The Sustainable Use of Syringa (Melia azedarach L.) as a Botanical Pesticide in Small-Scale Farming Systems—An Integrated Review

Achieving sustainable agriculture requires environmentally friendly alternatives to synthetic insecticides. Hence, this review seeks to evaluate the sustainable use of syringa as a botanical pesticide in small-scale farming systems. The review applied an integrated literature review framework to synthesize published work on Melia azedarach L. use in insect pest control. Peer-reviewed and grey literature were sourced from multiple databases and repositories using defined keywords. No lower time limit was applied, and literature coverage included published work up to 2026. After screening 159 records, 99 studies were retained and thematically grouped into eight areas: botanical description, distribution, biopesticides and their mode of action, botanical insecticides and their benefits, Melia. azedarach L. as a botanical insecticide, the limitations on the usage of plant-based extracts and the effects of different extraction methods on the efficacy of Melia azedarach L. extracts. A narrative synthesis highlighted key findings, contradictions, and knowledge gaps while noting potential biases, including English-only sources. Studies indicate that Melia azedarach L. exhibits multiple modes of action, including repellency, antifeedant activity, oviposition deterrence, growth inhibition, ovicidal and larvicidal effects, and suppression of adult emergence. Despite challenges such as variability in extract composition, limited field standardization, and short residual activity, Melia azedarach L. shows considerable potential as a sustainable component of integrated pest management for small-scale farming. Future research should focus on standardized extraction protocols, field validation, formulation development, and commercialization to enhance adoption.