Field Survey of Insecticide Resistance in Haematobia irritans exigua de Meijere (Diptera: Muscidae)

Abstract

A survey of farms in northern New South Wales and southeastern, central, western and northern Queensland was conducted to determine levels of insecticide resistance in populations of buffalo fly Haematobia irritons exigua. A field bioassay using discriminating concentrations of 10 insecticides commonly used for buffalo fly control was used. Resistance to all synthetic pyrethroids tested (cypermethrin, deltamethrin, cyhalothrin, flumethrin and cyfluthrin) was common and widespread in coastal zones, but was lower in inland zones. In contrast, there was no resistance to the organophosphate diazinon and only low levels of resistance to ethion and chlorfenvinfos. Synergism between piperonyl butoxide and cypermethrin was demonstrated.