Observations on the ecology and trypanosome infections of a relict population of glossina medicorum austen in the komoe valley of upper volta

Information is presented on the distribution, ecology and trypanosome infections of a relict population of Glossina Medicorum in the Northern Guinea Savannah vegetation zone of south-western Upper Volta, during the 1976/77 late dry season. G. medicorum was readily captured in white Challier and Laveissièere (1973) tsetse traps and surveys with these traps showed the species to be distributed between 9° 42° and 10° 1′N in the lower River Komoe valley. This is the most northerly location of this species so far known. G. medicorum was widely distributed in the fringing forests of the River Komoe, although the most popular habitats were in situations where the typical fringing forests were backed by relatively extensive areas of Guibourtia copallifera forests and where wildlife was abundant. In such areas, flies were most active during the dusk-dawn period. The overall trypanosome infection rate of G. medicorum was 29·4%, which is thought to be the highest so far recorded for the species. Trypanosomes found were attributed to the Duttonella subgenus (64·3%) and the Nannomcmas subgenus (35·7%). No salivary gland infections were found. Some brief ecological observations on G. tachinoides, G. palpalis, and G. morsitans which co-existed with the G. medicorum populations studies, are also described.