Why do tsetse follow my car?

Tsetse have evolved a range of mechanisms for finding their hosts. At one extreme, they simply 'sit and wait' for a host to pass while the other is to hunt actively for the host. Most of the flies arriving at a trap or target were probably actively hunting for a host. Flies attracted to moving objects, such as a moving car, are probably tsetse that were sitting and waiting for a host to pass (Vale, 1974; Hargrove, 1991).

We can take advantage of this response by using various mobile baits to survey for tsetse. These mobile baits include:-

• a human fly-round, where one or two people walk through the bush and catch any flies that land on them
• an ox fly-round, where the people catch tsetse as they land on an ox
• a mobile electric net, where tsetse are caught by an electric net mounted on the back of a Land Rover

These methods are particularly effective for the various subspecies of G. morsitans (e.g. Vale, 1974) and young and/or recently-fed tsetse in general (Vale, 1974; Hargrove, 1991). However, they are technically and/or logistically demanding and in most cases it is probably easier and more effective to use odour-baited traps, even for G. morsitans.