Predator communities associated with Spodoptera exigua in tropical shallot agroecosystems

Spodoptera exigua Hübner is a major pest of shallot (Allium ascalonicum L.) that can significantly reduce productivity in tropical agroecosystems. Pest control in shallot cultivation still relies heavily on synthetic insecticides, which may lead to pest resistance and negatively affect natural enemy populations. This study identified predator communities associated with S. exigua in tropical shallot agroecosystems in Bangli Regency, Bali, Indonesia. Field observations were conducted in four shallot-producing villages (Trunyan, Buahan, Kedisan, and Songan) from June to September 2025. Predator abundance, pest population, and infestation levels were analyzed using ecological indices including Shannon diversity (H′), evenness (E), species richness (R), and dominance (D). Seven predator groups were identified, with moderate to high diversity (H′ = 1.51–1.77) and high evenness (E > 0.78). Predator abundance showed a strong negative correlation with S. exigua population (r = −0.76; R² = 0.58). These results highlight the importance of predator conservation in sustainable integrated pest management for tropical shallot production.