Conventional high-gallonage, high-volume spraying of dairy cattle with 0.03% diazinon, 0.1% coumaphos, 0.1% carbaryl, or 0.1-0.5% Ciodrin® ( alpha -methylbenzyl 3-hydroxycrotonate dimethyl phosphate) controlled cattle biting lice, Bovicola bovis (L.); long-nosed cattle lice, Linognathus vituli (L.); and short-nosed cattle lice, Haematopinus eurysternus (Nitzsch). Ciodrin and carbaryl were not as completely effective as diazinon and coumaphos when herds were sprayed only once. 0.125% rotenone plus 2.5% sulfur required 2 applications for adequate control. Concentrations of Ciodrin as low as 0.03-0.06% applied twice, were completely effective against the chorioptic mange mite, Chorioptes bovis (Hering), but not against lice. An electric mist blower was used to apply low-volume concentrates at 2-8 oz of mist/cow. Ciodrin emulsion, 1-2%, at 8 oz/cow, applied twice, completely controlled all the louse species previously mentioned as well as the chorioptic mange mite. In one of the 8 herds treated, a small number of the little blue louse, Solenopotes capillatus Enderlein, survived 6 weeks after the 2nd application. A similar application of 2% ronnel completely controlled 2 species of sucking lice. Rotenone, 0.5%, applied twice gave good but not complete louse control, and was not effective against the chorioptic mange mite. Ciodrin was tested also as a 2% solution in a livestock spray oil at 71-107 ml/cow and completely controlled cattle biting and sucking lice and chorioptic mange mites with 2 applications. Also effective was 83-150 ml/cow of 1 % Ciodrin plus 0.25% dichlorvos solution. Dichlorvos, 1%, alone was effective against all louse species but not the chorioptic mange mite. Preliminary experiments indicated that 2% trichlorfon, 2% coumaphos, and 1% fenthion were effective when applied as a low-volume mist. Emulsions containing 8.3% Ruelene® (4-tert-butyl-2-chlorophenyl methyl methylphosphoramidate) or 5% fenthion, poured on the backs of cattle, reduced populations of the cattle biting louse and the long-nosed cattle louse. Two applications of Ruelene did not completely control the cattle biting louse.