Bottom-up effects of host plant colonization with endophytic entomopathogenic fungus strengthen the predator-driven top-down control of a pest

• Dual biocontrol agents strengthen pest suppression, minimizing chemical use and pest resistance. • T. urticae fitness declined under P. persimilis and endophytic M. anisopliae pressure. • Entomopathogenic fungus did not hinder predator population growth. • Predators preferred preys on fungus-colonized plants, increasing predation capacity. • Both agents were compatible and acted compatibly for stronger control of T. urticae . Micro- and macro-biological control agents are key components of integrated pest management (IPM), reducing reliance on hazardous chemical pesticides and ensuring environmental sustainability. However, each agent by itself often provides limited pest suppression. Since entomopathogenic fungi (EPF) can attract predators when established endophytically, combining both agents may improve control, though evidence remains limited. This study examined the population growth of the globally destructive and polyphagous arthropod pest Tetranychus urticae on tomato ( Solanum lycopersicum ) plants endophytically colonized with the broad-spectrum entomopathogenic fungus Metarhizium anisopliae through spraying its lower leaves, and assessed life table parameters, predation potential, and preference of its key and well-known predator Phytoseiulus persimilis using prey reared on colonized, non-sprayed leaves. Results indicated that most life table parameters of T. urticae , particularly the intrinsic rate of increase ( r ), were significantly lower on colonized, non-sprayed leaves than on control ones. Conversely, the intrinsic rate of increase ( r ) did not differ significantly between predatory mites fed on prey from colonized non-sprayed leaves and those from control leaves. In contrast, the predator exhibited a higher preference and consumption rate for fungus-affected prey resulting in a significantly higher finite predation rate. Overall, the bottom-up leverage of the endophytic entomopathogenic fungus and the top-down pressure exerted by the predatory mite were both compatible and complementary, thereby promoting safe and efficient pest management within a dynamic multi-trophic system.