)-octadec-13-en-1-ol (Z13-18:OH) and octadecan-1-ol (18:OH) in the ratio 100:0.7:2.7:3.2:traces:traces. The first 3 compounds were previously known to occur in the sex pheromone gland extracts of currant borers, while the last 3 chemicals are now reported for the first time. Trapping tests carried out in the black currant field revealed that E2,Z13-18:OAc, when tested separately, attracted S. tipuliformis males, while addition of E3,Z13-18:OAc to the main component increased the effectiveness of E2,Z13-18:OAc over seven times. The attractiveness of 6 component lures did not differ significantly from the one of the binary mixture, confirming that E2,Z13-18:OAc and E3,Z13-18:OAc in the ratio100:0.7 are essential sex pheromone components of S. tipuliformis. Trapping tests carried out at the dwelling place of Synanthedon scoliaeformis (Borkhausen) (Lepidoptera: Sesiidae) revealed that, in addition to intraspecific synergistic effect, E3,Z13-18:OAc increased the specificity of the pheromone signal of S. tipuliformis, acting by intraspecific mode as an attraction antagonist against S. scoliaeformis males. By this way, it ensured the specificity of the sex attraction signal of the currant borer. Consequently, both compounds E2,Z13-18:OAc and E3,Z13-18:OAc have to be present in pheromone formulations used for monitoring and/or control of S. tipuliformis to avoid effecting non-target species. Other compounds identified from the sex pheromone gland of S. tipuliformis did not show any significant interspecific activity for males of S. scoliaeformis, however, they provide a basis to achieve specificity of a pheromone signal of S. tipuliformis and could act as attraction antagonists against other clearwing moth species which, like S. tipuliformis, employ E2,Z13-18:OAc as their sex pheromone component.     

Sex pheromones of Phyllonorycter acerifoliella and Ph. heegerella and communication peculiarities in three species of leafmining moths

Females of the leaf miner moth Phyllonorycter acerifoliella (Z.) [=Ph. sylvella (Hw.)] and Ph. heegerella (Z.) (Lepidoptera: Gracillariidae: Lithocolletinae) release their sex pheromone at the beginning of photophase. The periodicity of the `calling' behaviour of Ph. acerifoliella females was established. Three compounds from calling virgin Ph. heegerella females were collected by the Solid Phase Micro Extraction (SPME) technique and identified as (Z)-8-tetradecenyl acetate (Z8-14:OAc), tetradecyl acetate (14:OAc) and (Z)-8-tetradecenol (Z8-14:OH) in the ratio (88±3):(2±0.6):(10±5) by capillary gas chromatography and mass spectrometry. Field trapping experiments demonstrated that the first two compounds are important for the attraction of conspecific males. Z8-14:OAc was found to be attractive when tested separately, while 14:OAc acted as synergist. The attractivity of the three component blend was reduced by 10% admixture of either (E)-10-dodecenyl acetate (E10-12:OAc) or (Z)-10-tetradecenyl acetate (Z10-14:OAc).Field tests of Z10-, Z8- and E10-14:OAc, identified from Ph. acerifoliella females, demonstrated that the first two compounds were essential for the attraction of conspecific males; so both are sex pheromone components. The attractivity of the three component blend of Z10- Z8- and E10-14:OAc was reduced by 10% admixture of (E)-10-dodecenol (E10-12:OH). The following four semiochemical compounds, Z8-14:OAc, Z8-14:OH, E10-14:OAc and 14:OAc, identified from phyllonoryctid females, as well as two sex attraction antagonists for Ph. acerifoliella and Ph. heegerella males, E10-12:OAc and Z10-14:OAc, are new for the family Gracillariidae. The results of field trapping experiments revealed mechanisms ensuring the specificity of the chemocommunication systems in Ph. acerifoliella, Ph. heegerella and Ph. ulmifoliella (Hb.) moths.     

