Untargeted metabolomics-based study of extracts from Simarouba glauca plant parts for insecticidal effects against Spodoptera frugiperda

The Fall armyworm (Spodoptera frugiperda) presents a major challenge to global maize production. This study evaluates the insecticidal potential of Simarouba glauca extracts as an eco-friendly alternative to synthetic pesticides. Bioactive compounds were extracted from different plant parts using various solvents, with seeds yielding the highest recovery in n-hexane, while the bark extracted with ethyl acetate exhibited the lowest median lethal concentration (LC₅₀) of 4.80%. Antifeedant assays demonstrated that cold-pressed seed oil achieved over 52.3% feeding inhibition at elevated concentrations. Gas chromatography-tandem mass spectrometry identified key metabolites, including gamma-sitosterol and lanosta-8,24-dien-3-one, with distinct metabolic signatures in bark extracts, as revealed by principal component analysis and clustering techniques. Transcriptomic analysis using RNA sequencing and differential gene expression profiling identified 734 genes with significant expression changes, implicating disruptions in metabolic and signaling pathways associated with insect mortality and feeding deterrence. Molecular docking studies targeting cytochrome P450 and odorant-binding proteins confirmed strong ligand interactions, suggesting interference with detoxification and chemosensory functions. Our findings suggest S. glauca as a viable natural alternative to synthetic pesticides, paving the way for future research into its bioactive compounds for pest management strategies that support ecological and agricultural sustainability.