Contact Sex Pheromone Research Articles

Stimulation of genital eversion in the land snail Helix aspersa by extracts of the glands of the dart apparatus

AbstractThe dart apparatus, used during courtship in some groups of hermaphroditic land snails, has long been assumed to have a “stimulatory” effect on the mating partner, though how stimulation occurs and exactly what function it serves has never been determined. In this study, extracts of the mucous glands of the dart apparatus of the land snail Helix aspersa were injected into conspecifics and into a related snail, Cepaea nemoralis, in order to test the hypothesis that the dart is used to achieve inflow of bioactive mucous gland secretions into the darted snail. Helix aspersa injected with the extract responded by everting their terminal genitals; eversion normally takes place during courtship and mating. Boiling the extract increased the bioactivity. Pronase‐treated extract lost bioactivity, and gel filtration of the boiled extract indicated that the active substance has a molecular weight of about 5,000. The active substance may be a polypeptide. Cepaea nemoralis also everted their genitals when injected with the boiled Helix extract. The active substance appears to be a contact sex pheromone, the second such pheromone in a pulmonate land snail for which experimental evidence has been obtained.

Synthesis of diastereomeric mixture of 15,19,23-trimethylheptatriacontane, contact sex pheromone of tsetse fly,Glossina morsitans morsitans westwood

A nine-step synthesis is described for a diastereomeric mixture of 15,19,23-trimethylheptatriacontane, a contact sex pheromone ofGlossina morsitans morsitans Westwood. The compound has been synthesized by means of double alkylation of diethyl 3-oxoglutarate (DEOG) with 3-methyl-2-heptadecenyl methanesulfonate, which was readily prepared from 1-hexadecene, as the key step.

Release of male courtship display in Periplaneta americana: evidence for female contact sex pheromone

Male American cockroaches ( Periplaneta americana) are attracted to virgin females by volatile sex pheromones. After antennal contact with the female they turn through 180° and spread their wings in courtship display. A chemical contact stimulus releasing male courtship is demonstrated in the female cuticle. Experiments with standardized olfactory stimulation by volatile sex pheromones revealed that the contact stimulus is sex-specific and species-specific. It can be washed off the cuticle with non-polar solvents and was successfully transferred to glass dummies. However, it is not effective in the absence of volatile sex pheromones. Thus volatile sex pheromones are responsible for male attraction and sexual motivation, while mate recognition is accomplished through the contact pheromone.

Search strategy of sex pheromone-stimulated male German cockroaches

Stimulation of the male German cockroach, Blattella germanica, with contact sex pheromone releases courtship behaviour and then area-restricted local search. Servosphere-recorded search patterns, compared to pre-stimulus pathways, are characterised by increased looping and path crossing and a relatively high rate of turning. Search behaviour can be performed in the absence of visual cues, including information relative to the site of stimulation. Information controlling search motor patterns is at least in part genetic; certain pattern components are generally similar from trial to trial, whereas specific pattern components vary widely.

The ecology of tsetse (Glossina spp.) (Diptera, Glossinidae): a review (1970–1981)

The literature published during 1970–1981 on tsetse ecology is reviewed. The geographical distribution of some species was affected during the drought of early 1970s. New maps of tsetse distribution in Africa and a few national maps have been published. The habitats of several species have been described in detail, particularly atypical habitats in peridomestic situations. Pupal ecology has not held the attention of ecologists so much; however, pupal duration and mortality have been assessed for a few species. Due to the importance of selective application of insecticides, resting sites and resting behaviour have been described in detail. Activity patterns have been correlated with climatic factors and also with sampling methods. Several works on host-seeking behaviour, flight performance and energy metabolism have been described. Host preferences of certain species have been found to be somewhat different from those previously recorded; and new host species have been discovered. Studies on fat and haematin content showed that these metabolites are useful indices of nutritional status to interpret feeding behaviour in relation to population sampling. A tsetse contact sex-pheromone has been discovered and synthetised; and attempts have been made to use it in the field. Studies on sound production by both sexes under various conditions of light and physiological state are in progress. Comparative studies on sampling techniques have received particular attention; several trap devices have been designed and tested to evaluate the reliability of samples. The determination of the age structure of populations has become more relevant to studies on population dynamics. Attempts have been made to calculate the growth rate of populations. Density-dependent factors started being taken into consideration in the assessment of populations. Several methods have been tried out to estimate population size. New pathogens, parasites and predators have been recorded.

Linyphid spider courtship: Releaser and attractant functions of a contact sex pheromone

Experiments with male bowl-and-doily spiders ( Frontinella communis) on methanol-washed and unwashed female webs indicate that the courtship of males is chemically released. Parallel experiments on the webs of females of another linyphiid species and on immature F. communis webs indicate that the releaser pheromone is species specific and that it is produced only by mature females. The pheromone that releases male courtship also functions as an attractant, changing the male's orientation from negatively to positively geotactic. The presence or absence of a female on the test web has only a slight effect on the male's behaviour.

Sex recognition pheromone in the tsetse fly Glossina pallidipes Austen.

