Laboratory experiments were conducted under controlled conditions to test the insecticidal activity of
aqueous and organic extract of different solvents 􀀬ethanol, acetone and hexane􀀭 from 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 Rust-Red Flour Beetle, Tribolium castaneum H. The results showed that the aqueous extract of N. glauca
gave the highest toxicity among the other tested plants with LD5􀀜 equal to 􀀜.􀀜􀀜􀀜86 x 􀀝􀀜5 ppm using ethanol solvent.
However, the organic extracts of M. azedarach L. showed the best result with LD5􀀜 equal to 􀀜.􀀜􀀜􀀜2 x 􀀝􀀜5 ppm. On the
other hand, both the aqueous and organic extracts of N. glauca gave the highest toxicity with LD5􀀜's of 􀀜.􀀜􀀜􀀝6 x 􀀝􀀜5
ppm and 􀀜.􀀜􀀜􀀜66 x 􀀝􀀜5 ppm, respectively, with acetone solvent. But using hexane solvent, aqueous extract of C. limon
L. was obviously the most toxic extract compared to the aqueous extracts of the tested plants with LD5􀀜 􀀬􀀜.􀀜􀀜86 x 􀀝􀀜5
ppm􀀭 and in the organic phase N. glauca gave the best result with LD5􀀜 equal to 􀀜.􀀜􀀜􀀜7 x 􀀝􀀜5 ppm .