The effect of environment and host type on the rate of digestion in the tsetse fly Glossina morsitans Westw

Abstract

The rate of digestion, as reflected in the rate of excretion, on a blood-meal was measured in males of Glossina morsitans Westw. (subsp. orientalis Vanderplank) under identical conditions of temperature and relative humidity but varuing conditions of other factors. The rates of excretion in non-teneral males captured after feeding on bait-oxen in two different habitants were identical and were significantly higher than those of non-teneral field-collected males fed on guineapig in the laboratory. The latter excreated the meal more rapidly than non-teneral males that emerged and were fed on guinea-pig in the labortory. That the variations were not due differences in blood type was shown by feeding teneral laboratory-emerged males on different hosts; the rates of excretion of meals from different mammals did not significantly one from another. Teneral laboratory-emerged flies excreted more rapidly when fed on reptilian or avian blood than when fed on mammalian. The lower rate of excertion in laboratory explanations in terms of a metabolic uncoupliing and pre-feeding behaviour are described.