The diversity of tsetse flies in Chegere Sub County in Apac District, Nothern Uganda

Abstract

It is widely known that tsetse flies are solely responsible for the cyclical transmission of trypanosomes, the causative agents of ‘sleeping sickness’ in humans and ‘nagana’ in livestock. There are 31 species and subspecies of tsetse flies, which are divided into three distinct groups by their habitats: Morsitans in savannah regions, Palpalis in high humidity areas and Fusca in evergreen forests. The purpose of the present study was to determine the diversity of tsetse fly species in Chegere Sub County, given a wide wetland with patches of forest in it which tsetse flies take advantage of and use as their feeding and breeding ground. Nine villages from three parishes; Chegere, Kidilani, and Atigolwok in Chegere sub county were sampled. Pyramidal traps baited with natural odours of fermented cattle urine were used to collect tsetse flies from August to September 2024 for a duration of four weeks covering only the wet season. The identification of the tsetse species was based on observation of the morphological characteristics like antennal fringe, scutellum, body size, and hind leg among others, using a hand lens and stereoscopic dissecting microscope. Data on the abundance of tsetse fly species were analyzed using the Kruskall-Wallis test at α = 0.05 to compare the variation in the abundance of tsetse flies in the different sampling areas. All statistical analysis was done using IBM SPSS V20. Graphical representations were done using Graphpad prism V8.0.2. A total of 233 tsetse fly specimens belonging to one species, Glossina fuscipes, were recorded. The parish with the highest relative abundance of tsetse flies was Chegere (0.747) followed by Atigolwok (0.245) while Kidilani parish had the least relative abundance of tsetse flies (0.009). The swampy vegetation where tsetse flies were widely distributed showed up across two parishes (Chegere and Atigolwok). Statistically, there was a significant variation in the abundance of tsetse flies at α=0.05 in the three parishes sampled (Kruskal-Wallis chi-squared = 14.263, df = 2, p-value = 0.0007995. The findings presented show that tsetse fly abundance is strongly affected by the habitat suitability. This is why their abundance were different in the different biotopes of the three parishes in Chegere Sub County. Emphasis should be made regarding high tsetse fly density, being monitored closely for signs of trypanosomiasis, especially in regions where livestock farming is prevalent and Chegere Sub County is not exclusive. Despite the worth of the present findings, there is still need for a study elaborating the association between host abundance and tsetse fly abundance in Chegere Sub County