Selectivity of methoxyfenozide to non-target arthropods

Methoxyfenozide is a unique insect growth regulator that displays very little to no adverse effects on honey bees and other non-target arthropods.  Unlike chitin synthesis inhibitors or juvenile hormone analogues, methoxyfenozide is an ecdysone agonist from the bisacylhydrazine family of insecticides highly specific for Lepidopteran insects.  Mode of action studies show that it mimics 20-hydroxyecdysone causing premature molting in larval stages of target Lepidoptera.  Cellular and molecular studies have shown extremely high binding affinity to Lepidoptera ecdysone receptors, which accounts for its very specific spectrum of activity.  This specificity to Lepidoptera accounts for the very low to no toxicity in non-target arthropods including predators, parasites, and honey bees. A review of toxicity studies with honey bees will be presented.