FIELD EVALUATION FOR EFFICACY OF CONVENTIONAL INSECTICIDES AND INSECT GROWTH REGULATORS AGAINST SPOTTED BOLLWORMS, EARIAS SPP. OF COTTON

Spotted bollworms (SBW) are important pests of cotton. Its larvae bore into the growing shoots, flower buds, flowers and bolls of cotton resulting in considerable losses in quality and quantity. Field studies were conducted to evaluate the insecticidal toxicity of four conventional insecticides (deltamethrin, cypermethrin, bifenthrin and chlorfenapyr) and four insect growth regulators (IGRs) (chlorfluazuron, pyriproxyfen, methoxyfenozide and buprofezin) against SBW. Cotton variety, BH-167 was sown in Randomized Complete Block Design (RCBD) with three replications at the farm area of The Islamia University of Bahawalpur, Pakistan. The percentage bolls infestation and population reduction was calculated at 3 and 7 days after treatment (DAT). Deltamethrin showed comparatively better results with minimum percentage bolls infestation (4.35% and 1.82%) and maximum percentage reduction in SBW larvae population (64.4% and 100.0%) at 3 DAT and 7 DAT, respectively. Deltamethrin also gave prominently significant results for increase in seed cotton yield (2043.2 kg/ha). It was also observed that insecticides were found most effective on both 3 DAT and 7 DAT as compared to the IGRs. However, the effect of IGRs against SBW was enhanced at 7 DAT as compared to their effect at 3 DAT. Taken together, deltamethrin was found most effective against SBW with a significant increase in the seed cotton yield.