The field responses of tsetse flies, Glossinaspp. (Diptera: Glossinidae), to odours of host residues

Abstract

In Zimbabwe, the catches of Glossina pallidipes Austen and G. morsitans morsitans Westwood in traps were roughly doubled by the presence of two bushpig bedding sacks or jars containing 200 ml of urine from ox or buffalo. The main effect of these residues was to increase the trap-entering responses of tsetse once they reached the trap; in addition, the urine brought G. pallidipes to the traps. The efficacy of the residues persisted for at least two months after initial exposure, although urine on soil was ineffective after two days. Efficacies were not affected by the presence of 1-octen-3-ol, acetone or butanone as additional attractants but were lower in the presence of carbon dioxide and lower with electrified visual targets than with traps. A ten times increase in dose caused no clear increase in catches, ten jars of urine being repellent, but catches increased when the urine and sacks were used together.