Highly virulent and specific biopesticides based on genetically modified entomopathogenic fungi

The use of entomopathogenic fungi represents a promising avenue in biological pest control against insect pests. This method offers significant advantages, including the ease of cultivating these fungi and their safety to non-target organisms, apart from insects. Nevertheless, a notable drawback of this approach is the relatively low virulence of entomopathogenic fungi towards insect hosts. This challenge can be addressed through genetic modification of the fungal strains. This review provides up-to-date insights into the development of novel biopesticides based on genetically modified strains and their potential applications in agriculture. The main methods of transformation of entomopathogenic fungi are polyethylene glycol-mediated transformation of protoplasts, transformation using agrobacteria, electroporation of germinated conidia and chemical transformation of blastospores. Incorporation of sequences encoding various effector molecules into the genomes of these organisms is a key strategy, allowing these fungi to negatively impact their infected insect hosts. Recent advancements have led to the creation of strains that secrete double-stranded RNA (dsRNA), targeting essential insect proteins, thus enhancing their virulence. Importantly, the enhancement of virulence in these strains is specific to particular pest insect species. Effective delivery of entomopathogenic fungi to target pests is crucial for the successful application of such biopesticides. Common methods include plant or soil drenching, foliar spraying, root or seed soaking, and the use of insect vectors. Soil drenching, for instance, selectively targets soil-dwelling insects, providing protection against environmental factors. For blood-feeding insects like ticks and mosquitoes, livestock and residential area spraying can be employed. This comprehensive overview sheds light on the genetic strategies for augmenting the insecticidal potential of entomopathogenic fungi and underscores the significance of effective delivery mechanisms for their successful utilization in integrated pest management strategies.