P. S. Beevor

1-Octen-3-ol. A potent olfactory stimulant and attractant for tsetse isolated from cattle odours

Recording of electroantennographic (EAG) responses from tsetse, Glossina pallidipes and G. morsitans morsitans (Diptera: Glossinidae) has been used to detect olfactory stimulants in volatiles from cattle. The most potent stimulant in cattle odours collected on Porapak resin has been identifiedas 1-octen-3-ol by gas chromatographic retention data and mass spectrometry. The rate of production of 1-octen-3-ol by a normal ox was estimated to be 0.043 mghr−1, and the natural material was shown to be predominantly the (R)-(−)enantiomer. No 1-octen-3-ol was collected under the conditions used in the absence of an ox. EAG dose-response curves to 1-octen-3-ol showed it to be about 106 times more potent than acetone, a known attractant for tsetse, with the maximum response of about 1 mV occurring to approx. 1 ng at source. 1-octen-3-ol caused increased upwind flight by tsetse in a wind tunnel bioassay, and in the field it was attractive to tsetse by itself and also increased the attractiveness of both ox odour and of mixtures ofcarbon dioxide and acetone.RésuméLes réponses électroantennographique (EAG) des mouches tsé-tsé, Glossina pallidipes et G. morsitans morsitans (Diptera: Glossinidae), ont été notées afin de découvrir les stimulants olfactifs parmi les composés volatils émanant du bétail. Le stimulant le plus puissant dans l’odeur de bétail, recueillié sur la résine Porapak, a été identifié comme 1-octen-3-ol en utilisant des données de rétention chromatographique en phase gazeuse et spectrométrie de mass. On a estimé le taux de production de 1-octen-3-ol par un boeuf normal à 0,043 mg hr−1 et la matiére naturelle s’est révélée comme composée en majeure partie de l’enantiomère (R)-(−). Dans les conditions utilisées, on n’a recueillié de 1-octen-3-olqu’enpresence d’un boeuf. Les courbes de dosage-réponse EAG pour 1-octen-3-ol l’a révélé à peu près 106 fois plus puissant que l’acétone, un attractant connu pour les mouches tsé-tsé, la réponse maximum d’environ 1 mV étant enregistrée pour environ 1 ng à la source. 1-octen-3-ol a occasionne un accroissement de vol des mouches tsé-tsé contre le vent dans un tunnel aérodynamique. Sur le terrain 1-octen-3-ol s’est révélé attractif tout seul et a augmenté la puissance attractive de l’odeur de boeuf et aussi dés mélanges de bioxyde de carbone et d’acétone.

Identification of the female sex pheromones of the moth, Chilo suppressalis.

Abstract The female sex pheromone complex of the striped rice borer, Chilo suppressalis, has been shown to consist of two compounds: (Z)-11-hexadecenal (I) and (Z)-13-octadecenal (II). The pheromones were identified by gas chromatographic analysis, electroantennogram recording, ozonolysis, and comparison with synthetic material.

(E,E)-10,12-Hexadecadienal: A component of the female sex pheromone of the spiny bollworm,Earias insulana (Boisd.) (Lepidoptera: Noctuidae)

(E,E)-10,12-Hexadecadienal has been identified as a component of the sex pheromone of the female spiny bollworm moth,Earias insulana, by gas-chromatographic, electroantennographic and microchemical studies of abdominal tip extracts and entrained volatiles from female moths.

Female sex pheromone components of the cotton bollworm, Heliothis armigera

Abstract Detailed examination of abdominal tip extracts from adult female Heliothis armigera revealed the presence of two components which elicit electroantennographic responses from the male moth. These olfactory stimulants have been fully identified as (Z)-11-hexadecenal (I) and (Z)-11-hexadecen-1-ol(II), and detected in airborne volatiles from a ‘calling’ female moth. A third olfactory stimulant was detected only in female tip extracts from some moths of Malawi origin, and this was tentatively identified as (Z)-9-hexadecenal (III). No other olfactory stimulants could be found, although hexadecenal (IV) and 1-hexadecan-1-ol (V) were detected by gas chromatography. In field tests in Malawi, (Z)-11-hexadecenal (I) attracted a few male H. armigera moths to traps but was very much less attractive than the virgin female moth. The attractiveness of (I) was not consistently affected by addition of alcohol (II), aldehydes (III) and (IV), or (E)-11-hexadecenal. Significant numbers of male Earias biplaga moths were found to be attracted to (Z)-11-hexadecenal (I).

Components of the sex pheromone of the female spotted stalk borer,Chilo partellus (Swinhoe) (Lepidoptera: Pyralidae): Identification and preliminary field trials

FemaleChilo partellus (Swinhoe) abdominal tip extracts were examined by gas-liquid chromatography (GLC) combined with simultaneous electroantennographic (EAG) recording from the male moth. Two olfactory stimulants were detected and identified as (Z)-11-hexadecenal (I) and (Z)-11-hexadecen-1-ol (II) by their GLC behavior, microchemical reactions, and comparison with synthetic materials. Both compounds were detected in volatiles emitted by the “calling” female moth. Synthetic (Z)-9-tetradecenyl formate, a structural analog of aldehyde (I), also elicited a significant EAG response from the male moth. Field trials carried out in India using synthetic (I) and (II) as bait in water traps showed that compound (I) was highly attractive to maleC. partellus; compound (II) was not attractive, and its addition to (I) significantly reduced trap catches.

