STATUS OF INSECTICIDE RESISTANCE IN HELICOVERPA ARMIGERA (HÜBNER) IN SOUTHERN PUNJAB, PAKISTAN

Insecticide resistance in Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) was evaluated against nine insecticides, representing conventional group of neuro-toxic insecticides such as endosulfan, profenofos, carbosulfan, and deltamethrin and new chemistry insecticides such as emamectin benzoate, abamectin, spinosad, lufenuron and methoxyfenozide at IPM Sub Station (PARC), Bahauddin Zakariya University, Multan during 2010-11 . Two bioassay techniques i.e. residual method through leaf dip and topical method through micro-applicator were used for comparison. Low to moderate levels of resistance were recorded against these conventional and new chemistry insecticides at different locations of Southern Punjab, Pakistan e. g. in residual method, endosulfan (05-23 folds), profenofos (02-13 folds), carbosulfan (06-64 folds), deltamethrin (07-108 folds), emamectin benzoate (01-42 folds), abamectisn (03-06 folds), spinosad (01-07 folds), lufenuron (02-08 folds), methoxyfenozide (03-14 folds) and in topical method, endosulfan (05-36 folds),profenofos (02-65 folds), carbosulfan (19-105 folds), deltamethrin (13-35 folds), emamectin benzoate (02-06 folds), abamectin (01-04 folds), spinosad (04-61 folds), lufenuron (02-07 folds), methoxyfenozide (02-07 folds .The results indicated the development of multiple resistances in the field populations of H. armigera. Bioassay techniques showed no significant effects on the toxicity of insecticides. Resistance ratios in topical method were found higher as compared to the residual method, which may be attributed to the delayed cuticular penetration and enhanced metabolism of the insecticides. A significantly negative correlation was observed between conventional and new chemistry insecticides. It is suggested that the rotational use of conventional insecticides along with the new chemistry insecticides may be an effective tool in the insecticide resistance management program of H. armigera.