Insecticidal Activity of Root Bark of Calotropis gigantea L. Against Tribolium castaneum (Herbst)

The residual film toxicity, fumigant toxicity and repellent effect of methanol extract of root bark of Calotropis gigantea (Linn) and its chloroform and petroleum ether (40-60°C) soluble fractions were evaluated against several inster of larvae and adult of Tribolium castaneum. In residual film toxicity, methanol extract and its chloroform and petroleum ether fractions showed insecticidal activity against T. castaneum and data were analyzed by probit analysis. Methanol extract showed lowest LD values against several inster of larvae and 50 adult (121.59, 142.73, 146.84, 202.98, 290.65, 358.42 and 300.03 μg/cm , respectively) which indicates highest 2 toxicity or insecticidal activity. Whereas LD values of petroleum ether extract were 407.69, 485.46, 437.38, 50 235.51, 256.25, 369.66 and 411.84 μg/cm in case of 1 , 2 , 3 , 4 , 5 , 6 inster larvae and adult, respectively and 2 st nd rd th th th for chloroform extract that were 291.83, 299.29, 382.98, 745.18, 637.71, 1259.42 and 739.87μg/cm , respectively. 2 The order of toxicity on T. castaneum was methanol extract> petroleum ether fraction> chloroform fraction. No fumigant toxicity of test samples was found. In the treated filter paper repellency test, methanol extracts and also its chloroform and petroleum ether soluble fractions were repellent to Tribolium castaneum in mild to moderate range.