Sexual responses of adult male G. pallidipes towards baited decoys show that a contact sex pheromone for this species is present in the hydrocarbon fraction of the adult female cuticle. Results are consistent with the view that the pheromone is a C35 compound and is present in sufficient quantity in newly emerged females to elicit maximum responses from males. Thus, maturation of sexual responsiveness is considered to be behavioral in females of this species.

The role of sex pheromones in initiation of copulatory behaviour by male tsetse flies, Glossina morsitans morsitans

ABSTRACT. Copulatory responses to a variety of decoy objects baited with synthetic 15,19,23‐trimethylheptatriacontane were induced in adult male Glossina morsitans morsitans Westw., provided the object was of similar shape and size to a female fly. Chemical and configurational (shape and texture) stimuli were important in eliciting and maintaining copulatory behaviour of males. A dose/response relationship was obtained from 7‐day‐old test males, with an ED95 of 2 μg using as decoys solvent‐washed dead males baited with 15,19,23‐trimethylheptatriacontane. The quantity of this compound in 5‐day‐old adult females is more than 4.0 μg; in males, only 0.6 μg. It is considered to have the characteristics of a true contact sex pheromone for the species, and does not act synergistically with other less stimulatory synthetic compounds. Gas chromatographic analysis of adult female cuticular paraffins of G.m.morsitans showed the presence of two large peaks between C37 and C38 which were virtually absent in males. Young adults of both sexes possessed a series of hydrocarbons below C29 which disappeared during the first few days of adult life. The natural pheromone appears on the pharate adult female about 2 days before emergence from the puparium and is present throughout life. This suggests it is a component of the surface cuticular waxes. Responsiveness of males to pheromone‐baited decoys increased to a maximum 3–4 days after emergence in regularly fed flies and only declined during the 24 h prior to death from starvation.

Specificity of contact sex pheromones in tsetse flies, Glossina spp.

ABSTRACT. Interspecific mating tests among seven tsetse species covering the ‘morsitans’ and ‘palpalis’ groups showed a degree of reaction that extends beyond the traditional taxonomic groupings. Tests with either live or dead females as targets produced essentially similar results which shows that differing responses of males are largely the consequence of differences in composition of the female surface cuticular paraffins and not of female behaviour. Gas chromatographic (GLC) analysis of cuticular paraffins tends to confirm this view. Responses of males of different species to dead conspecific males baited with the most active synthetic G.morsitans pheromone were variable. Comparison of behavioural responses and of GLC profiles of cuticular paraffins suggest that the species tested do not share a pheromone structure in common with G.morsitans. Mating tests with G.morsitans males using dead conspecific males baited with a variety of synthetic compounds provided evidence of the molecular configuration required to elicit a mating response. Synthetic 15,19‐dimethyltritriacontane induced a suboptimal response in male G.morsitans but is a likely candidate for a sex pheromone in G.austeni. Although not conclusive, a comparison of behavioural evidence and GLC data has permitted speculation on the nature of sex pheromones in tsetse of the ‘palpalis’ group.

Study on Chemosensitive Hairs in Wolf Spiders (Araneae, Lycosidae) by Scanning Electron Microscopy

The occurrence of chemosensitive hairs in some lycosid species is examined. The distribution and shape of such hairs dorsally on the male subadult palpal tarsus and the cymbium are compared. In certain species (e.g. of the genera. Pardosa and Alopecosa) the cymbium has a dense covering of these hairs while there are rather few of these in the male subadult palpal tarsus. The cymbium of Aulonia atbimana has comparatively few chemosensitive hairs dorsally, a condition supposedly related to the web‐building habit in this species. Indications are given that the cymbial chemosensitive hairs are involved in the detection of presumed contact sex pheromones produced by the female. Certain intergeneric differences in the shape of the apical part of the cymbial chemosensitive hairs are noted.

Factors involved in the responses of male german cockroaches to synthetic sex pheromone

The precopulatory response of male German cockroaches,Blattella germanica, to synthetic contact sex pheromone (compound A) and analoge I increases with concentration, is greatest during the dark phase of the photocycle, and is enhanced by isolation of males from females of this species.

The contact sex pheromone of Pardosa lapidicina Emerton (Araneida: Lycosidae)

Laboratory bioassays of male courtship behavior in Pardosa lapidicina indicate that the contact sex pheromone is associated with the silk dragline deposited on the substratum by mature females. The pheromone is quickly inactivated by water. It appears to represent a facultative sexual stimulus, and can be by-passed if the male first touches the female.

Eléments du comportement sexuel chez Pardosa xerampelina (Keyserling) (Araneida : Lycosidae)

Courtship in male Pardosa xerampelina is stimulated by a contact sex pheromone laid down by the female, though visual cues also play a part. There is a short period of immobility, followed by the extension and raising of the pedipalps, one after the other. The male then makes a short run toward the female, his tarsi making an audible sound on the substratum. This sequence is repeated one or more times until the male is very close to the female, when he drums on the substratum (also producing a sound), taps the legs and cephalothorax of the female with his anterior legs, and mounts at once.