A trial of a cypermethrin ’pour-on’ insecticide to control Glossina pallidipes,G. fuscipes fuscipes and G.morsitans submorsitans (Diptera: Glossinidae) in south-west Ethiopia

Tsetse populations and trypanosome prevalence in cattle were monitored from 1986 to 1993 in the Ghibe valley, south-west Ethiopia. From January 1991 to December 1993 between 2000 and 4000 cattle were treated at monthly intervals with cypermethrin. An approximate dosage of 1 ml per 10 kg bodyweight was used to control Glossina spp. Treatments were given as ’pour-on’ applications along the backlines of animals, using automatic drench-gun applicators. This resulted in a decline of 93% in the apparent density of G. pallidipes. A reduction of 83% in the apparent density of G. morsitans submorsitans was also observed. This reduction was associated with a reduction in trypanosome prevalence in cattle of over 74% in 1993, despite a high level of resistance to all available trypanocidal drugs. The numbers of Stomoxys spp. and Tabanidae were also significantly reduced (P<0.01).