Ecological Management of Insect Pests in Rice (Oryza sativa L.) Using Refugia Plants and Biopesticides: A Case Study in Northern Sumatera, Indonesia

Abstract

This study evaluated the ecological management of insect pests in rice (Oryza sativa L.) through the integrated use of refugia plants (Zinnia elegans Jacq., Cosmos caudatus Kunth, Tagetes erecta L.), biopesticides (Carica papaya L. leaf extract, Cocos nucifera L., water, PGPR, and Beauveria bassiana), and control in Lubuk Bayas Village, Northern Sumatera, Indonesia. A total of 21 insect species from 13 families and 6 orders were recorded across both treatment and control plots. Rice fields incorporating refugia and biopesticides demonstrated significantly higher insect abundance (2,686 individuals) compared to control plots (1,678 individuals). Furthermore, these ecologically managed fields exhibited greater species richness (R′ = 0.29 vs. 0.14 in controls), greater evenness (E = 0.85 vs. 0.56 in controls), and increased diversity (H′ = 2.86 vs. 2.27 in controls). The results showed that the ANOVA test was not significant between the use of refugia, but was significant for biopesticide and control. These findings highlight the substantial potential of integrating refugia plants with biopesticides as a sustainable strategy to enhance insect biodiversity and foster ecological pest regulation within rice agroecosystems. Ultimately, this approach can contribute to improved rice productivity and strengthen national food security in Indonesia.