Gamma radiation sensitivity of different life stages of red flour beetle, Tribolium castaneum (Herbst) in stored rice Rani K.S., Mandali Rajasri*, Panduranga G.S. Department of Entomology, Sri Venkateswara Agricultural College, Acharya N.G. Ranga Agricultural University, Tirupati-517 502, Andhra Pradesh, India *Corresponding authors' E-mail : nihashraja@gmail.com
Online published on 4 March, 2024. Abstract Red flour beetle, Tribolium castaneum adults, larva and pupal stages were exposed to different gamma radiation doses at 10, 25, 50, 70, 100, 250, 450 and 1000 Gy using Cobalt-60 source. Among different life stages, Tribolium larvae were found to be more susceptible to gamma irradiation. The larval development was stopped at 100 Gy and complete larval mortality was recorded with 250 Gy exposure. There was no adult emergence from the irradiated grubs at all the test doses of ≥ 10 Gy. The survival rates of emerged adults were decreased with increase in radiation dose and the emerged adults were not survived from irradiated pupae at ≥ 250 Gy. Gamma radiation dose of 1000 Gy led to 100% mortality after one week compared to 3 to 4 months survival of Tribolium adults in the untreated control. Radiation dose of ≥ 50 Gy resulted in complete sterility of adults and there was no F1 adult emergence from the irradiated adults. Probit analysis revealed that ED50 values of 80.89 Gy and 408.67 Gy for larvae and adults of T. castaneum respectively. Similarly, LT50 value of 4.55 days was found at 100 Gy for larvae whereas 11.54 and 9.62 days were found at 250 and 450 Gy respectively for adults of T. castaneum. Weight loss of rice infested with adult beetles was significantly reduced by gamma radiation treatment whereas 4.74% weight loss was recorded with untreated control after two months of storage. Top Keywords Gamma radiation, ED50, LT50, Mortality, Tribolium castaneum, Weight loss. Top |