Evidences for newer insecticides and growth regulators resistance in field populations of Helicoverpaarmigera (Lepidoptera: Noctuidae) in Karnataka,India

Abstract

AbstractThe prominence of Helicoverpaarmigera(Lepidoptera: Noctuidae)averse insecticide resistance was traversed in the course of 2017 in Karnataka,India. The results divulged typical resistance level prostrating in selected newer insecticides, even though exiguous higher resistance airing in insect growth regulator Novaluranwith LC 50of and 13.02 to 18.07 ppm and 1.17 to 1.95 folds resistance) compared to newer group insecticides Spinasad, Indoxacarb, Flubendiamide and Rynaxypyr(3.57 to 10.19 ppm, 1.01 to 1.27 fold). Raichur and Kalaburgi strains comprehend higher resistance to Novaluran and newer insecticides with exception of Flubendiamide (Raichur and Vijayapura strains), respectively and Spinosad (Kalaburgi and Raichur strains), respectively. The morphometric parameters of larval length, pupal length, and weight were most in RCH stain (2.75±0.48 cm, 1.76±0.18 cm, and 0.511±0.04 g, 0.309±0.05 g) respectively, which was pursued by Kalaburgi strain. The morphometric correlation revealed that larval length was a significant positive relation with insecticide resistance which might be an influence of resistance but not merely responsible. Among newer insecticides, a significant positive correlation between Rynaxypyr and Indoxacarb was evident, similarly, Nuvaluran with Indoxacarb and Rynaxypyr as well. Usage pattern revealed that 81.67 % of farmers found to use insecticides more than the recommended dose and 70.83% have habit consecutive applications of products from the same chemical group which bear witness to developing resistance.