Do targets have any bad environmental effects?

The shape and colour of targets and the blend of tsetse attractants are specifically designed to attract tsetse flies. Some of these features attract other biting flies: the phenols attract some species of horsefly (Phelps & Holloway, 1992), octenol attracts some species of stable fly (Holloway & Phelps, 1991) and both horseflies and stable flies are attracted to blue or black targets. However, even populations of these species are not greatly reduced by targets (Vale et al., 1988). The slow rate at which tsetse reproduce means that only they are susceptible to the relatively small mortality (<10%/day) produced by insecticide-treated targets (Hargrove, 1988).

Some of the activities associated with deploying targets can have detrimental effects. For instance, in large scale operations conducted in unsettled areas, government veterinary departments will often construct access roads. These roads can promote uncontrolled hunting of wild animals and settlement. However, these effects do not generally occur in small-scale schemes conducted by local people.