Ethnobotanical validation of plant extracts for sustainable management of fall armyworm

Abstract

Abstract. Labonete HJP, Ancheta DJ, Modina RMR, Yongco JE, Torres MAJ, Demayo CG. 2025. Ethnobotanical validation of plant extracts for sustainable management of fall armyworm. Asian J Ethnobiol 8: 222-229. Ethnobotanical practices offer essential insights for pest management in smallholder farming. In the Philippines, the use of chili (Capsicum frutescens), madre de cacao (Gliricidia sepium), and lemongrass (Cymbopogon citratus) as botanical insecticides is based on farmers' knowledge and indigenous traditions, yet their effectiveness against transboundary crop pest fall armyworm (Spodoptera frugiperda) remains untested. To address this gap, the sublethal effects of crude botanical extracts on third-instar S. frugiperda larvae were studied under laboratory conditions. All extracts produced dose-dependent sublethal effects: lemongrass caused the strongest feeding suppression (28.7%) and induced developmental malformations in larvae (5.0%), pre-pupae (6.3%), pupae (14.3%), and adults (7.1%); chili delayed development by up to 7 days and reduced survival to 45%; and madre de cacao deterred feeding mainly in dual-choice assays (antifeedant index=49.2%), suggesting efficacy for intercropping. This is the first validation of crude aqueous extracts for S. frugiperda, demonstrating the potential of farmer-based botanical insecticides as an addition to integrated pest management (IPM). The findings highlight how locally adapted practices, grounded in ancestral and community knowledge, can contribute to agroecology and strengthen food security by advancing sustainable, low-cost, and eco-friendly alternatives to synthetic pesticides. However, to fully realize this potential, further field-based trials and phytochemical characterization are crucial and should be the focus of future research.