Oak Wilt

Oak wilt is a lethal disease of oaks (Quercus spp.) caused by the fungus Bretziella fagacearum.  This disease is prevalent throughout the eastern U.S., and is the most serious on trees in the red oak family (e.g. red oak, black oak, pin oak, etc.).  Fungal mats can form beneath the bark surface of infected trees, and these sweet-smelling mats can attract nitidulid beetles.  The beetles can then spread fungal spores to other trees, or the fungus can spread tree-to-tree via root grafts.  Proper diagnosis is key to oak wilt management, and once diagnosed a number of management options are available.  These options include direct control via trenching to sever root grafts, fungicides, or planting resistant trees.  Prevention is the most effective management option - specifically, avoid pruning oak trees during spring.