The feeding success of tsetse flies, Glossina pallidipes (Diptera: Glossinidae), on oxen treated with pyrethroid pour-ons at Galana Ranch, Kenya

Publisher Website
Google Scholar
Abstract
An experiment was conducted at Galana Ranch, Kenya, which examined, under natural conditions, whether treatment of oxen with insecticidal pour-ons affects the success with which tsetse flies (Glossina pallidipes Austen) feed on them. An incomplete ring of electric nets was used to sample G. pallidipes approaching and departing from oxen that were either untreated, or treated 6–12 days previously with pour-ons containing deltamethrin or cypermethrin. Eight animals of each treatment were used. There was no evidence suggesting that pour-on application affected the number of G. pallidipes attracted to oxen. A positive relationship was observed between the number of G. pallidipes that approached an ox and the frequency with which it made anti-fly movements. There was also a significant, negative relationship between the rate of anti-fly movements and the proportion of G. pallidipes that fed on the oxen. However, there was no effect of pour-on application on either the rate of anti-fly movement or on the proportion of tsetse that fed. It is concluded that even recent application of deltamethrin or cypermethrin pour-ons to an ox does not affect the ability of G. pallidipes to feed; and that the feeding success of G. pallidipes is density dependent because when more tsetse approach an ox its rate of anti-fly movements increases and the proportion of tsetse that feed decreases.