Life table study of tobacco caterpillar spodoptera litura (F.) (Noctuidae: Lepidoptera) on different Bt cotton hybrids during 120-150 DAS (Days after Sowing)

Survival and fertility characteristics of the third instar larvae of Spodoptera litura (Fabricius), on Bt-I and Bt-II cotton hybrids during 120-150 DAS were assessed in the laboratory. Life tables and population parameters of the S.litura were constructed in an environment with unlimited food supply and that was free of natural enemies. The results revealed that the modest rate of mortality occurred in the immature stage, especially in the third instar. The population parameters calculated are recorded as low in Bt-II hybrids compared to Bt-I hybrids.