Use of dichlorvos in a portable automatic sprayer-mineral station to control face flies (Diptera: Muscidae) and pyrethroid-resistant horn flies (Diptera: Muscidae) on beef cattle

J. Agric. Entomol. 9(4);273-281 (October 1992) ABSTRACT A portable automatic sprayer, actuated when cattle obtain mineral, was tested against face fiies and pyrethroid·resistanL horn nics using 0.5% Al dichlorvos in a waler spray mixture. Horn ny populations were initially 48-fold resistant to pCt-methrin with no '"esistancc to diazinon. Horn Oy control averaged 90.3 to 99.1% reduction. Resistance to permcthrin decreased from 48-fold La 33-fold over 2 yr with no change in diazinon resistance. Face Oy control averaged from 56.4 to 76.8% reduction. The cost for this system of Oy control was approximately 33% the cost of effective insecticide car lags (two/head).