BIOLOGICAL CONTROL OF AGRICULTURAL INSECT PESTS: PARASITOIDS, PREDATORS, ENTOMOPATHOGENIC FUNGI, AND MICROBIOME-MEDIATED SUPPRESSION IN INTEGRATED PEST MANAGEMENT SYSTEMS

Abstract

Agricultural insect pests account for pre-harvest crop losses estimated at 10 to 40% globally, representing a critical threat to food security for an expanding human population. The near-exclusive reliance on synthetic insecticides for pest management has generated pervasive problems including the evolution of insecticide resistance, disruption of non-target organisms, environmental contamination, and escalating economic costs to farmers. Biological control, the deliberate exploitation of natural enemies including parasitoids, predators, entomopathogenic fungi, and microbiome-based agents, offers a sustainable alternative and complement to chemical pesticides within Integrated Pest Management (IPM) systems. This review synthesizes current knowledge on four principal categories of biological control agents, examining their mechanisms of action, host specificity, efficacy under field conditions, commercial development status, and compatibility within IPM frameworks. We highlight the emerging frontier of microbiome-mediated pest suppression, including the roles of plant microbiomes in induced resistance, insect gut microbiome disruption as a biocontrol target, and synergistic interactions between microbial biocontrol agents. Key challenges including inconsistent field performance, regulatory barriers, climate change impacts, and non-target effects are critically evaluated. We identify priority research directions including omics-assisted biocontrol agent discovery, nanotechnology-enhanced delivery, and AI-driven precision deployment, and conclude with recommendations for accelerating the adoption of biological control within sustainable agricultural systems.