Evaluation of insecticides against Helicoverpa armigera and Spodoptera litura in tomato

Some insecticides were evaluated against the larvae of Helicoverpa armigera and Spodoptera litura on tomato at Bidhan Chandra Krishi Viswavidyalaya, Kalyani during 2012 to 2014 under field conditions. The treatments viz., pyridalyl 10 EC (75 and 150 g a.i./ha), indoxacarb 14.5 SC (75 and 150 g a.i./ha), chlorfenapyr 10 SC (100 and 200 g a.i./ha) and chlorpyriphos 20 EC (350 g a.i./ha) were applied twice with three replications. Pooled results revealed that pyridalyl @ 150 g a.i./ha reduced the larval population of H. armigera (1.05 larvae/5 plants) to an extent of 84.19%. In case of S. litura, larval population was the least with pyridalyl @ 150 g a.i./ha (1.44 larvae/5 plants, and 78.94% reduction). It was at par with indoxacarb @ 150 g a.i./ha (1.53 larvae/5 plants). Pyridalyl was also observed to be the safest as regards coccinellids and spiders, followed by indoxacarb and chlorfenapyr; and chlorpyriphos was highly toxic.