The chemical and biological properties of methoxyfenozide, a new insecticidal ecdysteroid agonist

Methoxyfenozide [N-tert-butyl-N'-(3-methoxy-o-toluoyl)-3,5-xylohyrazine RH- 2485] is the newest diacylhydrazine insecticide to reach the marketplace. I t binds with very high affinity to the ecdysone receptor complex (EcR:USP) in lepidopteran insects [K-d = 0.5 nM (Plodia)], where it functions as a po tent agonist, or mimic, of the insect molting hormone, 20-hydroxyecdysone ( 20E). Methoxyfenozide exhibits high insecticidal efficacy against a wide ra nge of important caterpillar pests, including many members of the family Py ralidae, Pieridae, Tortricidae and Noctuidae. It is most effective when ing ested by the target caterpillar, but it also has some topical and ovicidal properties. It is modestly root systemic, but not significantly leaf-system ic. Evidence collected to date indicates that methoxyfenozide has an excell ent margin of safety to non-target organisms, including a wide range of non -target and beneficial insects. (C) 2001 Society of Chemical Industry.