Assessment of LC50 value of deltamethrin 2.8 EC, cypermethrin 25 EC, endosulfan 35 EC against Spilosoma obliqua Walker

The toxicity of some insecticides viz., deltamethrin, cypermethrin and endosulfan were determined against same age larvae (7 day old) of Spilosoma obliqua by leaf dip method at different concentrations 0.2, 0.02, and 0.002 percent for deltamethrin 2.8 EC, 0.4 0.04 and 0.004 for cypermethrin 25 EC and 08, .04 and .01 for endosulfan 35 EC. Deltamethrin proved to be the most toxic and quick acting insecticide amongst all the insecticide followed by cypermethrin and endosulfan during observation at12, 24, 48 and 72h after feeding . On the basis of LC50 values at different time intervals the order of toxicity was, deltamethrin > cypermethrin > endosulfan. These findings can be helpful for the selection of suitable insecticides for effective pest management under field condition.