ABSTRACT
Microorganism based biopesticides have attracted greater attention during last decades for biological control of plant pests. The use of microorganisms as a source of biological compounds for insect pest control started with the discovery of the highly insecticidal bacteria Bacillus thuringiensis. By far, the most successful of microbial insecticide in agricultural and forest insect pest control is Bacillus thuringiensis subsp. kurstaki (Btk). Until the mid 1970s, Bt (mainly Btk) was thought only to produce proteins that were insecticidal to lepidopterous insects. In 1976, Goldberg and Margalit isolated a new subspecies of Bt named israelensis (Bti) which was found to be a pathogen of mosquito larvae. This discovery of a new subspecies of Bt led to much research into its possible use of mosquito control. After the successful development of Bti as a larvicide for some mosquitoes and blackflies, another Bacillus species, sphaericus was developed to complement Bti in the control of various mosquito species in diverse habitats. Detailed descriptions of individual characteristics, insecticidal properties and safety profiles of all the three above mentioned Bacillus species are provided in this chapter.
