Department of Entomology, Agricultural College, Andhra Pradesh Agricultural University, Bapatla-522 101, Andhra Pradesh (India).
*Present address: Division of Entomology, Indian Agricultural Research Institute, New Delhi-110 012 (India).
The efficacy of two conventional insecticides, viz, methomyl and triazophos was evaluated either alone or in comibination with biopesticider. NPV and neem oil and diflubenzuron at half of their recommended concentrations on Spodoptera litura (F.) infesting groundnut. The crop was sprayed four times. The combination of methomyl (0.025%) with diflubenzuron (0.0125%) was the most effective, the reduction in larval population over control being 53.23%. This was followed by triazophos (0.025%) + diflubenzuron (0.0125%),the reduction similarly over control was 50.38%. Combinations of these two insecticides with each of NPV 125 LE/ha and neem oil 0.5% were relatively less effective. Methomyl 0.05% and triazophos 0.05% also recorded 45.20 and 43.32%, respectlvely, overall larval population reduction over control. The efficacy of ecofriendly chemicals was not comparable with the other treatment combinations. Different combinations of biopesticides as also diflubenzuron, viz, diflubenzuron (0.0125%) + NPV (125 LE/ha), diflubenzuron (0.0125%) + neem oil (O.S%), and NPV (125 LE/ha) + neem oil (0.5%) were practically ineffective against S. litura.
