Resistance Monitoring of Helicoverpa armigera to Insecticides Across Locations of Karnataka

This study evaluates the toxicity of eight insecticides against Helicoverpa armigera (Hubn.). These include conventional and newer molecules which are being used on a large scale in six districts (Raichur, Kalaburagi, Bidar, Dharwad, Ballari, Bengaluru and Gangavathi) of north eastern Karnataka. The results revealed that the least LC50 value was observed in chlorantraniliprole 18.5%SC (0.17- 0.39 ppm- 2014-15; 0.19-0.43 ppm- 2015-16; and 0.70-0.94 ppm- 2016-17. Maximum LC50 value was observed with chlorpyriphos 20%EC (35.16-41.08; 37.35-43.27; and 36.02- 41.94 ppm). The order of toxicity was chlorantraniliprole > emamectin benzoate > flubendiamide > spinosad > thiodicarb > methomyl > profenophos > chlorpyriphos. These results reveal that rotation of conventional insecticides along with the new insecticides might be more effective.