Insecticide resistance in Helicoverpa armigera from cotton-growing areas in Turkey

Insecticide resistance in Helicoverpa armigera (Hubner) (Lepidoptera: Noctuidae) is one of the most important constraints on cotton production in Turkey. We investigated the susceptibility of H. armigera strains collected from cotton fields in the Adana, Hatay and Antalya provinces to insecticides which are in wide use. LD50 values for tralomethrin, lambdacyhalothrin, enclosulfan, profenofos and methomyl were determined by topical bioassay. At the LD50 levels, resistance ratios for tralomethrin were 24.7-, 19.7- and 15.7-fold in the Adana, Hatay, and Antalya strains, respectively and for lambda-cyhalothrin were 41-, 20and 40-fold, respectively. Resistance ratios ranged from 1.2- to 2. 1 -fold in all field strains for endosulfan, profenofos and methomyl, with no significant resistance. These results suggest the presence of resistance to tralomethrin and lambda-cyhalothrin in H. annigera strains collected from cotton fields, but no resistance to endosulfan, profenofos or methomyl could be observed.