Sex pheromone components of the leafroller moth Pandemis cerasana

Female-tip washings of the leafroller moth, Pandemis cerasana, were found to contain (E)-11-tetradecenyl acetate, (Z)-11-tetradecenyl acetate, (E)-11-tetradecenol, (Z)-11-tetradecenol and tetradecyl acetate, based on chemical analysis and electroantennogram tests. The relative amounts of these compounds in the gland were ca. 64:21:10:3:2 in the order named. Only (E)-11 and (Z)-11-tetradecenyl acetate were required for attraction of males to trap dispensed in the ratio 3:1, respectively.     

Electroantennogram responses of the male moth, Argyrotaenia velutinana to mixtures of sex pheromone components of the female

Electroantennogram (EAG) responses were recorded from male redbanded leafroller moth, Argyrotaenia velutinana, antennae using mixtures of the three female-produced sex pheromone components: cis-11-tetradecenyl acetate, trans-11-tetradecenyl acetate, and dodecyl acetate (12:Ac). Binary mixtures containing 3%, 8%, and 15% trans in cis elicited significantly higher amplitude responses than other isomeric mixtures as well as pure cis and trans alone. The higher responses to such mixtures were less than additive at high dosages and additive at lower dosages. Receptor adaptation studies using the two isomers support a previous single unit study demonstrating the presence of at least two functionally different receptor sites on male A. velutinana antennae; adaptation to an airstream containing one isomer did not eliminate response to the opposite isomer presented concurrently. An airstream containing the third component, 12:Ac, caused a significant slowing of the recovery rate during the entire recovery period of EAG responses to cis but not trans, suggesting that a possible temporal modulation of neuronal response by 12:Ac may be a means of coding for this component by antennal sensory neurons.     

Electroantennogram responses of two tortricid moths using two-component sex pheromones

Antennal responses of male Adoxophyes orana and Clepsis spectrana to their two pheromone components, cis-9- and cis-11-tetradecenyl acetate (tda) were studied. Responses to a dilution series of the components alone and in five mixture ratios were recorded. The main pheromone component for A. orana (cis-9-tda) and for C. spectrana (cis-11-tda) gave the highest electroantennogram (EAG) responses, respectively, but mixtures corresponding to the optimum field attracting ratios for each species elicited higher responses than the separate components.The geometrical isomers, trans-9- and trans-11-tda, which inhibit male A. orana response in the field, do not appear to give an additive EAG response when mixed with the pheromone components.     

Broadly and narrowly tuned odorant receptors are involved in female sex pheromone reception in Ostrinia moths

Mate-finding communication in many moths is mediated by sex pheromones produced by females. Since the differentiation of sex pheromones is often associated with speciation, it is intriguing to elucidate how the changes in sex pheromones are tracked by the pheromone recognition system of the males. Moths of the genus Ostrinia, which show distinct differentiation in female sex pheromones, are good models to study this. The present study was initiated with the aim of identifying ORs from Ostrinia scapulalis that respond to its own pheromone components, (E)-11- and (Z)-11-tetradecenyl acetates. We isolated six OR gene candidates (OscaOR3–8) from O. scapulalis. The same set of genes homologous to OscaOR3–8 were conserved in all (eight) Ostrinia species examined in addition to the previously reported OscaOR1 (tuned to (E)-11-tetradecenol) and the Or83b homologue OscaOR2. OscaOR3 not only responded to (E)-11- and (Z)-11-tetradecenyl acetates, but also to the pheromone components of the congeners, (Z)-9-, (E)-12-, and (Z)-12-tetradecenyl acetates. OscaOR4 responded with a relatively high specificity to (E)-11-tetradecenyl acetate. While OscaOR5 responded only marginally to a few pheromone components, OscaOR6–8 did not respond to any of the compounds tested. A few conserved ORs, including a unique one with very broad responsiveness, appear to be involved in the sex pheromone reception in O. scapulalis. The findings of the present study are discussed with reference to knowledge on electrophysiological response profiles of olfactory receptor neurons in Ostrinia moths.     

