was performed by exposing neonate larvae to semi synthetic diet (Nagarkatti and Prakash, 1974) dispersed into 1.8 ml cryovial (Tarson ; 1 cm dia.) smeared with different concentrations
(1 lg, 2 lg, 3 lg, 4 lg, 5 lg) of the purified Cry2Al1 protein. Fifteen larvae were used in each treatment and every treatment was repli- cated 3 times. Larval mortality was recorded periodically for seven days of exposure. For Cry2A protein, mortality data of at least five concentrations were used for probit regression analysis (SPSS,
1995) to find out LC50 (LC - Lethal concentration) values.