Sheep Ked Control With 1% Diazinon Dust

Three farm flocks of sheep were power dusted with 1% diazinon sheep dust in spring of 1975 after the ewes had been shorn. All sheep in each flock were driven through a curtain of dust expelled by a Howry-Berg sheep duster. Dusting rates were determined by weighing the dust before and after treatment and timing the duration of the dusting period. Parasite density was determined by a total count of adult sheep keds on 5 lambs and 5 ewes of each flock immediately before treatment and again 6 wk later. One untreated check flock was examined for parasite density in the same manner.