Efficacy of Azadirachtin Oil as Protectant of Wheat Against the Rice Weevil,sitophilus Oryzae (L.) (Curculionidae, Coleoptera)

Abstract

Five concentrations of azadirachtin oil (1%) were tested to evaluate its effect as protectant of wheat grains against the rice weevil, Sitophilus oryzae (L.) infestation. These concentrations wer10, 50, 100, 500 and 1000 ppm, the assay set up on parent adults and the progeny which resulted from them. The results showed that, the percentage of adult mortality in parent adults increased by increasing the concentration of azadirachtin oil through 12 days after treatment compared to untreated control. The used concentrations did not affect on the life span of parent adults. The number of emerged adults (progeny) was greatly affected by the different used concentrations compared to untreated control.. The developmental period of progeny from egg laying to adult emergence on treated wheat significantly longed compared to untreated control. The re was greatly reduction in adult emergence on treated wheat compared to untreated wheat. The percentage of weight loss in untreated wheat (control) was 22% compared with the treatments which were 15.33, 9.33 , 8.5, 6.0 and 4.66% at 10, 50, 100, 500 and 1000 ppm of azadirachtin, respectively. The azadirachtin oil gave a good protection to wheat against the rice weevil.