Synthetic insecticides has long been involved in causing fetal diseases to human beings as well as cattle. Importance of biological control of insect pests is aan environment friendly approach. With advances in biotechnology, recombinant bacteria and other organisms are being developed for better control of insect pests. Bacillus thuringiensis (BT) holds a central place among biocontrol agents. BT produces parasporal crystal proteins (Cry toxin) during sporulation phase of its growth. These toxins have defined spectra of toxicity to the target insects only, without doing any harm to friend insects. More than 260 Cry toxins have been reported so far. Of which Cry2 is toxic to lepidopteran as well as dipteran insects. When enters the insect midgut, the toxin gets activated by proteases present in the insect midgut, make holes in the gut, as a result insect loses homeostasis and eventually die without feeding.