Radiolsotopes as metabolic labels forGlossina(Diptera: Glossinidae). II. The excretion of137Cs under field conditions as a means of estimating energy utilisation, activity and temperature regulation

Abstract

Males ofGlossina morsitansWestw. andG. pallidipesAust. labelled with radiocaesium (¹³⁷Cs) were released in their natural habitat and later recovered on four occasions in the hot, hot wet and cold dry seasons in Rhodesia. The rate of excretion of the radioisotope was related to previous laboratory results to give estimates of activity, temperature regulation and energy utilisation in the field. It is considered that maleG. morsitansare unlikely to fly for more than a few minutes per day. The hunger cycle duration is estimated as 3·5–4 days forG. morsitansmales and 5·5 days forG. pallidipesmales. Temperature regulation within the range 23–27°C was exhibited by both species, especially in the winter.