The Influence of Temporal and Seasonal Changes on Genetic Diversity and Population Structure of Thee Tsetse Fly, Glossina Pallidipes in Kenya

Abstract

The Tsetse fly. Glossina pallidipes. (Diptera: Glossinidae) is an important vector of animal trypanosomiasis It has also been implicated in the transmission of pathogens that cause human AfricanTrypanosomiasis. Understanding how C. pallidipes populations vary temporally is necessary for effective intervention. Temporal variation in allele frequencies at eight microsatellite loci was assessed by sampling local populations of C. pallidipes. Samplings were carried out in 2000, 200 I, and 2003 in the Lambwe Valley and Nguruman areas in Kenya. Six polymorphic loci were scored. ABele frequencies were homogenous between seasons. Genetic differentiation was higher among dry season samples (F, r = 0.051, C" = 0.047) than wetseason samples (F" = 0.041, C" = 0.037). Differentiation between pooled dry season and pooled wet season samples did not differ (F; r = 0.008, C" = 0.004). Analysis of variance revealed no substantial genetic subdivision in seasons or years. It is concluded that C. pallidipes populations are more aggregated during the dry season, resulting in stronger measures of genetic differentiation when compared with wet seasons. However, season and time had no effect, indicating relative stability of C. pallidipes populations. Thus, strategies for suppression of G. pallidipes in the country should adopt measures that may not reduce effectiveness in different times of the year.