A TRIAL OF A CYPERMETHRIN POUR-ON INSECTICIDE TO CONTROL GLOSSINA-PALLIDIPES, G-FUSCIPES FUSCIPES AND GLOSSINA-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 Janu ary 1991 to December 1993 between 2000 and 4000 cattle were treated at monthly intervals with a synthetic pyrethroid insecticide, cypermethr in (RS-alpha-cyano-3-phenoxybenzyl [IRS]-cis, ans-3-[2,2-dichlorovinyl ]-2,2-dimethylcyclopropane carboxylate). An approximate dosage of I mi per 10 kg bodyweight was used to control tsetse flies (Glossina spp.) . Treatments were given as pour-on' applications along the backlines o f animals, using automatic drench-gun applicators. This resulted in a decline of 93% in the apparent density of G. pallidipes Austen. A redu ction of 83% in the apparent density of G. morsitans submorsitans News tead was also observed. This reduction was associated with a reduction in trypanosome prevalence in cattle of over 74% in 1993, despite a hi gh level of resistance to all available trypanocidal drugs. The number s of Stomoxys spp. (Diptera: Muscidae) and Tabanidae were also signifi cantly reduced (P < 0.01).