Sheep Ked Control with Pour-On Applications of Organophosphorus Insecticides12

Pour-on applications of diazinon at 42.2 mg/kg to lambs and shorn ewes eradicated infestations of Melophagus ovinus (L.). Substantial reductions of ked populations were provided by coumaphos at 14.4 mg/kg, crufomate at 40.0 and 80.0 mg/kg, diazinon at 31.6, 21.0, 10.5, and 5.3 mg/kg, and ronnel at 31.6 mg/kg. All insecticides that were used had an established residue tolerance in sheep, and all formulations were available commercially in the United States.