TOXICITY OF SOME INSECTICIDES TO INSECTICIDE-SUSCEPTIBLE STRAINS OF THE ONION, CABBAGE, AND SEEDCORN MAGGOTS (DIPTERA: ANTHOMYIIDAE) AND THE DARKSIDED CUTWORM (LEPIDOPTERA: NOCTUIDAE)

Abstract

AbstractDirect contact toxicity data were obtained with selected insecticides on 24–48 h old adults of insecticide-susceptible onion maggot, Hylemya antiqua (Meigen), cabbage maggot, H. brassicae (Bouché), and seedcorn maggot, H. platura (Meigen); and on third-stage darksided cutworm, Euxoa messoria (Harris). All insecticides were highly toxic to onion maggot flies, with the order of toxicity being: cypermethrin > chlorpyrifos > fenvalerate > permethrin > parathion > isofenphos > terbufos. Chlorfenvinphos was 1.4 × more toxic to cabbage maggot adults than parathion; the pyrethroids were less toxic, with fenvalerate being 1/13 as toxic as parathion. The order of toxicity of insecticides tested on seedcorn maggot flies was: diazinon > cypermethrin > chlorpyrifos > fenvalerate > permethrin. With the darksided cutworm, DDT and leptophos were 1/10 and 3/4 as toxic as chlorpyrifos, while cypermethrin, fenvalerate, permethrin, and decamethrin were ca. 10, 11, 12, and 120 × more toxic, respectively.