Monitoring azinphosmethyl resistance in Archips agyrospila (Lepidoptera:Tortricidae) populations

Azinphosmethyl was applied topically to the dorsal thorax of male fruittree leafroller moths, Archips agyrospila (Walker), caught in pheromone traps from 1986 to 1988 to test the tolerance of this pest within individual orchards. The LC50’s estimated with this technique generally reflected the control problems experienced in the individual orchards and were correlated with the tolerance exhibited by neonate fruit tree leafrollers fed diet containing azinphosmethyl in laboratory bioassays. However, high control mortality, and a lack of understanding of behavior in the adult males in response to pheromones and the natural variation in mortality, decrease the reliability of this technique in assessing the azinphosmethyl resistance of individual fruit tree leafroller orchard populations.