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.     

Inhibition of sexual response in males of the moth Argyrotaenia velutinana by brief exposures to synthetic pheromone or its geometrical isomer

When cis-11-tetradecenyl acetate (RiBLuRe) and its geometrical isomer, trans-11-tetradecenyl acetate were simultaneously presented to male red-banded leaf roller moths their response was significantly lower than that to an equal quantity of RiBLuRe alone. When the males were exposed to RiBLuRe for a duration of 10 min at times up to 60 min before bioassay there was a complete absence of response to RiBLuRe at the time of bioassay. Similar exposure to an equal quantity of the trans-isomer before bioassay resulted in significant reduction of the response to RiBLuRe at the subsequent bioassay but without complete inhibition.     

Notes on New Zealand mammals 10. Effect of observer position on group size and level of aggression of mating brown hares

Abstract

The sex pheromones of two endemic New Zealand tortricid species were investigated. Females of the first species, Cnephasia jactatana, a pest of kiwifruit, were found to produce (Z)-11-tetradecenyl acetate (Z11-14:OAc) in their sex pheromone gland. When tested in the field, this compound on its own elicited significant catches of male C. jactatana. However, the addition of even very small amounts (0.3%) of the geometric isomer, (E)-11-tetradecenyl acetate (E11-14:OAc), to Z 11-14:OAc virtually suppressed trap catches. The sex pheromone of the second species, Merophyas leucaniana, was found to consist of a mixture of Z11-14:OAc, E11-14:OAc, tetradecyl acetate, and (Z)-11-tetradecenol. This species is morphologically very similar to the congeneric species, M. divulsana, the Australian lucerne leafroller. The sex pheromone of M. leucaniana is also very similar to that of the so-called “Z-type” of M. divulsana, which is now found in New Zealand. The pheromone components of C. jactatana and M. leucaniana are discussed in relation to those found in other tortricids.     

Sex pheromone of the moth,Antheraea polyphemus

The sex pheromone system of Antheraea polyphemus was characterized from female abdominal tips by classical and electroantennogram techniques as rans-6,cis-11-hexadecadienyl acetate and trans-6,cis-11-hexadecadienal. A 90 : 10 mixture of acetate and aldehyde was highly attractive to wild males in the field. The synthetic pheromone and A. polyphemus females were not attractive to released Antheraea pernyi males.     

Behavioural and electrophysiological activity of unsaturated analogues of the pheromone tetradecyl acetate in the small ermine moth Yponomeuta rorellus

ABSTRACT In field-trapping experiments the unsaturated analogues ( E )-6-, ( E )-12-, and ( Z )-12-tetradecenyl acetate were as attractive to male Yponomeuta rorellus Latr. as the native pheromone component tetradecyl acetate. All four analogues attracted more males than virgin females did, whereas ( Z )-6-, ( E )-11-, ( Z )-10- and ( Z )-11-tetradecenyl acetate were essentially non-attractive. Addition of 1–30% of ( Z )-11-tetradecenyl acetate to the pheromone tetradecyl acetate reduced the attraction to less than 2%. Flight tunnel experiments with Y. rorellus confirmed the activity of the ( E )-6- and ( E )-12-tetradecenyl acetates and demonstrated the activity of ( E )-7-tetradecenyl acetate as well. These analogues elicited orientation behaviour, upwind flight and landing at the odour source as frequently as the native pheromone did. Single sensillum recordings from male Y. rorellus showed two types of cells in most sensilla. A large spike amplitude cell was stimulated by tetradecyl acetate and the unsaturated analogues ( E )-11-, ( E )-6- and ( E )-12-tetradecenyl acetate, and to a lower extent by the ( Z )-6-, ( Z )-11- and ( Z )-12-isomers. A cell with medium spike amplitude was stimulated by ( Z )-9-tetradecenyl and ( Z )-11-hexadecenyl acetate. Some sensilla contained a third cell firing with a small spike amplitude which was activated by ( Z )-11-tetradecenol. Thus the tetradecyl acetate receptor was stimulated not only by the behaviourally active analogues, but also by behavioural antagonists. The interaction of ( E )-11-tetra-decenyl acetate and tetradecyl acetate with the same antennal receptor cell was also demonstrated in Y.cagnagellus . Electrophysiological discrimination between behavioural attractants and antagonists and the role of behavioural antagonists in the interspecific relations between Y.rorellus and sympatric closely related species are discussed.     

