Cyonara Pour-On Topical Insecticide a topical insecticide that provides long-lasting residual control of lice and horn flies on beef cattle, cows and calves (not recommended for use on veal calves). May be applied to cattle at any time during the year. One quart treats 94 head of 600-lb. cattle; a gallon treats 378 head of 600-lb. cattle. Active ingredient is 1% lambda-cyhalothrin.