Oak wilt is a fungal disease caused by the organism Bretziella fagacearum that threatens Quercus spp. The disease is limited to the eastern half of the United States; first described in the 1940s in the Upper Mississippi River Valley. The pathogen penetrates xylem tissue, preventing water transport and causing disease symptoms. Symptoms generally consist of leaf discoloration, wilt, defoliation, and death. The disease is dispersed by insect vectors and to adjacent trees through underground root networks. However, human spread is the most consequential dispersal method. Moving firewood long distances can potentially transport diseases and invasive species. Disease Oak wilt is a devastating exotic disease, killing some trees rapidly in a single season. Oak wilt is an important disease in urban areas where trees are highly valued. The disease reduces property values because of the loss of trees and is economically costly to the property owner since they or the local government must pay for tree removal. Additionally, preventing the spread of the disease to healthy trees is costly and requires vigilance. Oak wilt is also an important disease in a forest setting, as entire forest stands can die within a few years. There is a narrow window to salvage diseased trees for hardwood lumber and often the disease is not discovered within that logging window. The ecological impacts to forests is also a concern. The disease is currently restricted to North America, but is potentially a serious threat to oaks worldwide. All Quercus spp. appear susceptible to the disease, with 33 oak species confirmed to be susceptible; including three species of Castanea, one species of Castanopsis, one species of Lithocarpus, and some oaks native to Europe (Q. petraea, Q. pubescens, & Q. robur). Generally, red oaks (subsection Lobatae) display more severe symptoms with rapid and frequent mortality (particularly Q. velutina, Q. rubra, Q. ellipsoidalis & Q. coccinea). White oaks (subsection Quercus) develop symptoms more slowly, rarely die, and can recover from the pathogen with damage limited to a few branches (particularly Q. alba, & Q. macrocarpa). Live oaks (Q. fusiformis & Q. virginiana) display intermediate symptoms compared to red or white oaks. However, live oaks are semi-evergreen, can propagate vegetatively by root suckering, and cohabitate with other live oaks in dense stands enabling interconnected root systems. These traits are favorable for local spread of the disease in an oak-grassland savanna. History Oak wilt is one of three devastating North American