Microbial control of insect pest of crops using entomopathogens is pest management strategy. Bacillus thuringiensis (B.t) has a great potential for this purpose. The focus of the present study was to determine the individual and combine effect of different insecticides such as Saraca indica,as a botanical insecticide, Bacillus thuringiensis (B.t), and chemical insecticide against larvae and adults of Tribolium castaneum and results were analyzed by SPSS probit analysis, LC50 was noted for all these insecticides and results were compared with each other. Study was conducted on the enhancement of pathogenicity of Bacillus thuringiensis by 1% sodium citrate and different insecticides such as Bifenthrin+Cypermethrin, Leaves of Saraca indica will also be screened as grain protactant against Tribolium castaneum. Strain of Bacillus thuringiensis SD1 was cultured to use as a toxic agent. Biotoxicity assays were performed to check the mortality rate of Tribolium castaneum which damage the food grains and have become a worldwide problem.