Valorization of horticultural by-products as sources of natural agents for biological control of disease vectors

Synthetic pesticides are widely used for disease vector control, but their repeated application poses risks to human health, environmental quality, non-target organisms, and may contribute to pesticide resistance. These limitations have increased the need for safer, sustainable, and locally available alternatives. Horticultural wastes, including fruit peels, seeds, pulp, leaves, pruning residues, and processing by-products, represent an abundant and underutilized source of bioactive compounds with potential for vector management. However, existing evidence is fragmented across different waste sources, bioactive constituents, target vectors, mechanisms of action, and application technologies, highlighting the need for an integrated assessment of their potential and practical limitations. This review synthesizes current knowledge on horticultural by-products as natural vector-control agents, with emphasis on their bioactive compounds, mechanisms of action, efficacy, extraction and formulation technologies, environmental considerations, and future applications. Citrus wastes have received considerable attention because of their strong larvicidal activity associated with limonene, citral, and other terpenoids. Pomegranate peel, mango waste, grape pomace, and garlic residues also show promising activities due to their polyphenols, tannins, sulfur-containing compounds, and other metabolites. The review further identifies key research gaps, including the need for standardized extraction and formulation methods, field validation, safety assessment, and evaluation of long-term efficacy. Finally, region-specific utilization of horticultural and agricultural residues is proposed as a promising strategy for developing sustainable and economically viable vector-control products while supporting waste valorization and circular bioeconomy approaches.