Published online by Cambridge University Press: 10 July 2009
Investigations, using tantalum-182, into the behaviour of Glossina morsitans Westw. in large field cages are described. Individual straight-line displacements occurred on average about every three hours and were generally small and erratic in direction. The perimeters of the cages tended to ‘ trap ’ an enclosed population, but flies appeared to move to the walls more quickly when they were shaded by an outer covering of hessian. Horizontal distribution and movements of flies did not appear to be associated directly with the enclosed vegetation, artificial roosting sites or host animals. Observations on vertical displacements indicated diurnal movements to and from boles of trees and changes in roosting heights. The majority of flies rested between six and ten feet above the ground, though individuals were seen from ground level to 30 ft. Few observations were done at night, but two flies were seen on the underside of leaves.