Treated Filter Paper Bioassay for Detection of Insecticide Resistance in Haematobia irritans exigua de Meijere (Diptera: Muscidae)

Abstract

This paper reports on the standardisation of an assay, whereby buffalo flies Haematobia irritans exigua de Meijere from a laboratory population which had not been exposed to insecticides for 8 years were confined in Petri dishes containing filter paper treated with known concentrations of insecticide. Mortality was assessed after 2 and 4 h and mean LC50 and LC99 values for each of 11 insecticides were calculated. The bioassay technique had acceptable repeatability and was simple to perform. Field populations of northern Queensland buffalo fly were assayed using the technique and were found to have high levels of pyrethroid resistance and little or no organophosphate resistance.