Sex pheromone of the African armyworm <Emphasis Type="Italic">Spodoptera exempta</Emphasis> (Lepidoptera: Noctuidae): identification of components of the Okinawan population and formulation for population monitoring

In 2010, abrupt outbreaks of the African armyworm, Spodoptera exempta (Walker), occured on the Tarama, Iriomote and Kikai Islands in southwestern Japan. Analysis by gas chromatography-electroantennographic detection (GC-EAD) revealed two EAG-active compounds on male antenna in crude extract of virgin females. These compounds were identified as (9Z)-9-tetradecenyl acetate (Z9-14:Ac) and (9Z,12E)-9,12-tetradecadienyl acetate (Z9E12-14:Ac) in ca. 90:10 ratio by subsequent GC-MS analyses. (11Z)-11-Hexadecenyl acetate (Z11-16:Ac), which had previously been identified as a third component in the Kenyan population, was not detected. Binary blends of Z9-14:Ac and Z9E12-14:Ac at ratios between 99:1 and 90:10 showed a potent attractiveness in the field, superior to that of virgin females and comparable to that of the three-component formulation determined in Kenya. For the population survey, a 98:2 blend was used. In Tarama, only a few moths of S. exempta were captured with a light trap during the night when more than 600 males were captured with synthetic sex pheromone; more S. exempta captures with a light trap had been reported than with sex-pheromone traps in Kenya. This indicates that the Okinawan population has different properties from the Kenyan population in pheromone composition and behavioral response to light.     

Reidentification of pheromone composition of Sparganothis sulfureana (Clemens) and evidence of geographic variation in male responses from two US states

GC-EAD analyses of pheromone gland extracts of calling female Sparganothis sulfureana revealed at least 6 compounds that consistently elicited antennal responses from male antennae. In addition to the major pheromone compound, (E)-11-tetradecenyl acetate (E11–14:OAc), which was previously reported, the other compounds were found to be (E)-9-dodecenyl acetate (E9–12:OAc), (Z)-9-dodecenyl acetate (Z9–12:OAc), (Z)-9-tetradecenyl acetate (Z9–14:OAc), (Z)-11-tetradecenyl acetate (Z11–14:OAc), and (E)-11-tetradecenol (E11–14:OH). Tetradecyl acetate, hexadecyl acetate and hexadecenyl acetates were also present in the extracts, but elicited no EAG response from male antennae. Wind tunnel tests demonstrated that males from New Jersey responded equally well to a blend containing five pheromone components in relative to the pheromone glands of calling females. Different male-response profiles from field-trapping tests conducted in the states of Wisconsin and New Jersey were observed, respectively. Significantly higher numbers of male S. sulfureana were caught in New Jersey in traps baited with the binary blend of E11–14:OAc (30 μg) with 1% of Z11–14:OAc, but males from Wisconsin responded equally well to traps containing blends of E11–14:OAc with 0–10% of Z11–14:OAc. The addition of more than 10% of Z11–14:OAc to the primary pheromone compound reduced male captures significantly in both states. Male catches were doubled by adding E9–12:OAc and E11–14:OH to the most attractive binary blend in both states. The trapping test with caged live virgin female moths showed that males in Wisconsin preferred females from the local population than those from New Jersey. The differences in male responses observed may indicate the existence of pheromone polymorphism in this species.     

Evidence of olfactory antagonistic imposition as a facilitator of evolutionary shifts in pheromone blend usage in Ostrinia spp. (Lepidoptera: Crambidae)

