Studies on the infection rates of a West African stock of Trypanosoma vivax in Glossina morsitans morsitans and G. m. centralis

Abstract

Investigations were conducted on the infection rates of a West African stock of Trypanosoma vivax in Glossina morsitans morsitans and G. m. centralis. The mature infection rate, as revealed by the warm-slide probe, was only 9·4% in contrast to 67·7% by the dissection method. The infection rates determined by the latter technique varied between 46·;7 and 100%, and there were no significant differences in the rates between tenerals and non-tenerals, males and females, the two sub-species, the different age of the vectors or the different peaks of parasitaemia in the goats at the time of the infective meal. In some tsetse the number of parasites in the hypopharynx was markedly high, and there was no significant difference in the frequency of such vectors between the sexes. The mean infection rates in G. m. morsitans increased with increase of the parasitaemia in the host goats. The overall results are discussed in terms of the field situation.