Insecticidal potential of the bioagent radiant sc 12% against stored rice weevil, Sitophilus oryzae L. (Curculionidae: coleoptera)

Document Type : Original Article


1 Plant protection Department, Faculty of Agriculture, Ain Shams University, Cairo, Egypt

2 Biological science Department, Faculty of Science, Taif University, Taif, El-Hawyeia 888, Saudi Arabia.

3 Zoology Department, Faculty of Science, Zagazig University, Zagazig, Egypt


The bioagent, Radiant SC12% (Spinetoram) is a commercial reduced-risk pesticide that is naturally derived. Efficacy of five concentrations (1.8, 0.93, 0.46, 0.23 and 0.11ppm) of spinosad against adults of the rice weevil, Sitophilus oryzae was studied under laboratory conditions. Data obtained demonstrated that the highest concentration of the bio-agent Radiant SC 12% (1.87 and 0.93 ppm) achieved the highest mortality percent of adults (55 and 31 %, respectively) after 4 days of treatment and 100 mortality percent for both two concentrations after 6 and 8 days of treatment. Antioxidant defense components protect insects by scavenging reactive oxygen species, leading to oxidative stress. The present study also investigated the effects of Radiant SC 12%, on the oxidative stress indicator, and antioxidant enzymes [superoxide dismutase (SOD) and catalase (CAT)] activities in Sitophilus oryzae tissues. The use of the bio- agent lead to statistically significant increases in SOD and CAT activities after 48h of application as compared to untreated Sitophilus oryzae. These results indicated that Radiant causes a significant increase in oxidative stress, that increasing oxidative stress induces antioxidant defense mechanisms, which lead to mortality action.