Toxicity of insecticides toEpiphyas postvittana(Walker) andPlanotortrix excessana(Walker) (Lepidoptera: Tortricidae)

The responses of Epiphyas postvittana and Planotortrix excessana (Lepidoptera: Tortricidae) larvae to insecticides were compared using three laboratory methods: topical application, direct application, and exposure to residues. The order of toxicity was fenvalerate > chlorpyrifos > azinphos-methyl > phosmet for topically applied insecticides on E. postvittana, and fenvalerate > azinphos-methyl for P. excessana. For technical grade insecticides applied to first instar E. postvittana larvae in a Potter tower, the order of toxicity was deltamethrin > cypermethrin > fenvalerate > permethrin > azinphos-methyl > triazophos > chlorpyrifos > azinphos-ethyl > phosmet > carbaryl > etrimphos > DDD. Against first-instar P. excessana larvae, with the same method, the order of toxicity was cypermethrin > fenvalerate > azinphos-methyl > chlorpyrifos > phosmet > carbaryl. After exposure of first-instar E. postvittana and P. excessana to residues, the order of toxicity was deltamethrin > chlorpyrifos > cypermethr...