Department of Entomology, Punjab Agricultural University, Ludhiana-141 004, Punjab, India.
*Correspondence address: Senior Cotton Specialist, Pest Management Department, NRI-London, U.K.
Online published on 31 October, 2011.
Resistance in the larvae of Helicoverpa armigera Hiibner collected from cotton and non-cotton growing areas of Punjab to cypermethrin, fenvalerate, endosulfan, quinalphos and methomyl was determined. Significant level of multiple resistance was detected in pest population from cotton growing areas, using topically-applied discriminating doses of insecticides. Resistance manifested to synthetic pyrethroids was of higher order as compared to other insecticides tested. By using leaf-disc bioassay method, the level of resistance to cypermethrin and chlorpyriphos ranged from 3 to 5 and 1.3 to 3 folds, respectively, compared to the Hoshiarpur populations. The studies also showed that fifth instar larvae were 17 times more tolerant to chlorpyriphos than the first instar larvae of H. armigera.
Helicoverpa armigera, resistance, cypermethrin, fenvalerate, endosulfan, quinalphos, methomyl, chlorpyriphos
