Effects of Glossina morsitans morsitans Westwood (Diptera: Glossinidae) sex Pheromone on behaviour of males in field and laboratory

Abstract

More adult males of Glossina morsitans morsitans Westw. were caught with hand nets in Tanzania from a man-carried dark screen baited with surrogate female decoys impregnated with synthetic 15,19,23-trimethylheptatriacontane (the G. m. morsitans sex pheromone) than from a screen bearing unimpregnated decoys or from a screen alone. A similar pattern was obtained with G. pallidipes Aust., but the variations in numbers of both species caught within and between fly-round sectors were large. Although many G. m. morsitans males attracted to the screens visually were seen to engage in copulatory activity with pheromone-impregnated decoys, none of the G. pallidipes so attracted was seen to do so. It is therefore concluded that catches of G. m. morsitans were not improved by the presence of pheromone-baited decoys on visually attractive screens. Copulatory behaviour was frequently interrupted by other flies and/or the flies flew off as soon as the screen ceased to move. Of the G. m. morsitans males attracted to a baited screen on the back of a slowly moving vehicle, 51 % were seen to have alighted on the impregnated decoys and 42% were engaged in copulatory behaviour with the decoys immediately after the vehicle stopped. Copulatory responses of wild male G. m. morsitans to pheromone-impregnated decoys in glass tubes approximated those of laboratory-reared males only after confinement for several hours at low light intensity. Contamination of laboratory-reared male G. m. morsitans with synthetic pheromone elicited prolonged male:male copulatory behaviour. Prospects for the use of the G. m. morsitans sex pheromone in population studies or control programmes are discussed.

Classification of tsetse flies Glossina spp. (Diptera: Glossinidae) by gas chromatographic analysis of cuticular components

“…The cuticular hydrocarbon profiles of several taxa of Glossina were obtained using GC (Huyton et ah, 1980b;Carlson, 1981Carlson, , 1982Carlson, , 1988 during sex stimulant pheromone studies in a few species (Langley et al, 1981;Carlson et ah, 1984). Traditional phylogenetic relation-ships were supported in preliminary observations of GC profiles of 10 well studied species (Carlson, 1981).…”

Prospects for autosterilisation of tsetse flies, Glossina spp. (Diptera: Glossinidae), using sex pheromone and bisazir in the field

“…Initial experiments in Tanzania showed that wild males of G. m. morsitans visually attracted to a dark screen attempted to copulate with small objects on the screen if the objects were baited with sex pheromone (Langley et al, 1981). The duration of attempted copulation with these objects in the field was short by comparison with that measured in the laboratory and was influenced by the movement of the screen and probably by the presence of man in the experimental situation (Langley et al, 1981).…”

“…Initial experiments in Tanzania showed that wild males of G. m. morsitans visually attracted to a dark screen attempted to copulate with small objects on the screen if the objects were baited with sex pheromone (Langley et al, 1981). The duration of attempted copulation with these objects in the field was short by comparison with that measured in the laboratory and was influenced by the movement of the screen and probably by the presence of man in the experimental situation (Langley et al, 1981). There is a complex interaction between the visual and olfactory stimuli associated with a variety of baits in the form of mobile or stationary inanimate models, men or host animals, and the sex and species composition of tsetse attracted to them (Vale, 1974a).…”

Flying mate detection and chasing by tsetse flies (Glossina)

“…Male Diptera commonly chase and accost prospective mates in flight (Land & Collett, 1974;Collett & Land, 1975;Wehrhahn, 1979;Gibson, 1985), a facet of their behaviour that has attracted attention because of the potential it provides for analysing the mechanisms and precision of vision and visually controlled behaviour. Tsetse fly males are likewise attracted to female-sized targets (Vale, 1974;Langley et al, 1981;Hall, 1987), but the visual aspects of this behaviour have been examined only in Correspondence: Dr J. Brady, Imperial College, Silwood Park, Ascot, Berks. SL5 7PY. relation to attracting males to immobile dummy female 'baits' (see Hall, 1987;Wall, 1989).…”