Flavonoids as bio-insecticides: Harnessing plant metabolites as a biochemical shield against insects

The global decline in crop production poses a significant threat to food security, particularly in the context of a growing human population. Among various environmental constraints on agriculture, biotic stress, particularly that caused by insect pests, remains a major reason for yield losses. Traditionally, synthetic pesticides have been used to manage insect infestations; however, their excessive and non-targeted application has raised serious concerns regarding environmental pollution, adverse health effects, and the accelerated development of pesticide-resistant pest populations. In this context, plant-derived biocactive compounds, particularly flavonoids, have emerged as promising bioinsecticides due to their potent insecticidal properties. Flavonoids, a diverse group of secondary metabolites found abundantly in plants, exhibit strong insecticidal activity by disrupting insect digestion, interfering with nutrient absorption, and inhibiting growth and metamorphosis. These bioactive compounds act through multiple mechanisms, reducing the likelihood of resistance development while offering an eco-friendly alternative to conventional chemical pesticides. Additionally, flavonoids contribute to integrated pest management strategies by enhancing plant defence responses and synergising with other bioinsecticides. Despite their potential, research on flavonoid-based insect control remains limited, particularly in terms of their formulation, stability, and large-scale applicability. Further studies are needed to investigate their interactions with insect physiology, optimise delivery methods, and assess their environmental impact. Advancing flavonoid-based bioinsecticides can contribute significantly to sustainable pest management in modern agriculture, reducing dependence on synthetic pesticides while preserving ecosystem balance. This review examines the potential role of flavonoids as biopesticides in pest management, highlighting the existing research gaps and prospects.