ABSTRACT
The pwpose of formulation of a microbial system is to produce a product that optimizes the effective and economical use of a toxin, within a particular environment. Bacillus thuringiensis subsp. israelensis (Bti) formulation, a mosquito biolarvicide, for example, is used in an aquatic environment. On the other hand, Bacillus thuringiensis subsp. kurstaki (Btk) formulation, a product for control of agricultural insect pests, is applied through foliar application. In order to be effective, both of these products should be easily accessible to their respective target larvae and should be reasonably stable under field conditions. Thus, even though the nature of insecticidal crystal proteins (ICPs) and spores are similar in both cases, the fmal product has to be applied to different environments, with specific requisites for accessibility and stability.