Biosynthesis of the acetate ester precursor of the spruce budworm sex pheromone by an acetyl CoA: Fatty alcohol acetyltransferase

The biosynthesis of 11-tetradecenyl acetate, the major storage precursor of the aldehyde pheromone of Choristoneura fumiferana, the eastern spruce budworm, has been found to be catalyzed by an acetyl-CoA: fatty alcohol acetyltransferase. In vitro, acetyltransferase activity was found almost exclusively in extracts from the pheromone producing gland, and could be demonstrated in vivo by topical application of [¹⁴C]tetradecanol to the glands. Moreover, the activity was under developmental regulation, being low before and immediately after emergence of the moths from the pupal stage, and rising to a maximum in concert with the increase in glandular pheromone levels. Maximum activity with saturated alcohols was observed for acceptors of 12 to 15 carbons in chain length, with higher activities being found for the cis or trans monounsaturated analogs. The specificity of this enzyme with respect to substrate, morphological location and developmental regulation, indicates that it plays a key role in regulation of pheromone biosynthesis.     

Pheromone-gland-specific fatty-acyl reductase in the adzuki bean borer,Ostrinia scapulalis (Lepidoptera: Crambidae)

The adzuki bean borer moth, Ostrinia scapulalis, uses a mixture of (E)-11- and (Z)-11-tetradecenyl acetates as a sex pheromone. At a step in the pheromone biosynthetic pathway, fatty-acyl precursors are converted to corresponding alcohols by an enzyme, fatty-acyl reductase (FAR). Here we report the cloning of FAR-like genes expressed in the pheromone gland of female O. scapulalis, and the characterization of a single pheromone-gland-specific FAR (pgFAR) and its functional assay using an insect cell expression system. As many as thirteen FAR-like genes (FAR-I–FAR-XIII) were expressed in the pheromone gland of O. scapulalis; however, only one (FAR-XIII) was pheromone-gland-specific. The deduced amino acid sequence of FAR-XIII predicted a 462-aa protein with a conserved NAD(P)H-binding motif in the N-terminal region, showing overall identity of 34% with the pgFAR of Bombyx mori. A functional assay using Sf9 cells transfected with an expression vector containing the open reading frame of the FAR-XIII gene has proven that FAR-XIII protein has the ability to convert a natural substrate, (Z)-11-tetradecenoic acid, to a corresponding alcohol, (Z)-11-tetradecenol.     

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.     

Effects of egg-to-adult development time and adult age on olfactory neuron response to semiochemicals in European corn borers

We used the cut-sensillum technique to assess the effect of both adult age and egg-to-adult development time on olfactory neuron responses of Z strain moths of the European corn borer, Ostrinia nubilalis. Compounds tested included the pheromone components, (Z)-11-tetradecenyl acetate and (E)-11-tetradecenyl acetate, the behavioral antagonist, (Z)-9-tetradecenyl acetate, and components of the O. furnicalis (Asian corn borer) sex pheromone, (Z)-12-tetradecenyl acetate and (E)-12-tetradecenyl acetate. The proportion of moths having neurons responding to the two O. nubilalis sex pheromone components and antagonist increased with longer development time and age. The spike frequency of neurons responding to (E)-11-tetradecenyl acetate and the antagonist increased with longer development time. Fourteen of 45 moths with neurons sensitive to either of the O. nubilalis pheromone components responded to (Z)-12-tetradecenyl acetate or (E)-12-tetradecenyl acetate. The likelihood of (Z)-12-tetradecenyl acetate stimulating a neuron similar in spike shape and waveform to that responding to (E)-11-tetradecenyl acetate increased with development time.     