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

Abstract 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.

(Z)-9-Hexadecenal: a minor component of the female sex pheromone of Heliothis armigera (Hubner) (Lepidoptera, Noctuidae).

We recently reported the identification of up to five pheromone components in abdominal tip extracts of female Heliothis armigera and in volatiles emitted by the virgin female moth (Nesbitt et al., 1979). These were (Z)-I 1-hexadecenal (I), the major component previously identified by Piccardi et al. (1977, (Z)-11-hexadecen1-ol (II), (Z)-9-hexadecenal (III), hexadecanal (IV) and 1-hexadecanol (V). The (Z)-9-hexadecenal (III) was only found in some batches of insects from Malawi when it was present in amounts similar to those of (I). Field trapping in Malawi and elsewhere with (Z)-I 1-hexadecenal (I) alone gave low and erratic catches of male H. armigera moths, and addition of components (II), (III) and/or (IV) did not have any consistent effect on the attractiveness. However, there were suggestions from this and other work carried out in Australia (G.H.L. Rothschild, pers. comm.) that the addition of small percentages of (Z)-9-hexadecenal (III) enhanced the attractiveness of the major component (I). It was also reported by Klun et al. (1979) that in H. zea, a New World species closely related to H. armigera, the female moth produces trace amounts of (Z)-7and (Z)-9-hexadecenal and hexadecanal in addition to the major component, (Z)-ll-hexadecenal. The attractiveness of the latter to male moths was synergised by an appropriate mixture of the minor components. These findings prompted us to re-examine the pheromone system of H. armigera. Insects were collected as larvae or pupae in Malawi, India and the Sudan and flown to London. The pupae were sexed and separated, and then maintained on a reversed light/dark cycle (12 hr light at 25 ° and 70% r.h.: 12 hr dark at 20 ° and 80% r.h.). Ovipositor washings were made in carbon disulphide as described by Sower et al. (1973) and Klun et al. (1979) using female moths 2-3 days after emergence and 5-8 hr into the scotophase. The washings were analysed directly by gas chromatography (GC). After preliminary analyses on packed Carbowax 20M, OV 225 and Apiezon L columns (Nesbitt et al., 1979), more detailed analyses were carried out on glass support-coated (SCOT) and wall-coated (WCOT) opentubular columns, and also on a packed liquid crystal column (Lester & Hall, 1980). Ovipositor washings from moths of Indian origin were also examined on SCOT

Identification and synthesis of the female sex pheromone of the citrus flower moth, Prays citri

Abstract The female sex pheromone of the citrus flower moth, Prays citri , has been identified as (Z)-7- tetradecenal . The unusually small amounts of pheromone which could be extracted from the female moth precluded identification by classical methods. Instead, the basic structure of the pheromone was deduced from its gas chromatographic (GC) behaviour using a male moth prepared for electroantennographic (EAG) recording as detector; double bond position and geometry were determined by high resolution GC of the natural pheromone and a range of tetradecenal isomers, and by recording male moth EAG responses to these isomers. Synthetic (Z)-7- tetradecenal was shown to be highly attractive to male Prays citri when tested in citrus groves in Israel. This is the first reported identification of the female sex pheromone of a member of the Yponomeutidae.

Components of female sex pheromone of cocoa pod borer moth,Conopomorpha cramerella

The cocoa pod borer,Conopomorpha cramerella (Snellen) (Lepidoptera: Gracillariidae), is the most serious pest of cocoa in Southeast Asia. Analyses of ovipositor washings and entrained volatiles from virgin female moths by gas chromatography (GC) linked to electroantennography (EAG), and comparison of EAG responses from the male moth to synthetic compounds indicated the presence of theE,Z,Z andE,E,Z isomers of 4,6,10-hexadecatrienyl acetate and the corresponding alcohols, and of hexadecyl alcohol. Amounts of pheromone produced were less than 0.1 ng/female, and no peaks for the unsaturated components were observed on GC analysis. Extensive field testing of synthetic mixtures in Sabah, East Malaysia, showed that traps baited with a polyethylene vial impregnated with 1.2 mg of a mixture of the above five components in 40∶60∶4∶6∶10 ratio caught more maleC. cramerella moths than traps baited with a virgin female moth.

Field trials of the synthetic sex pheromones of the striped rice borer, Chilo suppressalis (Walker) (Lepidoptera: Pyralidae), and of related compounds

The female sex pheromones of Chilo suppressalis (Wlk.) were previously identified as (Z)-11-hexadecenal and (Z)-13-octadecenal. This paper describes field trials of the synthetic pheromones carried out in the Philippines, Korea and Iran during 1975 and 1976. These trials established that the two pheromones in their naturally occurring ratio are attractive to male C. suppressalis in the field. Both pheromones are necessary for efficient attraction, and ratios of the two pheromones close to the naturally occurring ratio are the most attractive. The rate of release of the pheromones was found to be critical in order to obtain an attractant source comparable with the virgin female moth. The bisulphite adducts of the pheromones showed some promise as a slow-release source of attractant material with a long field life. Preliminary experiments were carried out to assess the potential use of the two natural pheromones and of two pheromone “mimics”. (Z)-9-tetradecenyl formate and (Z)-11-hexadecenyl formate, as mating disruptants. All four compounds were shown to interfere with pheromonal communication between the sexes