A Survey Method of Trypanosome Infections in Glossina

Abstract

THE incidence of trypanosome infections in wild populations of tsetse flies (Glossina morsitans West (Muscidae: Diptera)), varies from one locality to another, and seasonal changes also occur. The method hitherto used to determine infection-rates has been the dissection of samples of live flies as described by Lloyd and Johnson¹. This has the disadvantage of requiring the establishment of a team of microscopists in the bush, so that examination of simultaneously collected samples over wide areas is difficult. The recognition of trypanosomes in the mouthparts of preserved wild Glossina is not possible because regurgitation of stomach contents, which may occur when the insect is placed alive in the preservative, renders many of them opaque.