Status of Insecticide Resistance in Kurnool Population of Spodoptera litura

Status of insecticide resistance in Kurnool(Andhra Pradesh) population of tobacco caterpillar, Spodoptera litura (Fab.) was estimated to choose right insecticide for management, to monitor and develop insecticide resistance management strategies. The LC⁵⁰ (μg per larva) values of lufenuron, emamectin benzoate, novaluron, indoxacarb, profenophos, endosulfan, chlorpyriphos, deltamethrin, quinalphos, spinosad, cypermethrin, dichlorvos, acephate and fenvalrate were 0.0068, 0.0069, 0.030, 0.21, 0.213, 0.645, 0.93, 0.95, 1.02, 1.14, 3.31, 5.1 2, 5.3 and 5.49. LC⁹⁰ (μg per larva) values were also worked out. Taking LC⁵⁰ value of cypermethrin as standard, relative toxicity of other chemicals was worked out. This kind of study would serve as ready-reckoner for the selection of insecticides for the management of field strains and also helpful in development of resistant management strategies for this polyphagous insect pest.