Dose-Response relationship of some insecticides with Helicoverpa armigera hübner (Lepidoptera; Noctuidae) under laboratory conditions

Dose response of some insecticides against H. armigera were checked under laboratory conditions, following the guidelines recommended by the Insecticide Resistance Action Committee (IRAC). Five different concentrations were used i.e. Field Recommended Concentration (FRC), quarter, half, double and quadruple of the FRC of all the insecticides viz, emamectin benzoate (Emamectin benzoate® 1.9 EC), lufenuron (Match® 50EC), flubendiamide (Belt 480® SC), spinosad (Tracer® 240 SC), indoxacarb (Steward® 150 EC), deltaphos (Deltaphos® 36 EC), thiodicarb (Larvin® 80 DF) and a botanical product (Neem oil) against 2nd instar H. armigera larvae. Results showed that emamectin benzoate is most potent, followed by flubendiamide, lufenuron, spinosad, indoxacarb and neem oil. Spinosad, closely followed by indoxacarb and flubendiamide were the quickest in exerting their lethal effect on the larvae. The pest expressed mild level of tolerance against deltaphos and thiodicarb with LC50 and LT50 values much higher than their respective FRCs and the rest of insecticides.