Olfactory receptor neuron (ORN) response was measured to assess why some males ("rare males") of the Asian corn borer (ACB), Ostrinia furnacalis, have a broad behavioral response to fly upwind to both the ACB and the European corn borer (ECB), Ostrinia nubilalis, pheromone blends. We performed single-sensillum electrophysiological recordings on ACB males that had been behaviorally assessed for upwind flight response to the ACB blend [60:40 (Z)-12-tetradecenyl acetate (Z12-14:OAc) to (E)-12-tetradecenyl acetate (E12-14:OAc)], as well as to ECB (Z-strain) and ECB (E-strain) blends [3:97 and 99:1 (Z)-11-tetradecenyl acetate (Z11-14:OAc) to (E)-11-tetradecenyl acetate (E11-14:OAc)]. Sensilla from all types of males had large- and small-spike-sized ORNs responding strongly to Z12- or E12-14:OAc, but weakly to Z11- and E11-14:OAc. In the majority of males ("normal males") that flew upwind only to the ACB blend, Z11-14:OAc elicited responses in an intermediate spike-sized ORN associated with behavioral antagonism that is mainly tuned to (Z)-9-tetradecenyl acetate (Z9-14:OAc). In the rare-type ACB males that flew to both the ACB and ECB pheromone blends, Z11-14:OAc did not stimulate this ORN. Increased responsiveness to ancestral pheromone components by ORNs associated with behavioral antagonism could be instrumental in reproductive character displacement, or in reinforcement and reproductive isolation during speciation by helping to increase assortative mating between males and females in derived populations that use novel sex pheromone blends.     

Sex pheromone analysis and effective attraction of males of the cabbage webworm,Hellula undalis,inhabiting the Mekong Delta of Vietnam

Hellula undalis is a harmful insect pest of green mustard in the Mekong Delta of Vietnam. In order to establish a tool for a sustainable pest control program, the sex pheromone of H. undalis inhabiting the Mekong Delta was examined. GC-EAD and GC–MS analyses of pheromone gland extracts from the virgin females elucidated three new components, (Z)-11-tetradecenyl acetate (Z11-14:OAc), (Z)-11-hexadecenal (Z11-16:Ald), and (11E,13E)-11,13-hexadecadien-1-ol, in addition to the known pheromone component (11E,13E)-11,13-hexadecadienal (E11,E13-16:Ald). Double bond positions of the two monoenyl components were determined by GC–MS analysis of the pheromone extract treated with dimethyl disulfide. On the other hand, GC–MS analysis of the female body extract detected the unsaturated hydrocarbon (3Z,6Z,9Z)-3,6,9-tricosatriene (Z3,Z6,Z9-23:H). Field examinations of their synthetic compounds indicated the significant role of E11,E13-16:Ald as a major component and a clear synergistic effect of the two monoenyl compounds as a minor component. Although the 3:3:7 mixture of Z11-14:OAc, E11-16:Ald, and E11,E13-16:Ald captured the largest number of males among the tested mixtures, the activity was still quite a bit lower than that of virgin females. However, the 3:3:7:1 mixture, which was prepared by adding a small amount of Z3,Z6,Z9-23:H to the 3:3:7 ternary lure, succeeded in attracting males more powerfully than the females did. This strong synergistic effect was not observed when the triene was added to unmixed E11,E13-16:Ald, indicating important roles of not only the triene but also the two monoenyl compounds as natural pheromone components.     

Interference with the mate-finding communication system of the Chinese tortrix Cydia trasias (Lep., Olethreutidae) using synthetic sex pheromones

Abstract: Interference with the mate-finding communication system of Cydia trasias (Meyrick) using sex pheromone dispensers (60% E8,E10-dodecadienyl acetate and 40% E8,E10-dodecadien-1-ol, 0.5 mg/dispenser) was investigated in three plots of the Chinese scholar-tree, Sophora japonica L., in Beijing, China, in 2000. Treatments were evaluated by pheromone-baited traps, caged virgin females, pupating and hibernating populations on tree trunks, and assessment of larval damage in petioles and seed pods. Six to eight natural rubber septum dispensers were placed in each tree at the pheromone-treated plots at three separate periods: at the beginning of overwintering generation flight, the first- and the second-generation flights. Application of pheromone dispensers reduced the incidence of mating of virgin females in treated plots relative to those in the control plots. Pheromone-baited trap catches were lowered on average by 96%, suggesting a high level of disruption. Average larval density on tree trunks was significantly lower in the pheromone-treated plots than in the untreated control plots. The mean percentage of Chinese scholar-tree petioles infested with first- and second-generation larvae, and seed pods infested with third-generation larvae was significantly greater in untreated control plots than in pheromone-treatment plots. These results suggest that disruption of pheromone-based communication in C. trasias is prospective, with synthetic sex pheromone on trees in urban environments.     

