Biocontrol Potential and Specificity of Entomopathogenic Fungi

Entomopathogenic fungi play an important role in insect–pest regulation in natural ways. Entomopathogenic fungi have a unique mechanism of action, high host specificity, and are being utilized as potential biological control agents to minimize the pest population. These fungi kill the insect through one or a combination of different mechanisms, with the production of various secondary metabolites such as ibotenic acid, destruxins, and tricholomic acid being one of them. These fungi infect and kill their hosts by suppressing the antioxidant defense systems of the insects. Several insect species of the Diptera, Coleoptera, Lepidoptera, Isoptera, and Hemiptera orders are susceptible to various fungal infections. Under the Integrated Pest Management system, different formulations of entomopathogenic fungi are being tested along with other management modules against crop pests and found to be compatible. Commonly, the strains of Beauveria bassiana, Beauveria brongniartii, Isaria fumosorosea, and Metarhizium anisopliae have been extensively explored for their biocontrol potential and are being used under field conditions to manage pests. These are broadly eco-friendly and have low to nil mammalian and residual toxicity without posing significant risks to nontarget organisms. Due to these reasons, entomopathogenic fungi have been regarded as biological insecticides against many insect pests. Considering the importance of entomopathogenic fungi, the different aspects, namely virulence, host specificity, antioxidant potential, compatibility, and histopathology, have been discussed in this chapter.