Predicting future habitat suitability of the Khejri root borer, Acanthophorus serraticornis (Oliver) under CMIP6 climate projections

Climate change is increasingly influencing the distribution and dynamics of insect pests, particularly in fragile arid and semi-arid ecosystems. This study evaluates the current and future climate-driven habitat suitability of Acanthophorus serraticornis, a destructive wood-boring pest associated with Khejri (Prosopis cineraria) ecosystems in Rajasthan, India. Species distribution modelling was performed using climatic predictors to assess environmental controls on species occurrence and to project potential distribution shifts under future climate scenarios. A total of 108 field occurrence points and nineteen bioclimatic variables were used, with model performance assessed through repeated cross-validation, yielding a high mean AUC value of 0.994. Precipitation seasonality (42.6%), annual mean temperature (35.1%), and isothermality (20.3%) were identified as key predictors influencing habitat suitability. Response curves indicated a preference for warm and relatively dry conditions. Under current climate conditions, moderate to very high habitat suitability covers approximately 40–55% of the study area, mainly in central, western, and south-western Rajasthan. Future projections under SSP2-4.5 and SSP5-8.5 scenarios for 2050 and 2070 indicate progressive habitat fragmentation and overall decline in suitability. Suitable habitat is projected to decrease by approximately 20–50% under SSP2-4.5 and 40–70% under SSP5-8.5, with highly suitable areas declining to less than 10–15% by 2070 under SSP5-8.5. Change detection suggests that over 60–90% of the region may experience moderate to strong declines, with limited refugia persisting. These findings provide insights for climate-resilient pest monitoring and management in arid forest ecosystems.