Use of yellow mealworm (Tenebrio molitor) as a resource for the isolation, characterization and production-oriented development of microbial bioinsecticides: from basic science to applied research

The search for sustainable alternatives to chemical insecticides has renewed interest in microbial agents capable of suppressing insect pests. The yellow mealworm ( Tenebrio molitor ) is both a stored-product pest and an industrially reared insect for food and feed, yet its integrated role in microbial bioinsecticide research remains comparatively underexplored. This review evaluates T. molitor as a biological, experimental and production-aware resource for the isolation, characterisation and development of microbial bioinsecticide candidates based on viruses, bacteria and fungi. A bibliographic analysis identified 134 relevant articles, with a marked increase in publications during the last decade and a clear predominance of studies on entomopathogenic fungi. Viral research is recent and mainly linked to densoviruses, pathology and colony-health surveillance, although densovirus-based formulations indicate potential against mealworm as a stored-product pest. Bacterial studies have focused on toxin-mediated, septicemic and immune-related interactions, particularly involving Bacillus thuringiensis , other Bacillales and nematode-associated symbionts. Fungal studies represent the most developed area, with Beauveria and Metarhizium widely investigated for soil baiting, strain recovery, virulence screening, infection mechanisms and formulation-related performance. Overall, the evidence supports T. molitor as a tractable larval host with potential as a standardised platform for linking pathogen discovery, host-response assays and formulation-oriented microbial bioinsecticide research. Further progress will require standardised rearing and exposure protocols, microbiota-aware assays, clearer reporting of infection routes, target-pest validation and scalable formulation studies.