Food production requires adequate assurance against the havoc caused by insects. This has lead to the short sighted, unilateral and almost exclusive employment of synthetic chemicals for insect pest control. Application of these broad – spectrum pesticides results in environmental pollution by chemical residues or their immediate harmful action on non–target species. Therefore, the development of new and alternative environmentally friendly control agents with greater emphasis on, and a wider role for biological control is urgently needed. Microbiological control includes all aspects of the utilization of micro-organisms or their by-products in the control of insect pests.The major species of bacteria possessing mechanism to infect and kill uncompromised healthy insects are the spore forming Bacilli. Bacillus thuringiensis is a typical soil bacillus characterized primarily by its ability to form proteinaceous crystals. It is these crystals which are toxic to a number of insect larve. The use of Bacillus thuringiensis as an insecticide can only be beneficial to man from the industrial and ecological point of view provided this system is not misused or abused.