Climate change and the future distribution of Brown Planthopper in Indonesia: A projection study

The Brown planthopper, Nilapavarta lugens (Stål) (BPH) is a major pest of rice after the adoption of the Green Revolution. Its outbreaks are frequently linked to climate variability and change, posing almost all rice varieties in Indonesia at risk, resulting in economic losses due to reduced production. The amount of information available about its current and future potential distribution as well as the influencing factors are still limited. The objective of this study is to examine the impact of climate variability on BPH and to assess the projection of the BPH potential distribution under different climate scenarios. Maximum entropy (MaxEnt) was applied to predict the current and future potential distribution of BPH over Indonesia. This study used data on BPH-affected areas, rainfall and temperature, and the Ocean Nino Index (ONI) on a monthly interval to examine the linkage between climate and BPH affected areas. The global-climate models from phase 6 of coupled model intercomparison project (CMIP6) for period 2041–2060 were used to examine the variations in 19 bioclimatic variables for two shared socioeconomic pathways (SSPs) compared to baseline period (1971–2000). The findings concluded that the dynamics of BPH damaged areas were strongly influenced by higher temperature and rainfall in dry season associated with La Niña events. Precipitation of driest month, precipitation seasonality, mean temperature of driest quarter and temperature seasonality were the most affected factors in the distribution of BPH. Our results highlight BPH distribution was expected to increase to 2.4% and 3.02% (moderately suitable), 1.88% and 1.95% (suitable), 2.59% and 2.76% (highly suitable) respectively under SSP2-4.5 and SSP5–8.5. These findings could serve as early warnings to adjust agricultural practices and implement tailored pest management methods to effectively address the shifting pattern of BPH in the future.