Sex Pheromone of the Female Large Cabbage-heart Caterpillar,Crocidolomia binotalis Zeller (Lepidoptera: Pyralidae)

Sex pheromone components of the female Crocidolomia binotalis, an insect pest of cabbages in Indonesia, were identified from the ovipositor tip extract of virgin females by analyzing with chromatographic fractionation and capillary GC/MS. In an EAG response and attractivity test with a wind tunnel system, a mixture of synthetic compounds, (Z)-9-tetradecenyl acetate (Z-9- TDA) and (Z)-l 1-hexadecenyl acetate (Z-ll-HDA), in the ratio of 1:7—1:60 and an amount of 1 ~ 50 ng on a filter paper, showed strong activities comparable to the activity of the ovipositor tip extract, which contained the two compounds at a ratio of c. 1:10 (Z-9-TDA : Z-l 1-HDA). The mixture of these two compounds might be the sex pheromone of C. binotalis.     

Reidentification of the female sex pheromone of the Indian meal moth, Plodia interpunctella: evidence for a four-component pheromone blend

Pheromone gland extracts from calling female Plodia interpunctella contained at least seven compounds that consistently elicited electroantennographic responses from male antennae upon gas chromatographic analysis. Three of these compounds were found to be the previously identified gland constituents, i.e., (Z,E)-9,12-tetradecadienyl acetate (Z9,E12-14:OAc), (Z,E)-9,12-tetradecadienal (Z9,E12-14:Ald) and (Z,E)-9,12-tetradecadienol (Z9,E12-14:OH). A fourth EAD-active compound was identified as (Z)-9-tetradecenyl acetate (Z9-14:OAc). The homologue (Z)-11-hexadecenyl acetate (Z11-16:OAc) was also identified in the extracts, but showed no EAD activity. The identity of all five compounds was confirmed by comparison of GC retention times and mass spectra with those of synthetic standards. In flight tunnel tests there were no significant differences in response of male P. interpunctella to the bait containing all four EAD-active compounds and the responses to female gland extacts. A behavioural assay of different two-compound blends in the flight tunnel showed that only addition of the corresponding aldehyde to the major pheromone component Z9,E12-14:OAc raised the male response. A subtractive assay, however, revealed that the exclusion of any of the compounds from the complete four-compound blend reduced its activity significantly. We thus conclude that the female-produced sex pheromone of P. interpunctella consists of at least four components, i.e., Z9,E12-14:OAc, Z9,E12-14:Ald, Z9,E12-14:OH and Z9-14:OAc.In a field trapping test performed in a storage facility, the four-component blend attracted significantly more males of P. interpunctella than traps baited with Z9,E12-14:OAc alone. In contrast, the highest number of Ephestia kuehniella males was found in the traps baited with this major component, suggesting that the secondary pheromone components contribute to the species specificity of the blend.     

Altered olfactory receptor neuron responsiveness in rare Ostrinia nubilalis males attracted to the O. furnacalis pheromone blend

Three percent of E-strain Ostrinia nubilalis males fly upwind in response to the Ostrinia furnacalis pheromone blend [a 40:60 ratio of (E)-12-tetradecenyl acetate to (Z)-12-tetradecenyl acetate (E12-14:OAc to Z12-14:OAc)], in addition to their own pheromone blend [a 99:1 ratio of (E)-11-tetradecenyl acetate to (Z)-11-tetradecenyl acetate) (E11-14:OAc to Z11-14:OAc)]. We assessed the olfactory receptor neuron (ORN) responses of these behaviorally "rare" males versus those of normal males. For the three ORNs housed within each sensillum, we tested responsiveness to Z12-14:OAc, E12-14:OAc, Z11-14:OAc, E11-14:OAc, and the behavioral antagonist (Z)-9-tetradecenyl acetate (Z9-14:OAc). Z11-14:OAc, E11-14:OAc, and Z9-14:OAc stimulated ORNs exhibiting distinct small, large, and medium spike sizes, respectively. For rare and normal males, both Z12-14:OAc and E12-14:OAc usually elicited responses from the largest-spiking ORN. In many ORNs of normal males, Z12-14:OAc or E12-14:OAc stimulated the smaller-spiking ORN that is responsive to Z11-14:OAc. In rare males, detectable ORN responses from the smaller-spiking ORN in response to Z12- and E12-14:OAc were virtually non-existent. These differences in ORN tuning in rare males will tend to create an ORN firing ratio between the large- and small-spiking ORNs in response to the O. furnacalis blend that is similar to that elicited by the O. nubilalis blend.     

