The trap-oriented behaviour of tsetse flies (Glossinidae) and other Diptera

In field studies on Glossina morsitans morsitans Westw. and G. pallidipes Aust. in Zimbabwe, various traps baited with attractive odour were used to study the behaviour of flies in each of several stages of response to traps, from the stage of being several metres from the trap to the stage of being retained in a cage on the trap. The numbers of flies that were caught by electrocution, or were observed, as they moved forwards through the stages of trapping were compared with the numbers caught or observed moving in a reverse direction. A variety of stimuli and modifications were investigated for their effects on these movements, leading to provisional recommendations for improving the speed and efficiency of trapping. The most important recommendations were: the outside trap should be white, with black near the basal entrances, the entrances should be provided with tunnels projecting into trap, and the inside of trap should be made white at base and black at top. The top of the trap should be an open-ended tube around the cone of netting that leads to the retaining cage. Data for Stomoxyinae, non-biting Muscidae and Tabanidae are also presented.