Seasonal and Year-Round Distributions of Bactrocera dorsalis (Hendel) and Its Risk to Temperate Fruits under Climate Change

SIMPLE SUMMARY: The oriental fruit fly Bactrocera dorsalis (Hendel) is a pest species in the Tephritidae family that damages many fruits and vegetables. Dispersal of B. dorsalis is mediated by human activities (e.g., trade) and climate change, and it can cause serious damage to crops in newly invaded regions. Previous studies mainly focused on the areas potentially suitable for year-round reproduction, but it is unclear where the seasonal and year-round suitable areas are in the world. We used ecological niche models to predict the potential seasonal and year-round distribution areas of B. dorsalis. Bioclimate factors contributed differently to these two kinds of distributions. In the future, the areas suitable for B. dorsalis will increase, and the range will likely expand northward from existing locations. The spread of B. dorsalis in the seasonally suitable areas could threaten the production of some temperate fruits, including apples, peaches, pears, and oranges. ABSTRACT: Bactrocera dorsalis (Hendel) is an important pest to fruits and vegetables. It can damage more than 300 plant species. The distribution of B. dorsalis has been expanding owing to international trade and other human activities. B. dorsalis occurrence is strongly related to suitable overwintering conditions and distribution areas, but it is unclear where these seasonal and year-round suitable areas are. We used maximum entropy (MaxEnt) to predict the potential seasonal and year-round distribution areas of B. dorsalis. We also projected suitable habitat areas in 2040 and 2060 under global warming scenarios, such as SSP126 and SSP585. These models achieved AUC values of 0.860 and 0.956 for the seasonal and year-round scenarios, respectively, indicating their good prediction capabilities. The precipitation of the wettest month (Bio13) and the mean diurnal temperature range (Bio2) contributed 83.9% to the seasonal distribution prediction model. Bio2 and the minimum temperature of the coldest month (Bio6) provided important information related to the year-round distribution prediction. In future scenarios, the suitable area of B. dorsalis will increase and the range will expand northward. Four important temperate fruits, namely, apples, peaches, pears, and oranges, will be seriously threatened. The information from this study provides a useful reference for implementing improved population management strategies for B. dorsalis.