Bioeffieaey of Milk Weed Plant, Calotropis gigantea Against Spodoptera litura

摘要

Laboratory experiments were conducted to determine the insecticidal, antifeedant and ovicidal effect of stem, root, flower and leaves as aqueous and solvent extracts of milk weed plant, Calotropis gigantea R.Br. against tobacco caterpillar Spodopteralitura Fab. eggs and larvae. The results revealed that 5% aqueous leaf extract caused maximum mortality of 53.3% while the solvent extract showed 90% mortality of larvae followed by flower extract (36.6%). Root extract showed least mortality. Regarding antifeedancy, 5% aqueous leaf extract showed least leaf area consumption of 30.3% indicating medium antifceding effect ( +++ ) followed by flower extract. Methanolic leafexract at 5% showed high antifeedant ( ++++ ) activity of 15.5%. Egg hatching was very much affected when they are treated with 5% aqueous leaf extract causing 76.7% and 50% inhibition in 24 and 48 hours old eggs. The solvent leaf extract 5% produced maximum inhibition of 83.3% and was statistically superior to other concentrations tested at all ages of eggs.