Laboratory and field studies on the integrated pest management of Helicoverpa armigera (Hubner) in cotton, based on pheromone trap catch threshold level

With a view to using parasitoids and predators in integrated pest managemen t of the target pest Helicoverpa armigera in cotton fields, basic studies o n the egg parasitism, toxicity of insecticides to parasitoids and predators and compatibility of nuclear polyhedrosis virus (NPV) of H. armigera with other insecticides were conducted in the laboratory. Results revealed that egg parasitism in the laboratory by Trichogramma chilonis was 75.6%. Among the insecticides tested against T. chilonis and the predator Chiysoperla ca rnea, nimbecidine (neem product) and dipel resulted in zero mortality, with only a low level of mortality by dimethoate, cypermethrin, fenvalerate, al phamethrin and monocrotophos. Combinations of nimbecidine 2% + NPV at 250 l arval equivalents (LE)/ha and dipel 81 + NPV @250 LE/ha were the most effec tive treatments against H. armigera. The integrated pest management compone nts (T. chilonis, C. carnea, NPV, nimbecidine, dipel and synthetic chemical s) were imposed at different intervals on the basis of pheromone trap thres hold level (7 moths/trap per night) on a consolidated block of 40 ha cotton (MCU-1) fields at two locations. Shankarabanda and Korlagundi. The results demonstrated a significant superiority of the IPM strategy in terms of bot h cost versus benefit and environmental safety over that used in the farmer 's fields where only conventional control methods were followed.