The life fecundity tables of H. armigera were constructed on squares/bolls of Bt and non Bt cotton. In non Bt cotton, 75 adults and in Bt cotton, 8 adults emerged successfully from a cohort of 100 eggs. In non Bt cotton, the net reproductive rate (R0) was 416.84, the finite rate of increase (X) was 1.1371 females per female per day, the mean generation time (T) was 46.58 days and intrinsic rate of natural increase (rm) was 0.1293. In Bt cotton, the net reproductive rate (Ro) was 47.05, which was very less as compared to non Bt Cotton. Life table studies showed that only 12 out of 100 larvae could manage to survive up to last instar and the adult emergence was restricted to nearly 8 per cent in Bt Cotton.
