Entomopathogenic Fungi as Microbial Biocontrol Agent

Abstract

An attractive alternative method to chemical pesticides is the microbial biocontrol (MBCAs) agents. They are the natural enemies devastating the pest population with no hazard effects on human health and the environment. Entomopathogenic fungi has an important position among all the biocontrol agents because of its route of pathogenicity, broad host rang and its ability to control both sap sucking pests such as mosquitoes and aphids as well as pests with chewing mouthparts, yet they only cover a small percentage of the total insecticide market. Improvements are needed to fulfill the requirements for high market share. Entomopathogenic fungi differ from other microorganisms in their infection process: they directly breach the cuticle to enter the insect hemocoel, while other microorganisms enter by ingestion through mouth and then cause disease. Insect cuticle is mainly composed of chitin and protein surrounded by wax, lipid layer or fatty acids. Fungal pathogenesis mainly starts with the secretion of cuticle degrading enzymes. Some important and well known cuticle degrading enzymes are chitinase, protease and lipase which can degrade chitin, protein and lipid of the cuticle, respectively. In this review we collected literatures from different sources and we arranged them in a such a way to better to understand the process of insect pathogenicity of entomopathogenic fungi and to find ways to improve the virulence of wild strain fungi to shorten the killing time of the pest and to commercialize the entomopathogenic fungi. In this way, the market share of the fungal entomopathogenic fungi will increase and a decrease in the usage of synthetic chemical pesticides will automatically follow.