Behavioural effects of minor sex pheromone components in Brazilian apple leafroller Bonagota cranaodes (Lep., Tortricidae)

Abstract:  The behavioural response of Brazilian apple leafroller males, Bonagota cranaodes (Meyrick), to natural and synthetic sex pheromone was studied in a wind tunnel. Calling females elicited upwind flights followed by landing and wingfanning at the source in 72% of the males tested. Female gland extracts, with the main compound ( E , Z )3,5dodecadienyl acetate released at 100 pg/min, attracted 57% of the males to the source. Few males (1%) were attracted to the main compound alone, released at the same rate. Even a synthetic blend of all five gland compounds eliciting an antennal response, formulated according to their proportion in female gland extracts, was barely attractive (7%). Comparison of this synthetic blend and female gland extracts indicates a behavioural role of other gland compounds. Male attraction was significantly increased (34%) in response to a 100 : 5 : 5 : 5-blend of the main compound and three minor gland compounds, ( Z )-5-dodecenyl acetate, ( E , Z )-3,5-tetradecadienyl acetate, and ( Z )-9-hexadecenyl acetate.     

Antennal sensitivity to female sex pheromone compounds of Spodoptera frugiperda males (Lepidoptera: Noctuidae) and associated field behaviour

The fall armyworm (FAW), Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae), is one of the most important insect pests of corn, sorghum, rice, and grasses. The sex pheromone produced by S. frugiperda is composed of a mixture of esters. In this study, I determined the antennal responses of FAW males from 22 populations in Mexico to the components of the sex pheromone of this species: (Z)-7-dodecenyl acetate (Z7-12:OAc), (Z)-9-tetradecenyl acetate (Z9-14:OAc), and (Z)-11-hexadecenyl acetate (Z11-16:OAc) at four doses (0.01, 0.1, 1, and 10 μg). In addition, I evaluated the behavioural activity of single compounds in the field. The largest antennal responses of FAW males from all the sampled regions were elicited by Z9-14:OAc (all doses evaluated) and Z7-12:OAc (0.01, 0.1, and 1 μg). The male antennal responses evoked by Z11-16:OAc were smaller but similar to responses to Z7-12:OAc at lower doses (0.01 and 0.1 μg). In the field test, Z9-14:OAc produced significantly higher captures of S. frugiperda males compared to Z7-12:AOc and Z11-16:OAc. Antennal responses were related to captures obtained in the field, supported by the positive correlation of these variables [electroantennography (EAG) response and behaviour], with the exception of Z7-12:OAc, which elicited relatively large EAG responses but did not produce high captures of S. frugiperda. These results are of importance to agriculture, enabling the implementation of better methods of monitoring and controlling this pest, and support the suggestion that a mixture of Z9-14:OAc and Z7-12:OAc could represent an effective attractant for all evaluated populations of S. frugiperda in Mexico.     

Electrophysiological and behavioural evidence for a fourth sex pheromone component in the turnip moth, Agrotis segetum

