Mechanism of Resistance Acquisition and Potential Associated Fitness Costs in Amyelois transitella (Lepidoptera: Pyralidae) Exposed to Pyrethroid Insecticides

The polyphagous navel orangeworm, Amyelois transitella (Walker) (Lepidoptera: Pyralidae), is the most destructive pest of nut crops, including almonds and pistachios, in California orchards. Management of this insect has typically been a combination of cultural controls and insecticide use, with the latter increasing substantially along with the value of these commodities. Possibly associated with increased insecticide use, resistance has been...