Potential economic impact of Bactrocera dorsalis on Chinese citrus based on simulated geographical distribution with MaxEnt and CLIMEX models

Climate change and global trade are two main drivers of shifts in the distribution of invasive insect pests. The Oriental fruit fly, Bactrocera dorsalis Hendel, is one of the most economically important invasive pests having detrimental effects on several vegetables and fruits. This highly invasive species originating from mainland Asia has now spread worldwide. The species has recently expanded its range northward into previously considered unsuitable areas such as Central China, which poses a significant new risk to agriculture in the temperate zone. In this study, we identified the limiting climatic conditions in the global distribution area. We combined MaxEnt and CLIMEX models to estimate the suitable areas of B. dorsalis under climate change scenarios. Moreover, the potential economic impact of B. dorsalis was predicted for citrus in China, with and without management practices, using the Monte Carlo simulation model. Results showed that current climatically suitable locations included parts of central and southern North America, north and east of South America, central Africa and Madagascar, east, south, and Southeast Asia, and northern Oceania. MaxEnt and CLIMEX predictions indicated that the suitable area of B. dorsalis would expand northward in North America and southward in South America under future climatic conditions. In China, the potential geographical distribution of B. dorsalis would expand northward into Henan, Shandong, and some parts of Hebei. Moreover, @RISK software analysis showed that B. dorsalis could cost the citrus industry in China 25.21 billion US dollars without management practices. These management measures would save 8.721 billion US dollars. These results provide in-depth information about the impact of climatic changes on the possible geographic range of B. dorsalis and its impact on the citrus industry in China.