Fall Armyworm Symposium: Response of Sweetpotato Weevil (Coleoptera: Apionidae) to Selected Insecticides

Abstract

The contact toxicity of five insecticides against adult male and female sweetpotato weevil, Cylas formicarius (F.), was compared using a series of laboratory Petri-dish bioassays. The insecticides tested were chlorpyrifos, parathion, methomyl, carbaryl, and endosulfan. The organophosphates chlorpyrifos and parathion were most toxic, followed by the carbamate methomyl and the chorinated hydrocarbon endosulfan which were moderate in toxicity and the carbamate carbaryl which was least toxic. Slopes differed among insecticides. Parathion exhibited the steepest slope, followed by methomyl, endosulfan, chlorpyrifos and carbaryl, regardless of sex. No differences were found in the susceptibility of males and females to any of the compounds tested. Carbaryl, which had the largest LD