Insecticidal Properties of some Plant Extracts against Granary Weevil, Sitophilus granarius L.

Abstract

Laboratory experiment was conducted under controlled conditions to test the insecticidal activity of aqueous and organic extract of different solvents (ethanol, acetone and hexane) of three plants collected from north-Sinai (Tree tobacco, Nicotiana glauca G.; Chinaberry, Melia azedarach L. and Lemon, Citrus limon L.) against the adult stage of Granary Weevil, Sitophilus granarius L. The results showed that the aqueous extract of C. limon gave the highest toxicity among the other tested plants with LD50 equal to 0.0013 x 10 5 ppm using ethanol solvent. However, the organic extracts of M. azedarach L. showed the best result with LD50 equal to 0.00056 x 10 5 ppm. On the other hand, both the aqueous and organic extracts of N. glauca gave the highest toxicity with LD50's of 0.0056 x 10 5 ppm and 0.00086 x 10 5 ppm, respectively, with acetone solvent. But by using hexane solvent, aqueous extract of N. glauca was obviously the most superior in toxicity compared to the aqueous extracts of the tested plants with LD50 (0.0017 x 10 5 ppm) and in the organic phase M. azedarach had the best result with LD50 equal to 0.00017 x 10 5 ppm .