The causes of mating abstention in male tsetse flies Glossina morsitans

Abstract

ABSTRACT. The sexual response of a Glossina morsitans morsitans Westw. male towards a decoy consisting of a dead male dosed with synthetic sex pheromone, was depressed by the presence of the cuticular lipids of the decoy male. However, addition of a C24 paraffin, not normally found on or in the cuticle of male or female G.m.morsitans, to a decoy male from which cuticular lipids were removed had a similar effect. Addition of either the C24 paraffin or an extract of male cuticular lipids to decoy females which possess natural sex pheromone in their cuticles, again depressed the sexual responses of males towards the decoys. The n‐hexane solvent used in the application of compounds to decoys, itself depressed responses towards natural pheromone on a dead female at volumes in excess of 100μl, presumably because it mixed the surface waxes which masked the pheromone. Occlusion experiments implied that sex pheromone receptors are present on both the tarsi and tibiae of the male. No evidence was found for the existence of a specific mating deterrent on or in the cuticle of male G.m. morsitans.