Variation in toxicity of some insecticides against Spodoptera litura(F.) fed on different hosts

Spodoptera litura (F.) reared on three host plants viz., castor, cotton and soybean showed variation in susceptibility to indoxacarb15.8EC and chlorantraniliprole 18.5SC. Against F₃ generation these two insecticides were more toxic when reared on castor (0.036 ppm LC₅₀-indoxacarb and 0.035 ppmchlorantraniliprole) followed by soybean. Higher LC₅₀ of indoxacarb and chlorantraniliprole (0.172, 0.184 ppm, respectively) was observed when reared on cotton indicating that feeding on cotton induced tolerance.