Evidence for a discrete evolutionary lineage within Equatorial Guinea suggests that the tsetse fly Glossina palpalis palpalis exists as a species complex

Tsetse flies of the palpalis group are major vectors of Human African Trypanosomiasis in Africa. Accurate knowledge of species identity is essential for vector control. Here we combine ribosomal internal transcribed spacer 1 (ITS1), mitochondrial Cytochrome Oxidase 1 (COI) and microsatellites to determine the population structure and phylogenetic relations of G. p. palpalis in Equatorial Guinea. COI sequence data suggest that G. p. palpalis in Equatorial Guinea are a distinct subspecies from previously described G. p. palpalis in West Africa and Democratic Republic of Congo. G. p. palpalis in Equatorial Guinea and DRC share a common ancestor which diverged from West African G. p. palpalis around 1.9 million years ago. Previous ITS1 length polymorphism data suggested the possible presence of hybrids in Equatorial Guinea. However, ITS1 showed incomplete lineage sorting compared to clearly defined COI groups, and data from twelve unlinked microsatellites provided no evidence of hybridizati...