Relative attractiveness of incomplete and complete blends of synthetic pheromone to male obliquebanded leafroller (Lepidoptera: Tortricidae) moths in a flight tunnel and in apple orchards: implications for sex pheromone-mediated mating disruption of this species

The relative attractiveness of synthetic Choristoneura rosaceana (Harris) pheromone consisting of the major compound Z-11-tetradecenyl acetate (Z11-14:OAc), or the major compound plus one, two, or all three of the minor compounds E-11-tetradecenyl acetate (E11-14:OAc), Z-11-tetradecenol (Z11-14:OH), and Z-11-tetradecenal (Z11-14:Ald), in amounts similar to those in the natural pheromone, was compared in a flight tunnel and in apple orchards. In the flight tunnel, there was an increase in the proportion of moths that were activated when E11-14:OAc was combined with the main compound, but no detectible additional increases in response with the addition of Z11-14:OH and Z11-14:Ald. The time required for activation was twice as long when using the major compound than when using the major compound and one or more of the minor compounds. There was a trend of increase in the proportion of males initiating the take-off, lock-on, close-in, and touchdown phases of upwind flight when progressively more complete blends were used. The time required for the initiation of these behavioral phases was statistically similar for each treatment. The proportion of moths landing at the pheromone source was 10 times greater when using the complete blend than when using the main compound alone. Similar results were obtained in apple orchards, where the four-compound blend was 17-55 times more attractive than the main compound. The superior attractiveness of the four-compound pheromone compared with the major compound, or to the major compound plus the minor compound E11-14:OAc, suggests that it would be the most effective synthetic pheromone if competitive attraction were an important mechanism of disruption in this species.     

Field trials of synthetic sex pheromone lures for the large cabbage-heart caterpillar moth, Crocidolomia pavonana (Lepidoptera: Crambidae) in Indonesia

The efficacy of synthetic female sex pheromone lures for Crocidolomia pavonana (Fabricius) (Lepidoptera: Crambidae) in the cabbage fields of Java and Bali, Indonesia, was investigated by varying the composition and dosage of the components. The lure containing a synthetic pheromone blend of (Z)-11-hexadecenyl acetate (Z11–16: Ac) and (Z)-9-tetradecenyl acetate (Z9–14: Ac) at a 10:1 ratio acquired significantly more male catches than single component lures and the control lure. Meanwhile, no attraction was observed when lures with 1:1 and 1:10 blends were tested. The composition of Z11–16: Ac and Z9–14: Ac at a ratio of 5, 10 and 20:1 attracted more males than the control lures. Dosage studies showed that 0.055 and 0.55 mg of a mixture of Z11–16: Ac and Z9–14: Ac (10:1 ratio) attracted more males than the control. These results are the first demonstration of the efficacy of synthetic pheromone for C. pavonana in field conditions. The present study suggests the feasibility of pheromone-based monitoring as a simple and low-cost technique for integrated pest management of this pest.     

Sex pheromone composition of the variegated cutworm,Peridroma saucia (Lepidoptera: Noctuidae), in Korea

This study was conducted to investigate the sex pheromone composition of the variegated cutworm (Peridroma saucia Hübner) in Korea. The sex pheromone components of P. saucia were identified as (Z)-9-tetradecenyl acetate (Z9-14:Ac) and (Z)-11-hexadecenyl acetate (Z11-16:Ac) through GC-EAD and GC–MS analysis. EAG tests of the male antennae revealed that the Z9-14:AC exerted significantly larger responses than other compounds. The female moths primarily called and copulated between 6 h and 7 h after the lights off, and the ratio of two pheromone components, Z9-14:Ac and Z11-16:Ac, in the sex pheromone gland during this period was 1:2.1 to 1:2.4. In the field trapping studies, a large number of male moths were caught in the traps baited with the mixtures of Z9-14:Ac and Z11-16:Ac at the ratios ranging from 2.3:1 to 1:4, with the highest trap catches at 1:1 to 1:2.3 ratios of the two components. The seasonal flight activities of P. saucia monitored by using pheromone lures revealed complicated patterns in Korea. Specifically, the first flight period was spread over a long period and irregular, while the second flight period differed among the localities examined.     

