Tsetse research and control

Initial large-scale initiatives to control the tsetse flies began in 1910. Over time, more radical methods were used, including the destruction of tsetse habitats through bush clearing and extermination of wildlife. Due to limited labor capacity, bush clearing was not a permanent solution—the vegetation regenerated and the flies returned.48 In the German East African territory of Tanganyika, the demographic changes were followed by major transformation of the natural vegetation—the open grasslands were trans- formed into bushlands49 that were utilized by the flies which increased their geographical distribution.’0 Although the threats to people and cattle required emergency action in which time was of the essence, ecological studies that linked the distribution of tsetse with wild ungulates required complex experiments.51 Methods of control that might have worked for one species did not necessarily work for others. This may be partly explained by the different species of tsetse that required different ecological conditions and types of hosts. It had become clear that different species of tsetse flies were responsible for different strains of trypanosomiasis. In the Speke Gulf of Mwanza on the Tanganyika side of Lake Victoria, the sleep- ing sickness outbreak was linked to the prevalence of Qlossina rhodesience. Thus, decimation of elephant populations in central Uganda were aimed at controlling the spread of the fly.’2 In 1925, the spread of Qlossina morsitaas in Uganda was attributed to the recovery of wildlife after the earlier destruction attempts.’5

Nevertheless, the main failing of imperial science research was to seek solutions before investigating the problems. In this regard, experimental trials were not distinguished from practical land reclamations.’4 Scientific research approaches showed a preference for regional research centers and subsidiary research stations across the three colonies. The first regional research center was established at Shinyanga in Tanganyika in about 1918. It coordinated the activities of an interdisciplinary research team.” Medical research on the epidemiology of the trypanosome did not begin until 1919, due to a lack of funds and specialized research personnel. By 1922, attempts were being made to secure more funds for large-scale experimental attacks on the tsetse.’6 Consequently, in 1923, a labor force of 10,000 was organized to clear a barrier ‘in front of the fly advance,’ in order to separate the tsetse-infested areas from the settled areas.’7 Species prevalence, the types of vegetation cover and climatic conditions were investigated.’8

During early ecological research activities, land reclamation was marked by both optimism and inadequate practices. The optimism was due to the fact that ecological research in Africa was a new field of investigation, offering experienced researchers, opportunities to test new scientific theories and methods. However, inadequacy was evident in that the researchers were not trained in tropical ecology, which forced them to rely on methods developed in Europe to solve African medical and environmental problems.’9 One imaginative method attempted was conducting a census of the flies by using ‘fly boys’—mainly local African men trained to catch the flies (by attracting them to themselves). Later, the human objects were replaced by dark clothes.60 However, according to the first director of the Tsetse Fly

Research Center (C.F.M. Swynnerton, after whom Q. wynnertoni was named), tsetse control is complex, involving a vicious cycle of attack and retreat. In his opinion, bush clearing alone, without determining how the people and livestock would be isolated from the fly, would not produce the desired results.61 In other words, no method was sufficiently robust to stop the expansion of the flies.

The tsetse research and control efforts had raised two questions that needed to be examined. First, is it possible for experimental treatment alone to wipe out tsetse flies and consequently sleeping sickness, or could medical treatment control the disease (if not future infection)? Second, would land reclamation and resettlement solve the problem of tsetse expansion?62 The emphasis of further action was on the practical application of research findings. In 1928, the Tsetse Committee of Civil Research embarked on the first ever systematic experimental work in the field, stimulating scientific research interests on the questions of human health and the economic impacts of tsetse fly control. There was, however, a major shift in tsetse research and control activities when the Department of Tsetse Research was established in 1929 by means of a five-year research grant from the East African Loan Scheme.6' The tsetse research combined ecological and entomological investigations with bush clearing. It was still apparent that tsetse flies would be difficult to eliminate unless their contact with wildlife and domesticated stocks was broken.64 By the 1930s, the dilemma for the colonial officials was balancing tsetse fly research with other development initiatives—in particular, soil erosion control.65

 
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