Molecular Biopesticides: An Emerging Frontier for Managing Plant-Parasitic Nematodes

Plant-parasitic nematodes cause major yield and economic losses and remain difficult to manage because of their soil-borne nature, persistent biology, and broad host range. Conventional nematicides provide rapid suppression but face regulatory, safety, and environmental concerns, while cultural practices, biological control, and host resistance are constrained by variable field performance, durability, or breeding limitations. Molecular biopesticides, including double-stranded RNA (dsRNA), recombinant proteins/peptides, and characterized secondary metabolites, offer mechanism-based targeting of nematode genes, effectors, or essential pathways with greater specificity and potentially lower ecological footprints. This review summarizes advances in molecular biopesticides, including RNAi-based approaches (including host-delivered RNAi and exogenous dsRNA), with emphasis on dsRNA instability and nanocarrier-enabled protection, release, and uptake. It also examines nematotoxic proteins, engineered fusion constructs, and secondary metabolite-derived nematicides, highlighting the formulation and bioavailability challenges. Finally, target discovery, delivery platforms, efficacy evidence, biosafety considerations, field validation, manufacturing, and integrated pest management integration are also discussed.