How does oak wilt spread?
Oak wilt spreads long distances with the aid of sap-feeding (Nitidulid) beetles. These beetles are about the size of the ball on the end of a straight pin. They are attracted to fungal mats that form underneath the bark of diseased red oaks. The fungal mats produce spores and have a ridge down the center that lifts the bark creating a tiny crack. Insects are attracted to this opening because the mat has a fruity smell. These mats can be found all over the trunk and major branches. The Nitidulid beetles after feeding on the mats fly off. If a contaminated beetle lands on a fresh wound on a healthy oak then that tree can become infected. It does not matter how the wound was made whether with a chainsaw, by wind damage, or the bumper of the car. Once established, the fungus moves from one tree to the next through common or grafted roots.
