Pest Control Strategies Using Secondary Metabolites of Entomopathogenic Fungi

The chapter discusses the use of entomopathogenic fungi to control insect pests, highlighting benefits such as reduced pesticide residues and increased biodiversity. Research suggests combining strategies for more efficient pest management and reduced pesticide use. The intricate relationships between insects and microorganisms, especially symbiotic bacteria in insect microbiomes, are under investigation. Various mechanisms used by these microorganisms to control fungi, including the production of antifungal compounds and extracellular enzymes, are being explored. Molecular evolution has unveiled the complexity of their classification, exposing multiple cryptic species and genetic diversity. The text also explores the utilization of entomopathogenic fungi, such as Beauveria bassiana and Metarhizium anisopliae, as biological control agents against pests, specifically Scyphophorus acupunctatus, also known as the agave weevil, which is a common pest infesting agave crops in Mexico. Studies show the effectiveness of infecting and killing both larvae and adults of S. acupunctatus. Native strains of B. bassiana and Metarhizium sp. Researchers from Oaxaca, Mexico, have shown that the pathogens are pathogenic against adult S. acupunctatus, causing over 70% mortality. These fungi offer advantages over synthetic insecticides, such as specificity in targeting insects, safety for humans and vertebrates, and disruption of insect life cycles. In addition, the paper explores the taxonomic complexity and morphological characteristics of the genus Lecanicillium, highlighting its global distribution and diverse ecological roles as a mycoparasite and endophyte. The potential of Lecanicillium as a biological control agent against various pests, including aphids, whiteflies, and bed bugs, is discussed. Similarly, the mechanisms of action of Trichoderma, another biological control agent against pests and pathogens, are reviewed, and several secondary metabolites with fungicidal properties are synthesized. It also discusses various methods for the mass production of entomopathogenic fungi (EPF) used in agriculture, such as in vivo production, diphasic fermentation, submerged fermentation, and stirred tank bioreactors. The effectiveness of these methods in producing EPF is highlighted, with examples such as B. bassiana and Clonostachys rosea showing promising results in controlling pests such as Spodoptera frugiperda and Anticarsia grandis. Finally, the importance of optimizing operating conditions in stirred tank bioreactors to maximize conidial production is highlighted. The study of entomopathogenic fungi, their secondary metabolites, and their efficacy in pest control represents a research frontier with immense potential. It promises improvements in agricultural practices and offers environmentally friendly solutions to pest problems.