Abstract. In addition to the pheromone components (Z)-5-decenyl, (Z)-7-dodecenyl and (Z)-9-tetradecenyl acetate (Z5-10:OAc, Z7-12:OAc and Z9-14:OAc), it has previously been shown that the sex pheromone gland of the turnip moth, Agrotis segetum (Lepidoptera: Noctuidae Schiff) contains 10:OAc, 12:OAc, Z5-12:OAc, Z9-12:OAc, 11–12:OAc, Z5-14:OAc, Z7-14:OAc and Z11-16:OAc. To find out whether any of these additional compounds is involved in the sex pheromone communication in A. segetum, a comprehensive electro-physiological and behavioural investigation was conducted. Single-sensillum recordings on male antennae revealed three subtypes of sensilla among the previously so-called Z5-10:OAc sensilla. One subtype was identified having one receptor neurone (A) that responded to Z5-10:OAc with a large spike amplitude and another neurone (B) that responded to (Z)-5-decenol (Z5-10:OH) with a small spike amplitude. In another subtype the B neurone responded to Z5-12:OAc and sometimes also to 27-12:OAc and 10:OAc, in addition to responding to Z5-10:OH. In a third subtype the A neurone responded to all acetates identified from the female pheromone gland, whereas the small spike amplitude neurone was tuned to Z5-10:OH. A flight tunnel assay showed that blends composed of nine, eight or seven compounds were equivalent to the previously identified three-component pheromone blend in eliciting male behavioural responses. In field trapping tests, blends of eleven, nine or seven compounds did, however, catch significantly more moths than the three-component blend. Further assays showed that only 25- 12:OAc could significantly increase the catch numbers when added to the three-component blend, and thus qualified as a fourth pheromone component in A. segerum. The behavioural significance of additional female-produced acetates — for which males possess antennal receptors — is suggested, but may be impossible to confirm because of ‘diminishing returns’ when trying to refine a multicomponent pheromone further.     

Identification of the Sex Pheromone of the Tree Infesting Cossid Moth Coryphodema tristis (Lepidoptera: Cossidae)

The cossid moth (Coryphodema tristis) has a broad range of native tree hosts in South Africa. The moth recently moved into non-native Eucalyptus plantations in South Africa, on which it now causes significant damage. Here we investigate the chemicals involved in pheromone communication between the sexes of this moth in order to better understand its ecology, and with a view to potentially develop management tools for it. In particular, we characterize female gland extracts and headspace samples through coupled gas chromatography electro-antennographic detection (GC-EAD) and two dimensional gas chromatography mass spectrometry (GCxGC-MS). Tentative identities of the potential pheromone compounds were confirmed by comparing both retention time and mass spectra with authentic standards. Two electrophysiologically active pheromone compounds, tetradecyl acetate (14:OAc) and Z9-tetradecenyl acetate (Z9-14:OAc) were identified from pheromone gland extracts, and an additional compound (Z9-14:OH) from headspace samples. We further determined dose response curves for the identified compounds and six other structurally similar compounds that are common to the order Cossidae. Male antennae showed superior sensitivity toward Z9-14:OAc, Z7-tetradecenyl acetate (Z7-14:OAc), E9-tetradecenyl acetate (E9-14:OAc), Z9-tetradecenol (Z9-14:OH) and Z9-tetradecenal (Z9-14:Ald) when compared to female antennae. While we could show electrophysiological responses to single pheromone compounds, behavioral attraction of males was dependent on the synergistic effect of at least two of these compounds. Signal specificity is shown to be gained through pheromone blends. A field trial showed that a significant number of males were caught only in traps baited with a combination of Z9-14:OAc (circa 95% of the ratio) and Z9-14:OH. Addition of 14:OAc to this mixture also improved the number of males caught, although not significantly. This study represents a major step towards developing a useful attractant to be used in management tools for C. tristis and contributes to the understanding of chemical communication and biology of this group of insects.     

Female sex pheromone of Athetis lepigone (Lepidoptera: Noctuidae): Identification and field evaluation

