Comprehensive assessment of Erwinia amylovora: from establishment risk in global host production areas to dispersal dynamics and associated economic losses in China

Ming LiXiaoqing XianZhenan JinYuhan QiJianyang GuoNianwan YangGuifen ZhangJin Xu^*Wanxue Liu^*

• Chinese Academy of Agricultural Sciences State Key Laboratory for Biology of Plant Diseases and Insect Pests, Beijing, China

Erwinia amylovora is the bacterial pathogen that causes fire blight and is considered one of the most important plant pathogenic bacteria in the world, posing a serious threat to pear and apple production. However, most of the current risk assessment studies have focused primarily on the potential geographic distribution of E. amylovora, with less focus on its dispersal patterns, dispersal risk areas, and economic impacts. Here, species distribution models, minimum cost arborescence approach, the MigClim package, and Monte Carlo stochastic simulations were integrated to comprehensively assess the global establishment risk, local dispersal patterns, dispersal risk areas, and economic losses for E. amylovora. The results showed that E. amylovora was primarily distributed in North America, southern South America, Europe, northern and southern Africa, western and eastern Asia, and southern Oceania under near-current climatic conditions. In addition, the overlapping distribution area of E. amylovora and the host production area is 1897.62 × 10⁴ km², mainly located in central North America, southern South America, Europe, northern Africa, eastern and western Asia, and southern Oceania. Its global distribution and the overlapping area are expected to expand further under future climatic conditions. The E. amylovora shows primarily "leap-frog" long-distance spread in China, and the dispersal risk area is mainly in northwestern China. The economic losses caused by E. amylovora to the host industry amounted to 5603.66 million dollars without any control measures, however, 2390.13 million dollars can be saved after control measures. Such comprehensive risk assessments provide global guidance for monitoring and controlling E. amylovora in host production areas, while also helping to formulate management priority strategies in local dispersal risk areas, thereby reducing economic impact.