Studies on the Bio-Ecology and Taxonomy of Glossina with Particular Reference to Glossina Fuscipes Fuscipes (Newstead)

Abstract

This thesis reports studies on three aspects of Glossina biology:- a) Studies on the peridomestic behaviour of Glossina fuscipes fuscipes in the sleeping sickness epidemic focus of Busoga, Uganda. b) Application of analysis of cuticular hydrocarbons in the chemotaxonomy of Glossina and c) Studies on the ovulation and late mating of virgin Glossina. A search near homesteads, made over a period of 20 months, revealed tsetse puparia and puparial shells under Coffea canephora (coffee), Musa sp. (banana) and Lantana camara thickets, under house verandahs and, once, inside a hut. Studies on the peridomestic resting sites were carried out both at night and during the day. Flies were caught, marked with fluorescent powders and then released in coffee and banana plantations, Lantana camara thicket and adjoining forest habitat and potential resting sites subsequently searched. Leaves, twigs and branches between 0.5 and 1 cm in diameter were found to be preferred resting sites. The resting heights ranged from O to 3.66 m. The breeding and resting sites of G. f. fuscipes in the peridomestic habitat are described for the first time. The implication of these findings in relation to the transmission and control of the current epidemic of sleeping sickness in Busoga is discussed. Analyses of the cuticular hydrocarbons of members of the fusca group, allopatric populations of G. pallidipe: different age groups of G. f. fuscipes and puparial she: of G. f. fuscioes and G. p. gambiensis were carried out using Gas Liquid Chromatography. Discriminant analysis used to analyse the data obtained. Significant different in hydrocarbon composition were found between members of the fusca group and allopatric populations of G. pallidipes. The technique was also able to separate age groups of G. f. fuscipes and to identify puparia. The prospects for using this technique as a tool to age tsetse and to identify puparia found in the field are discussed Ovulation and late mating have been studied in virg G. f. fuscipes, G. p. gambiensis, G. tachinoides and G. m. morsitans. In most cases ovulation took place normally but in some flies eggs were found piled up in uterus and ovary. These eggs were either eventually e xtruded from the uterus or their egg yolk degenerated the empty chorions were extruded. One fly extruded a premature second instar larva which was well developed, with a tracheal system and segments. Late mated flies d not larviposit and. the significance of multiple mating the field is discussed. These studies provide a basis further investigation of abnormalities in virgin female in relation to parthenogenesis and late mating.