Oak wilt is caused by the exotic fungus, Ceratocystis fagacearum. The disease kills tens to hundreds of thousands of oak trees in the Midwest and Texas every year.
The fungus causes water-conducting xylem vessels to clog, leading to wilting and death of infected trees. The fungus can spread from infected to healthy trees through grafted roots.
The fungus is carried by certain species of sap beetles. If contaminated beetles land on fresh wounds (e.g. those resulting from storms or tree pruning), the tree will likely become infected.
Researchers at the Northern Research Station work to provide natural resource managers of state, county and urban forests with new or improved tools for integrated management of oak wilt.
Oak wilt studies have identified principal insect vectors, evaluated the efficacy of tree root crown injections with systemic fungicides, and the efficacy of root graft disruption (shown in the photo) to prevent the spread of the disease via root grafts. For more information, Jennifer Juzwik, a Research Plant Pathologist at the Northern Research Station.
Find research publications about oak wilt on Treesearch.