Oak trees supply 1/3 of the hardwood for saw timber, according to ForestPests.org. Wood from oak trees is used in making fine furniture, flooring and other items. Industries that use oak timber suffer the most from oak diseases and pests. It's much easier to prevent problems than try to cure them. In addition to practicing good tree hygiene, avoid injuring the tree through cuts and broken limbs to reduce pest attacks and fungal infections.
Oak tatters is a somewhat new disease that causes oak leaves to look tattered or lacy. This disease has been found throughout Midwestern states including Michigan, Minnesota, Iowa, Wisconsin, Illinois, Ohio, Indiana and Missouri. Damage is first noticeable when a leaf emerges around middle-to-late May. Within two to three weeks, a tree that's severely affected will produce new flushes of leaves that may or may not have these tatters. Affected leaves are lighter in color and smaller than normal leaves. When seen from a distance, infected trees appear to lack leaves. Although healthy trees are able to survive oat tatters, trees with repeated damage suffer decline or can even die.
Oak wilt is an aggressive fungal infection that affects various oak species; red oaks are the most susceptible. Other oaks that are vulnerable include Texas live oaks and white oaks. This serious disease is caused by the fungus Ceratocystic fagacearum and is mostly found in the eastern United States. It blocks a tree's vascular system, which prevents the flow of water and nutrients. An initial symptom of oak wilt is leaf damage and a tree losing its green color and then turning brown or yellow. A tree literally wilts and dies once it is infected. This disease moves quickly and can kill a tree within one month. There's no known cure for oak wilt, but the best method of controlling the disease is isolating and then destroying an affected tree.
Trees affected from flat-headed oak borers may fail to show signs of an oak borer infestation until the leaves turn brown and branches die back with the crown of the tree thinning. These infestations usually occur in a tree's upper crown and then travel downward. Some trees exhibit gummy or wet bark. Because there's a lack of external symptoms, it helps to peel back a small portion of bark to confirm an infestation. Trees lightly infected can be sprayed with bark sprays to avoid more infection. Larvae should also have a systemic applied, which is a pesticide that is absorbed into plants, making their roots, parts, leaves and stems poisonous to an invading organism. Stressed trees, improper planting or compacted soil are contributing factors.