I. AKHILA*, RAJASRI MANDALI1 AND K. DEVAKI 

Department of Entomology, S.V. Agricultural College, ANGRAU, Tirupati. 

ABSTRACT

A study was conducted on the effect of gamma irradiation on survival and progeny development of groundnut bruchid, Caryedon spp. (Coleoptera : Bruchidae) 2020-21. Freshly emerged adults were exposed to different doses of gamma irradiation viz., 10, 30, 50, 100, 250 and 500 Gy along with an untreated control. Five days after gamma irradiation, all the adult bruchids were killed at 250 Gy and higher doses compared to 100 per cent survival in the untreated control. All the irradiated adults laid the eggs in the range of 172.33 to 89.67 eggs between 10 Gy to 100 Gy doses compared to 237 eggs/100 pods in untreated control. The sterile eggs were laid by the irradiated adults and there was no embryonic development from the dose of 30 Gy onwards. Bruchid emergence was not recorded from 20 Gy dose onwards. Hence, the groundnut bruchids require 250 Gy for acute mortality within five days of treatment but 30 Gy dose is sufficient to induce sterility in adults and in suppressing the F1 population build up in groundnut. Gamma irradiation was proved to be an effective alternative measure for the management of Caryedon spp. in stored groundnut. 

KEYWORDS: Groundnut, Gamma irradiation and Gy.