Feeding responses of tsetse flies (Diptera: Glossinidae) to stationary hosts

Abstract

An incomplete ring of electrocuting nets was placed round various mammals stationed singly in woodland infested with Glossina morsitans morsitans Westw. and G. pallidipes Aust. in the Zambezi Valley in Rhodesia. Catches of fed and unfed flies made on the inside and outside faces of the nets were used to estimate the number and nutritional status of flies travelling to and from the baits. The validity of these assessments was investigated by studying the responses of the flies to the netting frame, and the effects of different heights and arrangements of nets. The percentages of recently fed flies in samples leaving various mammals were: ox 33–61, donkey 51, sedated ox 42, kudu 41, washed ox 34, warthog 19, sedated goat 15, ox with three men 12, bushpig 8, buffalo 5, ox sprayed with repellent 4, bushbuck 2, goat 1, sheep 1, impala 0. With the ox, the proportion of fed flies fell by one-third when the number of tsetse attracted to the ox increased 4·5-fold to the point where the ox became intolerant. Effects of time of day and season on the proportion of flies feeding are discussed.