Effect of gamma radiation on growth and development of the tobacco caterpillar [Spodoptera litura (Fab.)]

The effect of different doses of gamma radiation on the growth and development of Spodoptera litura (Fab.) was studied in the department of Agricultural Zoology and Entomology, Rajasthan College of Agriculture, Udaipur during 2001–2002. The second and third instar larvae irradiated with different doses of gamma radiation (8, 10, 12 and 14 Krad) evinced a gradual decrease in the number of larvae reaching the sixth instar with the lowest recorded at 12 Krad, (27.36 and 27.33%). A dose dependent increase in the larval period and the larval, pupal and adult deformity and mortality was observed. The highest respective mortality was 72.67 and 74.00 er cent at 12 Krad. There was a gradual decline in the pupal formation, pupal period, adult emergence and adult longevity.