Can white fringetree serve as a refuge for emerald ash borer?

Emerald ash borer has devastated susceptible ash tree populations throughout eastern U.S. and Canada. In 2014, white fringetree was identified as an alternate host, albeit one that is more resilient in the face of emerald ash borer than most ash species. As such, white fringetree has the potential to serve as a refuge for emerald ash borer after susceptible ash species have been severely reduced or eliminated in an area. I followed emerald ash borer attack and impacts on a wild white fringetree population in southeastern Ohio throughout the invasion wave from 2015-2024. After an initial rapid rise and fall in beetle densities, attack rates, and impacts between 2016-2019, by 2024 most trees in the population were still alive, with 85% of them showing signs of historical attack by emerald ash borer. Twenty percent had current attack. Trees with attack showed greater amounts of canopy dieback than unattacked trees, but the multistemmed nature of the trees promotes tree resilience. All mature white ashes in the area were dead, although some smaller ash trees were still alive, but with signs of attack. Due to their moderate resistance and tolerance of emerald ash borer damage, white fringetrees can serve as a refuge for emerald ash borer, especially in large populations.