Biological Control of Tsetse fly Project (BICOT) in Lafia Local Govenrment Area of Nasarawa State, Nigeria, 1984 – 2000.

摘要

In 1980 the Federal Department of Livestock and Pest Control Services through the biological control of tsetse fly project (BICOT) was actively involved in tsetse fly control eradication using a combination of tsetse population reduction and sterile inset technique (SIT). The project area covered approximately 1,500sq. Km of land and lay within the Lafia local government Area (LGA) of Nasarawa State. The area was virtually freed of Glossina palpalis palpalis, and to some extent G. tachinoides by December 1984. By 1987, however sterile male releases were suspended, and remained so until now due to lack of funding. In order to ascertain the present situation in the area as a way of estimating how long such a cleared area could remain free of tsetse before reinvasion, the present study was conducted; this being 16 years after the eradication of G.p palpalis and removal of over 90% of G. tachinoides, which sell the main tsetse species in the area. At least 10 biconical traps were set at an interval of about 250 meters along each river/stream in the study area. Captured flies were dissected to identify those, which are positive for trypanosomes. In all, 466 tsetse flies were caught out of which 454 were G.p. palpalis while the remaining 12 were G. tachinoides. The result of dissection showed that 9(1.9%) of the total flies caught were positive for trypanosomes with all being T.vivax. IAll infected flies were G.p. palpalis. The small number of G. tachinoides caught could be responsible for the absence of infection in this species during the study period. Introduction Tsetse transmitted trypanosomosis is classified as severe in the majority of the 37 sub-Saharan countries affected where it figures among the first three priority veterinary diseases (FAO, 1992). Animal trypanosomosis and tsetse flies (Glossina) are widely distributed in Nigeria from latitude 4 0 N to 13 0 N, an area covering all the five-agro ecological zones of the Country (Onyiah, 1997). African animal trypanosomosis has also been described as one of the most important livestock diseases endemic to the African continent, and a major factor constraining livestock production in Nigeria (Ikede, 1989 and Urquhart, 1974). The key characteristics of trypanosomosis infection are the presence of trypanosomes in the blood and anaemia, caused by the destruction of red blood cells induced by the parasites. Previous studies have shown that the key indicators of trypanotolerance are the abilities to limit the number of parasites in the blood (parasitaemia control) and maintain relatively normal levels of red blood cells (anemia control) when infected (Anon, 1991).According to Anon (1991), previous work in the African Trypanotolerant livestock Network has shown that the degree of anaemia in trypanosome–infected cattle, as measured by the packed red cell volume (PCV) in the blood, is correlated with such production traits as reproductive performance and growth. Animals able to maintain high PCV levels are more productive than those with lower PCV values. The report further stated that in 1989, studies have demonstrated that an animal’s ability to maintain high PCV levels when infected with trypanosomes is a heritable trait. In 1980, the Federal Department of Livestock and Pest Control Services through the biological control of tsetse fly project (BICOT) was actively involved in the control/eradication of tsetse flies. The project was situated in Lafia Local Government Area of Nasarawa State because of the huge agricultural (especially livestock) potentials in the area. Before the establishment of the project, the full utilization of livestock potentials was greatly affected by tsetse flies. Biological control is the use of living creatures or organisms such as parasites and predators, to control or eradicate other creatures, which are harmful (Davies, 1977). The most important parasites of tsetse are those that attack the pupae and the main ones are small flies e.g. Mutilla glossin