Predicting climate change impacts on potential distribution of cashew stem and root borer Neoplocaederus ferrugineus in India based on CMIP6 projections

Cashew stem and root borer (CSRB) Neoplocaederus ferrugineus is the most dreaded insect pest of cashew, and its damage results in death of trees. Monitoring and spread of CSRB assume greater importance since it is an economically important pest, and the distribution potential of N. ferrugineus in India is unknown under present and future climate change. The recent Coupled Model Intercomparison Project phase 6 (CMIP6) dataset was analysed to predict the distribution potential of CSRB under current and future (2050 and 2070) considering two distinct emission scenarios namely shared socioeconomic pathway (SSP) 126 and SSP585 through MaxEnt modelling approach. Habitat suitability of N. ferrugineus was mainly driven by temperature and precipitation-based variables contributing 95.5% of the potential distribution. Jackknife test results showed that temperature seasonality (BIO4; 39%), annual precipitation (BIO12; 28.8%) followed by annual mean temperature (BIO1; 17.3%) and mean diurnal range (BIO2; 10.4) were the significant predictors contributing to the potential spread of CSRB. The entire coastal, peninsular India and parts of Northeastern states are forecasted with higher suitability for CSRB colonization. The MaxEnt model estimated an increase of 20.75% area suitable for the spread and establishment of N. ferrugineus under projected climate change. Our predictions highlighted that habitat suitability and potential distribution of CSRB would increase in 2050 and 2070 under SSP585 scenario. Prediction of major bioclimatic variables and habitat suitability areas will be instrumental to monitor and forecast the potential spread of N. ferrugineus in cashew and facilitate the researchers, policymakers, and extension workers to develop effective pest management strategies well in advance.