Selective activity of Carapa guianensis and Swietenia macrophylla (Meliaceae) against the corn and rice strains of Spodoptera frugiperda (Lepidoptera, Noctuidae)

Spodoptera frugiperda is a polyphagous pest with two strains (rice and corn strains). They differ in their insecticide susceptibility, providing an opportunity to discover new, bio-sustainable alternatives. Given the reported insect control potential of the Meliaceae family, the insecticide and antifeedant activity of Carapa guianensis and Swietenia macrophylla was assessed on both strains of S. frugiperda. Both plants had significant selective effects, and an extract of the twigs of S. macrophylla showed the most promising activity against the rice strain. In this regard, a moderate antifeedant effect, a high mortality rate in the insecticidal assay, and an alteration in metamorphosis, was observed. Characterization of this fraction led to the detection of phytosterols and fatty acids, and the isolation of β-sitosterol-3-O-β-glucopyranoside and stigmasterol.