A trio of instruments for tsetse control
3) A harmonious approach

What is it about a warthog that makes it so attractive to tsetse and yet waterbuck and zebra remain free of the effects of tsetse and the trypanosomes they carry? The answer, according to Rajinder Saini of ICIPE (the International Centre for Insect Physiology and Ecology, Kenya), is an odorous one: warthogs have a smell that attracts or 'pulls' tsetse to them whereas the smell of a waterbuck repels or 'pushes' tsetse away. Although cattle are also highly attractive to tsetse, it has been known for some time that cattle urine contains one compound, methoxyphenyl, which is mildly repellent. This has been used by ICIPE to develop a synthetic repellent, which effectively prevents tsetse from smelling the cattle when hung in a dispenser on a collar around the animal's neck.

credit: Rajinder Saini, ICIPE

Trials have been conducted on herds in Nguruman in south-western Kenya with pastoralist herds and results have shown that with only 50 to 75 per cent of the animals wearing collars, over 95 per cent of the infection occurs in unprotected animals. Although the compound is only currently available in minute quantities, which makes it very expensive, an agreement has already been signed with an Italian pharmaceutical company to start mass-production. For pastoralists, who currently rely on trypanocidal drugs for trypanosomiasis control, it is an alternative option, which can be used alone to push tsetse away. For more sedentary communities, the use of the collar ('push') could also be combined with a 'pull' technology, that is cattle treated with pour-ons or with traps/targets in the area where protected cattle are grazing ('pull and kill').

For more information:
ICIPE