Athetis lepigone has been recorded in many countries in Europe and Asia, but it had never been documented as an agricultural pest until 2005. For the purpose of using the sex pheromone to control this pest, we conducted a study to identify the sex pheromone of A. lepigone by gas chromatography with an electroantennographic detector (GC‐EAD) and GC coupled with mass spectrometry (GC/MS) analyses. Three pheromone candidates were detected by GC‐EAD analysis in the extracts of the female sex pheromone gland, and two candidates were identified as (Z)‐7‐dodecenyl acetate (Z7‐12:OAc) and (Z)‐9‐tetradecenyl acetate (Z9‐14:OAc) in a ratio of 1:5 by mass spectral analysis of natural pheromone components and dimethyl disulphide adducts. In the field male trapping test, the traps baited with the binary blend captured high number of males, while traps with single component hardly caught males, indicating that the two components are essential for the male attractiveness. In addition, the optimum ratios of Z7‐12:OAc and Z9‐14:OAc were determined as 3:7–7:3, and the best doses for the binary blend (at ratio of 3:7 between Z7‐12:OAc and Z9‐14:OAc) were 0.25–0.5 mg/trap, based on the number of male catches. The identification of a highly attractive sex pheromone will help in developing efficient strategies for monitoring and control of A. lepigone.     

中国印度谷螟性信息素次级组份的研究

印度谷螟是我国危害性较严重的仓储害虫之一,食性很广,几乎危害每一种植物性仓储物.印度谷螟雌虫性信息素主要成份顺9,反12-十四碳二烯醇醋酸酯(TDA)早已被鉴定,并利用TDA单一组份诱捕印度谷螟雄蛾也较为有效,但该虫的完整信息素系统尚不清楚.本研究采用单个雌蛾性信息素腺体抽提技术,利用毛细管气相色谱GC保留时间定性方法和气质联用GC-MS分析鉴定技术,从印度谷螟雌虫腺体提取物中鉴定了顺9,反12-十四碳二烯醇醋酸酯(A),顺9,反12-十四碳二烯醇(B),顺9,反12-十四碳二烯醛(C)和顺9-十四碳醋酸醋(D)4种主要信息素成份,其比例为A∶B∶C∶D=100∶22∶12∶9.风洞试验结果表明,以该4种主要成分按A∶B∶C∶D=8∶2∶1∶0.8比例配制成的诱芯,其引诱雄蛾的活性接近于雌蛾腺体提取物.     

Sex pheromone biosynthesis in the tortricid moth Planotortrix excessana (Walker) involves chain-shortening of palmitoleate and oleate

Biosynthesis of the sex pheromone components, (Z)-5-tetradecenyl acetate (Z5-14:OAc) and (Z)-7-tetradecenyl acetate (Z7-14:OAc), was investigated in the New Zealand tortricid moth Planotortrix excessana (Walker) by fatty acid methyl ester (FAME) analysis of base-methanolyzed extracts of lipids in the sex pheromone gland and through application of various labelled fatty acids. Analysis of the base-methanolyzed gland extracts revealed common FAMEs, including methyl oleate and methyl palmitoleate, as well as the FAMEs of the putative precursors, methyl (Z)-5-tetradecenoate and methyl (Z)-7-tetradecenoate. Application of labelled, saturated fatty acids, myristic, palmitic, and stearic did not result in any significant incorporation of label into either of the unsaturated pheromone components, although label was incorporated into tetradecyl acetate (14:OAc). In contrast, application of labelled oleic acid resulted in incorporation of label into Z5-14:OAc but not into Z7-14:OAc or into 14:OAc, whereas application of labelled palmitoleic acid resulted in incorporation of label into Z7-14:OAc but not into Z5-14:OAc or 14:OAc. These data support a route for biosynthesis of Z5-14:OAc and Z7-14:OAc in this species by limited β-oxidation of the common fatty acyl moieties, respectively, oleate (involving two cycles of 2-carbon chain-shortening) and palmitoleate (involving only one cycle of 2-carbon chain-shortening), and apparently involving no desaturase (other than the common Δ9) specific to sex pheromone biosynthesis. Interestingly, P. excessana females biosynthesize the same component (Z5-14:OAc) from an entirely different route from that of the related species Ctenopseustis obliquana (which biosynthesizes Z5-14:OAc by Δ5-desaturation of myristate). Additionally, the pheromone biosynthesis activating neuropeptide (PBAN) stimulates pheromone biosynthesis in this species. Arch. Insect Biochem. Physiol. 37:158–167, 1998. © 1998 Wiley-Liss, Inc.