Development of resistance in Helicoverpa Armigera (hubner) to cypermethrin in Jammu and effect on its biology

Application of sub-lethal concentrations of cypermethrin to the 3^rd instar larvae of Helicoverpa armigera up to five generations registered survival at the highest concentration, i.e. 0.25, 0.45, 0.65, 1.10 and 2.25, respectively, in each successive generation after exposure. The resistance ratio increased up to 4.44–folds as compared to first generation. Out of seven biological parameters studied for cypermethrinselected, parental and susceptible strains, three parameters viz. oviposition period, fecundity and female adult longevity were significantly affected.