Projected changes in climate suitability for the Brown Planthopper (Nilaparvata lugens) in West Java under future climate scenarios

Department of Geophysics and Meteorology, Faculty of Mathematics and Natural Science, IPB University, Bogor, 16680, Indonesia

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Abstract

One of the impacts of climate change in the agricultural sector in Indonesia is the shift in the distribution of the brown planthopper (Nilaparvata lugens), a significant threat to rice cultivation in Indonesia. This study provides one of the first CLIMEX-based assessments of brown planthopper climatic suitability in West Java using multi-model CMIP6 projections and spatial autocorrelation analysis. Baseline (1990-2020) and future climate conditions (2040-2060) were simulated under the SSP2-4.5 and SSP5-8.5 scenarios using four CMIP6 models (ACCESS-CM2, EC-Earth3-Veg, GISS-E2-1-G, and HadGEM3-GC31-LL). Climatic suitability was quantified using the Ecoclimatic Index (EI), while spatial clustering was evaluated using Moran's statistics. Under baseline conditions, high-suitability zones (EI 51-75) are predominantly concentrated along the northern coastal regions, especially in Indramayu, Karawang, and Subang. Under future scenarios, suitable areas expand southward and into middle-altitude regions, increasing from approximately 40% at present to nearly 80% under SSP5-8.5. Spatial analysis indicates significant clustering of suitability across neighboring districts. These findings indicate that rising temperatures increasingly support brown planthopper development, thereby elevating pest risk in major rice-producing areas of West Java.