Comparative efficacy of insecticides against the American bollworm, Helicoverpa armigera “Hu˙˙b.” of cotton

Larvin 80DF, Lannate 40SP, Lorsban 40EC, Fastac 5EC, Decis 10EC and Fury-F18.1EC were tested with recommended doses against 3rd instar larvae of American bollworm, Helicoverpa armigera “ Hu˙˙b.” under controlled laboratory conditions. Lorsban 40EC showed maximum efficacy 92.0 % in terms of mortality after 24 hours. Maximum mortality was shown by Lorsban 40EC (100%) followed by Larvin 80DF (72.0%), Lannate 40SP (52.0%), Decis 10EC & Fastac 5EC (16.0%) and Fury-F 18.1EC (8.0%) after 48 hours of application. Similarly, the maximum effectiveness was shown by Lorsban 40EC (100%) after 72 hours followed by Larvin 80DF (80.0%), Lannate 40SP & Fury-F 18.1EC (60.0%), Decis 10EC (52.0%) and Fastac 5EC (44.0%). It is concluded from the results obtained that Lorsban 40EC is the most effective insecticide compared to other carbamate and pyrethroid groups of insecticides against 3rd instar larvae of American bollworm, H. armigera.