ABSTRACT
About 700 species of fungi belonging to ~90 genera have been identifi ed with an entomopathogenic habit (Roberts and Humber 1981). Fungi are highly diverse spanning all the major taxonomic groups of fungi except the higher Basidiomycetes. Some of these species cause disease epidemics in insect populations leading to their mass knockdown, a phenomenon technically described as ‘epizootics’. Epizootics on insect pest populations in standing crops are a respite to the farmers. Impressive natural epizootics wiping out insect pests in crop fi elds have been extensively reported. Emulating the natural phenomenon, artifi cial induction of epizootics through formulations made from fungal propagules has been attempted in numerous instances with reports of varied success. These mycopesticides utilized in biological control of insect pests are few compared to the number of fungi with entomogenous habit. Only fi ve species of Ascomycetes with a predominantly mitosporic life cycle have been registered as biopesticides (Butt et al. 2001). Fungi include Beauveria bassiana (Bals.) Vuillemin, Metarhizium anisopliae (Metsch.) Sorokin, Nomuraea rileyi (Farlow) Samson, Verticillium lecanii (Zimmermann) Viegas and Paecilomyces fumosoroseus (Wize) A.H.S. Br. and G. Sm. Thus, there is a large yet to be tapped potential of entomogenous fungi in insect pest management. Realizing their potential is a priority to censor the unwarranted loss world-wide of more than 30% of agricultural produce to insect pests. In addition to fungi, bacteria, viruses, nematodes and protozoa are among the list of insect pathogens. Bioinsecticides based on the bacterium Bacillus thuringiensis Berliner 1915 (Bt) are a paradigm of success of microbial biopesticides and also in transgenic approach for development of insect resistant plants. Entomopathogenic fungi infect insects through their cuticle and cause death of the insect by systemic infection and parasitization unlike the bacterial entomopathogens like Bt which kill through a toxin. Therefore, built up of resistance in insect populations to fungal pathogens is diffi cult if not impossible unlike the case of Bt where resistance to the transgenic plants with the cry toxin gene of Bt has been recorded.
