Entomopathogenic Fungi for Climate-Resilient Pest Management: A Critical Appraisal of Ecology, Formulation, Field Efficacy and Emerging Technologies

Abstract

Hypocrealean entomopathogenic fungi, chiefly species of Beauveria and Metarhizium, constitute the largest group of registered microbial agents for arthropod pest control. Their performance in the field depends on temperature, solar ultraviolet radiation and moisture, which are precisely the variables being reshaped by a changing climate. Recent reviews have addressed fungal ecology, mass production, endophytism and genetic improvement as largely separate literatures, and few have asked whether the combined evidence justifies dependable deployment under warmer, drier or more erratic conditions. This critical narrative review examines how abiotic constraints act at each step of the infection cycle, how production and formulation modify those constraints, what field and semi-field studies genuinely demonstrate, and how endophytic, genetic, nanotechnological and digital approaches might contribute to climatic robustness. Agricultural, acridid, disease-vector and livestock ectoparasite systems are considered; medicinal, nutraceutical and industrial applications of these fungi are excluded. Peer-reviewed literature was retrieved through structured searching of several international scholarly databases and indexes, extended by backward and forward citation tracking and by authoritative institutional sources, then appraised for design adequacy, environmental realism, scale and independent replication. Three conclusions are comparatively well supported. Ultraviolet radiation and low humidity act mainly by depleting or inactivating propagules on exposed surfaces, whereas temperature governs infectivity, virulence and speed of kill in both aerial and soil habitats. Oil-based formulations, polymer encapsulation and stress-conditioned or submerged-culture propagules measurably buffer these constraints, although the supporting evidence remains predominantly laboratory-derived. Large operational programmes against desert locust and sugarcane spittlebug indicate that fungal agents can perform reliably when strain, propagule, formulation and application timing are matched to local climatic conditions. Evidence for endophyte-mediated pest suppression and for endophyte-conferred abiotic stress tolerance in crops is markedly less consistent, and genetically enhanced strains have not advanced beyond contained or semi-field evaluation. The thermal performance of host and pathogen considered jointly, the translation of laboratory stress tolerance into field persistence, and the long-term ecological behaviour of improved strains remain inadequately characterised. Climatic resilience is better conceived as a property of the whole deployment system than of the fungus alone. Entomopathogenic fungi are therefore a credible but conditional element of climate-adaptive integrated pest management, and standardised multi-site field evaluation is now a more pressing need than further laboratory screening.