Botanical Pesticides Against Fall Armyworm in African Maize Systems: A Structured Narrative Review and SWOT Synthesis

Maize (Zea mays) production in Africa has been severely constrained by the fall armyworm (FAW), Spodoptera frugiperda, since the pest was first detected on the continent in 2016. Botanical pesticides are increasingly promoted as low-cost alternatives to synthetic insecticides, but the African evidence base remains scattered across plant species, formulations, experimental settings, and outcome measures. This study was conducted as a structured narrative review with an evidence-informed SWOT (strengths, weaknesses, opportunities, and threats) synthesis to evaluate the efficacy, field relevance, and practical limitations of botanical pesticides used against FAW in African maize systems. Literature published between 2016 and 2026 was identified through structured searches of Google Scholar and PubMed and was synthesized narratively because substantial heterogeneity in botanicals, extraction methods, doses, application methods, target stages, and study settings precluded meta-analysis. The review shows that Azadirachta indica currently has the strongest balance of laboratory-to-field support, while Tephrosia vogelii and Nicotiana tabacum remain promising but with conditional options because of chemotype dependence and phytotoxicity concerns. Essential oils expand the mechanistic scope of the evidence base but are still limited by volatility, weak persistence, and comparatively few field validations in African maize systems. Overall, botanical pesticides have credible potential within smallholder-oriented integrated pest management, but require standardisation, better field validation and clearer biosafety evidence, and more accessible formulations are needed before broad recommendation can be justified.