A male-specific odorant receptor conserved through the evolution of sex pheromones in Ostrinia moth species

In many moths, mate-finding communication is mediated by the female sex pheromones. Since differentiation of sex pheromones is often associated with speciation, it is intriguing to know how the changes in female sex pheromone have been tracked by the pheromone recognition system of the males. A male-specific odorant receptor was found to have been conserved through the evolution of sex pheromone communication systems in the genus Ostrinia (Lepidoptera: Crambidae). In an effort to characterize pheromone receptors of O. scapulalis, which uses a mixture of (E)-11- and (Z)-11-tetradecenyl acetates as a sex pheromone, we cloned a gene (OscaOR1) encoding a male-specific odorant receptor. In addition, we cloned a gene of the Or83b family (OscaOR2). Functional assays using Xenopus oocytes co-expressing OscaOR1 and OscaOR2 have shown that OscaOR1 is, unexpectedly, a receptor of (E)-11-tetradecenol (E11-14:OH), a single pheromone component of a congener O. latipennis. Subsequent studies on O. latipennis showed that this species indeed has a gene orthologous to OscaOR1 (OlatOR1), a functional assay of which confirmed it to be a gene encoding the receptor of E11-14:OH. Furthermore, investigations of six other Ostrinia species have revealed that all of them have a gene orthologous to OscaOR1, although none of these species, except O. ovalipennis, a species most closely related to O. latipennis, uses E11-14:OH as the pheromone component. The present findings suggest that the male-specific receptor of E11-14:OH was acquired before the divergence of the genus Ostrinia, and functionally retained through the evolution of this genus.     

The isolation and identification of the female sex pheromones of the red bollworm moth, Diparopsis castanea

The female sex pheromones of the red bollworm moth, Diparopsis castanea, were isolated by solvent extraction of the terminal abdominal segments of the female moth followed by purification of the solvent extract by liquid-solid and gas chromatography. The pheromones were identified by gas chromatographic analysis, micro-ozonolysis, infra-red and mass spectroscopy, and comparison with synthetic material. The major pheromone was 9,11-dodecadien-1-yl acetate (80 : 20 trans : cis). Minor components identified were trans 9-dodecen-1-yl acetate, 11-dodecen-1-yl acetate, and dodecan-1-yl acetate.     

Sex pheromone of the cotton leafworm, Spodoptera littoralis

cis-9,trans-11-Tetradecadien-1-ol acetate (A) and cis-9,trans-12-tetradecadien-1-ol acetate (B), the same compounds as the female sex pheromone of Spodoptera litura, were identified as major components of the female sex pheromone of the cotton leafworm, Spodoptera littoralis. Compounds A and B were individually active, but the activity was synergistically enhanced by mixing the two compounds. The male response was optimal with mixture ranging from 5 : 1 to 20 : 1 of compounds A and B, respectively. Fifty per cent of the male moths of S. littoralis responded to the 20 : 1 mixture at the 10^?7 μg level; they responded at a concentration 100-fold lower than did male moths of S. litura. A partially purified extract of females of S. litura stimulated male moths of S. littoralis. Similarly a partially purified extract of S. littoralis was also active for the male moths of S. litura. The extract of females of S. litura, however, was 1000 times less active for male moths of S. littoralis than was the exrtact of females of S. littoralis, suggesting that a compound(s) is present in the extract of S. litura that inhibits the response of males of S. littoralis.