Exploitation of Nomuraea rileyi and Beauveria bassiana for the management of lepidopteran pests.

Abstract

Pest management in agriculture started leaning towards biocontrol options for increasing agricultural production, sustaining the health of farmers and environment. Entomopathogenic fungi are potential biocontrol agents due to their infectivity by contact unlike bacteria or viruses which infect after ingestion. Nomuraea rileyi (Farlow) Samson and Beauveria bassiana (Balsamo) Vuilemin are potentially versatile fungi because of their wide spread occurrence, broad host ranges, ability to infect at different stages of their hosts and cause natural epizootics on major lepidopteran pests. Recent advances in large-scale in vitro production, formulation and application technology have resulted in commercial availability of several mycoinsecticide products based on B. bassiana and N. rileyi. These formulations provide good control of pests and are being used as biocontrol agents in various crop ecosystems with minimal effects on non-targets. Combination formulation of B. bassiana and Bacillus thuringiensis lowered the dose requirement and improved the speed of kill. Improving our understanding on the mode of action of the fungi at cellular and molecular level, exploiting secondary metabolites of the fungi to develop natural insecticides, refinement of formulation and application technology, and use of nanotechnology for improved delivery and persistence will enable us to utilize these fungi more effectively as well as economically under varied agro-climatic conditions. This chapter brings together the information generated on various aspects of N. rileyi and B. bassiana, their biocontrol potential in insect pest management as mycoinsecticides, registration requirements and regulatory approaches for commercial exploitation of these entomopathogenic fungi.