Biopesticides are crop protection products based on living micro-organisms or natural products. Microbial biopesticides have a history of use in the biological control of insect pests and include bacteria [mainly various strains of Bacillus thuringiensis (Bt)], entomopathogenic fungi (e.g., Beauveria bassiana and Metarhizium species), numerous species of baculovirus, and also entomopathogenic nematodes. Biopesticides are a valuable emerging tool with tremendous promise for controlling challenging insect pests and ENDORSE aims to improve the efficacy of selected entomopathogenic fungal biopesticides whilst safeguarding the long-term resistance management of these products.