New field methods for studying the responses of tsetse flies (Diptera, Glossinidae) to hosts

Abstract

Field studies with Glossina morsitans morsitans Westw. in Rhodesia showed that hand-net catches can reduce slightly the responses of males to mobile baits and can reduce female responses by three-quarters. Description is given of methods of operating baits in the absence of men and of methods of electrocuting flies as they fly near baits, alight on baits and respond to decoy tsetse. These techniques are more efficient and objective than hand-net catching.

Olfaction in vector-host interactions

“…Two technical developments were particularly important for this. First, electric nets (Vale 1974a) provided an objective method for assessing the numbers of tsetse in the vicinity of moving or stationary hosts. Second, the use of ventilated pits (Vale 1974b) provided a means of producing natural host odour with or without any associated visual stimulus.…”

Olfactory responses of Glossina fuscipes fuscipes (Diptera: Glossinidae) to the monitor lizard Varanus niloticus niloticus

“…Tsetse were caught with biconical traps (Challier et al, 1977), 1-m 2 electric nets (Vale, 1974a;Bonar Industries, Zimbabwe) or electrified pipe models constructed locally. The electrified model consisted of a PVC pipe 150 cm long and 10 cm in diameter similar in proportion to an average-sized monitor lizard ( fig.…”

“…An electrified pipe model, simulating the shape and size of a monitor lizard, was used as a visual target (see Vale, 1974a). Two experiments were performed over eight days inside the forest using four models, with the following baits: 1) a fresh live monitor lizard (c. 3 kg) confined inside the model; 2) lizard urine placed inside the model (release rate c. 500 mg/h), 3) hippopotamus dung (c. 2 kg); and 4) control ( = empty model).…”

Analysis of the components of ‘electric nets’ that affect their sampling efficiency for tsetse flies (Diptera: Glossinidae)

“…), first described by Vale in 1974, are now standard techniques used throughout Africa (see Vale, 1993 et ante). Vale (1974) originally estimated the efficiency of electric nets as 96 -99%, inferring that they were effectively invisible to the tsetse, and therefore sampled completely objectively.…”