摘要 : Direct and residual toxicities of seed extracts and leaf powders of the neem tree Azadirachta indica, marigold Tagetes erecta and durba Cynodon dactylon along with two commercial insecticides malathion and carbaryl, respectively t... 展开 Direct and residual toxicities of seed extracts and leaf powders of the neem tree Azadirachta indica, marigold Tagetes erecta and durba Cynodon dactylon along with two commercial insecticides malathion and carbaryl, respectively towards the red flour beetle Tribolium castaneum, a major stored-product pest, were evaluated. All seed extracts and leaf powders showed a certain degree of toxicity towards the insects Among the tested plant derivatives, neem seed extract 100 ug/insect showed higher direct toxicity 53,1.3 % mortality towards red flour beetles than marigold 46.88 % and durba .37 % seed extracts. On the other hand, marigold leaf powder 5 % showed a higher residual toxicity 57.09 % inhibition ratio than neem 50,06 % anddurba 4.3,28 % leaf powder. Compared with the commercial insecticides malathion and carbaryl, neem seed extract and marigold leaf powder possess a potential as natural alternative insecticides towards the red flour beetle in stored products. 收起