We refer to this symptom as veinal necrosis (death of the vein) and it is considered diagnostic, Other symptoms include tip browning and leaf margin browning. Oak Wilt Transmission. Leaf symptoms of oak wilt on Live Oaks are distinctive. On live oak, the leaf symptoms are variable. Red oaks die rapidly after infection occurs. To date, oak wilt covers about one-third of the area where Minnesota oaks grow. Live oaks were once prized for their naturally curved limbs and trunk, used by shipbuilders in the 18th Century to fashion the ribs and planking of tall sailing ships, such as "Old Ironsides." Today oak wilt is widespread in the southern half of Minnesota and continues to expand its range northward. Vast areas of the Texas Hill Country have been devastated by the fungus that causes the disease called oak wilt. Advanced training is required to accurately diagnose and properly treat the disease. Look for odd or discolored foliage. Oak wilt is generally identified in Live oaks by patterns of tree mortality, and the presence of foliar symptoms (veinal necrosis). Live Oaks typically die within six months of infection with some individuals not dying for years. Oak wilt was first discovered in Minnesota around 1950. Foliar symptoms in Red oaks are less distinct, and oak wilt is generally identified by the “flashing” of autumn colors during summer months and/or the presence of fungal mats. One thing you can do to help prevent anthracnose from spreading or returning to your tree is to keep the fallen leaves raked up all the time. Oak wilt is a major disease problem on live oaks, Shumard oaks, Spanish oaks, water oaks, black jack oaks and other members of the red oak family. Therefore, it is very important that you know for certain what you are dealing with. Members of the white oak group die very slowly after infection occurs and can carry the fungus in the vascular system without showing any symptoms. Symptoms show up on red oaks in early May as a bronzing of the leaves. Other oak species, including White Oak, are affected to a lesser extent. DISTRIBUTION OF OAK WILT DISEASE. Oak species that are particularly susceptible to quick death from oak wilt include: Red Oak, Black Oak, Pin Oak, Burr Oak, Live Oak. Oak Wilt is a disease caused by the fungus Bretiziella fagacearum that is specific to oaks (Quercus spp.). The veins of the leaf turn yellow or brown while the rest of the leaf is green. This is an important disease of all oaks. Red Oaks are particularly susceptible to oak wilt. Examine freshly-fallen leaves to get a closer look. Oak wilt, which is a much more serious tree disease, appears very similar to anthracnose. These hardwoods offer us plenty of shade and are also favored for their grand appearance and the beautiful backdrop of color they provide during the fall months. Oak Wilt most frequently spreads from tree-to-tree by root-to-root contact. 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