Insecticide Resistance Management of Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) and its effect on pests and yield of cotton in North India

An insecticide resistance management (IRM) strategy was devised and evaluated for the management of cotton bollworm, Helicoverpa armigera (Lep., Noctuidae) in cotton in on-farm research in Punjab state, India, in 2003–2004. The adoption of the IRM programme, based mainly on economic thresholds and on the use of selectively acting insecticides, resulted in significantly lower incidence of cotton bollworms and of homopteran pests in conjunction with a reduced use of insecticides. Beneficials (predatory bugs and spiders) tended to be more frequent. The number of insecticide sprays per season in IRM plots (9.5) was less than in non-IRM plots (14.5). Laboratory tests showed that the IRM strategy resulted in a significant decline (1 to 2.9-fold) in resistance of H. armigera larvae to cypermethrin, fenvalerate, endosulfan, methomyl, quinalphos and chlorpyriphos. A significant cotton yield increase of 28.7% (0.62 t/ha) was observed. The economic analysis showed a net return of $ 291.3/ha in IRM plots compared to non-IRM plots but the costs of advice and scouting are not included here. The results demonstrated the superiority of IRM strategy over the present farmers practice (unnecessary use of insecticides, practically no monitoring), and thus help in reviving the confidence of traditional cotton growers in a more sustainable cotton cultivation.