Horn fly susceptibility to diazinon, fenthion, and permethrin at selectedelevations in Wyoming

摘要

Horn fly, Haematobia irritans (L.) (Diptera: Muscidae), populations from southeastern Wyoming were assayed for resistance against permethrin, diazinon, and fenthion. All of the populations examined were significantly more resistant to permethrin than a susceptible strain. Eight of 25 populations examined were significantly more resistant ito diazinon than a susceptible strain. Five of 15 populations examined were significantly more resistant to fenthion than a susceptible strain. No relationship was detected between elevation and resistance levels.