Efficacies and antifeedant analysis of selected insecticides against Sitophilus oryzae (coleoptera: curculionidae) / Ismeazilla Mohd Bukhari

The rice weevil, Sitophilus oryzae (Coleoptera; Curculionidae) is broadly spread all around the world. This stored pests can cause losses to grain in storage after harvesting process due to inaccurate application of insecticides used. The laboratory bioassay were conducted at the toxicology laboratory of University Putra Malaysia in order to evaluate the toxicity and the antifeedant activity of five insecticides which is Cypermethrin, Malathion, Prevathon, Rotenone and also Spinosad against the adult of S.oryzae by using the filter paper impregnation method and also food impregnation method. Thus, feeding deterrent index also were evaluated. In this experiment, S. oryzae from UPM’s stock culture were reared for appropriate 45 days in order to have a new generation of adult emerge. For each insecticides, six different concentration were undergo serial dilution with eight replication were done in order to get the solution that were tested in this experiment. Hence, 10 adult of S.oryzae were used for each method and were evaluated for 1, 3, 5 and 7 days. Among all the insecticides, were found to be effectives in toxicity via filter paper impregnation method based on the LC50 values was Rotenone with 0.003% while the other was 0.04%, 0.017%, 0.106% and 1.109% were indicated Spinosad, Malathion, Cypermethrin and Prevathon. The less effective was Prevathon.