Climate and host plant drive the distribution of a specialist moth, Rhodostrophia jacularia (Geometridae), in the Central and Northeastern Asia

The responses of species inhabiting arid regions to climate change, characterized by rising temperatures and increasing precipitation variability, remain poorly understood. In this study, we applied a maximum entropy model (MaxEnt), incorporating the predicted distribution of the host plant Goniolimon speciosum, to assess the current and future suitable distribution of Rhodostrophia jacularia. We evaluated the combined influence of climate change and host plant availability on the moth’s distribution. Both models showed high predictive performance (AUC > 0.90), indicating robust predictions. Host plant distribution was the most important factor shaping the moth’s range, followed by precipitation variables. Under current climatic conditions, suitable habitats for R. jacularia extend across Mongolia, northern China, southern Russia, and northeastern Kazakhstan. Future projections indicate a contraction and westward shift in suitable habitats, with habitat losses of 31.87% under SSP126 and 38.94% under SSP585. The current overlap between the moth and its host plant covers approximately 1,912,177 km² but is projected to decrease to 736,451 km² (SSP126) and 528,480 km² (SSP585). These findings highlight the vulnerability of R. jacularia to climate change and emphasize the importance of incorporating biotic interactions into species distribution models to improve conservation planning.