Pupal Ecology And Role Of Predators And Parasitoids In Natural Population Regulation Of Glossina Pallidipes Austen (Diptera : Glossinidae) At Nguruman, Kenya.

CHAPTER ONE

 1. GENERAL INTRODUCTION

1.1 THE SCOURGE OF TSETSE

All tsetse flies belong to the order Diptera and the genus Glossina. This genus was formerly included in the family Muscidae (Newstead, 1911; Newstead et £l_., 1924; Patton, 1934; Iimts, 1957), but has in recent times been placed in the monogeneric family, Glossinidae (Brues etal_, 1954; Haeselbarth et aj_, 1966; Potts, 1970a). The genus is made up of 30 species and subspecies which are divided into three principal groups, namely, fusca (the forest tsetse), pa 1 pa 1is (the riverine tsetse) and morsitans (the savanna tsetse), (Jordan, 1974). The scourge of tsetse flies and trypanosomiasis is one of the major factors inhibiting agricultural advancement in over 40% of the African continent (Buxton, 1955; Glasgow, 1S63; Ford, 1965; Ford and Katondo, 1977; Langley, 1983). The disease not only constitutes a serious human health hazard, but also imposes a major constraint on general agricultural development, human settlement and livestock 2 production. Breeding of livestock in 7 million km of the affected 13 2 million km area is impossible due to high incidence cf the disease which extends from 14°N to 29°S with either continuous or isolated areas of infestation (Ford, 1970; FAO, 1974; Pant et al_., 1977). The most obvious effect of animal trypanosomiasis is enormous losses in livestock which lead to shortage of natural fertilizer for crop production, and shortage of dairy products and animal protein resulting in malnutrition. Human sleeping sickness poses a serious health problem to over 20 million people. This potentially fatal disease affects about University of Ghana http://ugspace.ug.edu.gh 10,000 people each year (FAO, 1974), and it results in poor health and low industrial and agricultural output. It also causes depopulation by death or by migration of people from tsetse-infected areas resulting in large areas being relinquished to tsetse flies and wild animals (Ford, 1971). The endemicity of the disease is due to the fact that some game animals and also domestic animals, particularly pigs, are reservoirs of the causative organisms called trypanosomes. Four of the six main Trypanosoma species of socio-economic importance infect livestock and have a wild animal reservoir. These are T. vivax Ziemann, J. brucei Pliimer and Bradford, 2- simiae Brues et aJL and 2- congolense Brcden. The remaining two species, 2* rhodesiense Stephens and Fantham and 2- gambiense Dutton are zoonoses with infection in livestock and game and acute clinical infection in man. 2 - rhodesiense is found in specific foci in East Africa, while 2- gambiense is mainly restricted to West and Central Africa (Maclennan, 1975).