The frequency of EAB outbreaks in China have increased since the 1960s
Data from historical literature reveal no records of EAB outbreaks on ash trees prior to 1960. The first reported outbreaks of EAB occurred on green ash in Heilongjiang and Liaoning Provinces is 1961 and 1963 respectively. The total number of cities and provinces with EAB outbreaks has increased each decade since 1961 (Table 1). By the 2010s, EAB was detected in Xinjiang-Uygur Autonomous Region and Shandong Provinces, where it caused substantial damage to exotic ash trees (green, white, and velvet ash). To date, EAB has spread to eight provinces, provincial cities, or regions in northeastern, northern and northwestern China and the numbers of cities with EAB outbreaks has increased 10-fold (Table 1).