Seeds of the tooth pick plant (Ammi visnaga L.) were extracted by organic sol-vents of different polarities, and tested for their toxic effect on Sitophilus oryzae in-festing wheat grains. Toxicity of chloroform extract, was the most potent, at both Lc50 and Lc95 levels (i.e. 3240 and 8730 ppm). Reproductive potential of treated weevil were strongly affected as no progeny were obtained when treated with either Lc50 or Lc95 with A. visnaga. Extracts treatment at Lc95 level organic extract gave protection up to 12 weeks for petroleum ether and chloroform, and 9 weeks when acetone was used for extraction. All tested extracts reduced grain germination at the end of 14 weeks storage period. Also, treated wheat grains with tooth pick extracts reduced the weight loss of grains.