The influence of sublethal doses of insecticides on the reproduction of glossina-pallidipes austen and glossina morsitans morsitans westwood (Diptera: Glossinidae)

Abstract

Insecticides utilised in the field to control tsetse flies often do not reach their targets in sufficient quantities to kill them. The effects of such sublethal doses on the reproduction of these flies is therefore important in assessing fly populations after spray applications. Various concentrations of deltamethrin and the natural pyrethrum extract from 10-14 to 15 nanograms per micro liter (ng/ul) of the insecticides in redistilled acetone were topically applied (1 ul/fly) on the dorsal thorax of wild caught Glossina pallidipes Austen and laboratory reared Glossina morsitallS morsitans Westwood females 24 hours after they took a blood meal. Flies were also hand held on insecticide treated glass and cloth surfaces to allow transfer of the chemicals. Treated and control flies were maintained and fed daily until death.