Joint action of microbial and chemical insecticides on spodoptera Litura (fab.) (lepidoptera: noctuidae)

Abstract

The evaluation of treatments in the control of Spodoptera litura (Fab.) on groundnut under glasshouse conditions revealed that combinations of microbial pesticides (nuclear polyhedrosis virus @ 1 x 107 PIBs ml"1, Bacillus thuringiensis subsp. kurstaki @ 1 x 10 spores ml"1 and Beauveria bassiana @ 1 x 107 spores ml"1) along with chemical insecticides (fenvelerate @ 0.005% and monocrotophos @ 0.025% i.e., half of the recommended dose) and microbial pesticides themselves were superior to either microbial pesticides or recommended rates of individual chemical insecticides alone. B. thuringiensis 1 x 107 spores ml + fenvelerate 0.005 per cent was proved as the best in respect of highest larval population reduction and lowest leaf damage (20.15 per cent). The highest pod yield (15.03 g pant"1) was recorded with the same treatment (B. thuringiensis 1 x 107 spores ml"1 + fenvelerate 0.005 percent).