Soil Predatory Mites and Microbe-Mediated Biocontrol: Advancing Sustainable Pest Management in Agricultural Systems

Biological control of soil-borne pests represents a critical ecosystem service that sustains soil and plant health. Soil ecosystems harbor complex food webs, in which microfauna, such as nematodes and protists, regulate microbial communities and drive nutrient mineralization, supporting above-ground productivity. Soil predatory mites, commonly known as Acarine Biocontrol Agents (ABA), function as trophic-level omnivores, exerting top-down control on nematodes and other invertebrates, while benefiting from bottom-up support through free-living nematodes (FLN) that graze microbial communities. These predator–prey interactions enhance mite fitness by providing essential biomolecules, including ω3 long-chain polyunsaturated fatty acids, which improve developmental rates, reproductive performance, and biocontrol efficiency. Plant Growth-Promoting Bacteria (PGPB) complement ABA-mediated biocontrol by producing phytohormones, siderophores, nematicidal compounds, and inducing systemic resistance, thereby directly and indirectly suppressing plant-parasitic nematodes. Conservation biological control (CBC) strategies that maintain functional soil food webs through minimal disturbance, organic amendments, and cover crops are pivotal for sustaining ABA and PGPB populations. Moreover, soil physical structure, organic matter content, and chemical environment influence predator mobility, prey accessibility, and microbial activity, further shaping biocontrol outcomes. Emerging soil threats, including microplastics, heavy metals, and radioactive contamination, disrupt these interactions, emphasizing the need for integrated management approaches. Overall, understanding complex trophic interactions and microbe-mediated mechanisms provides a framework for designing sustainable, multifunctional soil management strategies that enhance ecosystem resilience and agricultural productivity.