Factors defining the distribution limit of tsetse infestation and the implication for livestock sector in Tanzania

Abstract

Tsetse survey to re-define its distribution limit in Tanzania was conducted from 2005 to 2009. Based on the old tsetse infestation map, tsetse sampling using odour baited biconical traps were deployed and emptied after 24 h during the onset of dry season. The survey covered the southern, western, northern and north eastern regions of the country. Obtained results indicated that Glossina morsitans sl and G. pallidipes were the dominant and widely distributed tsetse species, although their boundaries had shrank. Changes in land use, which include human settlement and associated activities, infrastructure development and land reform policies, were the major reason for the new tsetse distribution limit. Movement and settlement of huge stocks of insecticide baited livestock in once tsetse infested areas significantly altered the ecology of favored tsetse habitats and their hosts leading to the disappearance of tsetse breeding sites and tsetse species. Human population increase in formally tsetse infested areas also contributed to the disappearance of tsetse. The most affected regions were found to be Rukwa and Mtwara. Chi square test indicated a significant difference on number of collected tsetse in different location; highest density observed in game reserve and the lower in areas near wild animal migratory corridor and protected forest areas. Tsetse flies were confined to protected areas, which include national parks, game and forest reserves. The new tsetse distribution limit is set to influence the epidemiology of African Trypanosomiasis, tsetse control initiatives and the future of livestock sector in Tanzania. Key words: Tsetse ecology, African trypanosomiasis, land use, conserved areas, livestock.