Quantifying the Spread and Economic Consequences of the Codling Moth (Cydia pomonella) in China Using Biomod2 and Monte Carlo Synergy

The codling moth, Cydia pomonella (Linnaeus, 1758) (Lepidoptera: Tortricidae), was first detected in Xinjiang, China, in 1953 and has since spread to nine provinces, with its distribution continuing to expand into other apple- and pear-producing regions. In this study, we combined the Biomod2 model with Monte Carlo simulations to perform a spatially explicit, pixel-level assessment of the moth’s potential habitat suitability and associated economic impacts in China’s major fruit-producing areas. Results indicate that temperature is the primary factor limiting its distribution, followed by human activities, while topography plays a regulatory role at local scales. The Loess Plateau and Bohai Rim regions were identified as core suitable areas, with moderate suitability in the Northern Cold region and Xinjiang and lower suitability in the Southwest and Yangtze River Basin. Pearson correlation analysis revealed weak spatial coupling between suitable habitats and fruit yields. Monte Carlo simulations showed that potential economic losses vary spatially across regions and crop types. These findings suggest that the codling moth’s suitability differs among regions; high-yield areas do not necessarily face higher invasion risk, but once an invasion occurs, economic losses tend to be concentrated and severe. Accordingly, early warning and region-specific, differentiated management should be prioritized in key areas to mitigate damage.