11 Feb Common Michigan Tree Diseases
Just like people and animals, trees contract diseases detrimental to their health. Some so serious that they lead to death and the need for removal. Unfortunately, removing the dead or dying tree often fails to remove the problem — as these diseases spread from one tree to the next at a rapid rate. The most common parasitic and fungal diseases attacking Michigan trees included beech bark and oak wilt.
Beech bark disease presents as a devastating, two-part disease that destroys even the strongest of trees. It begins with an infestation of incredibly small soft-bodied insects called beech scales which only measure about one millimeter in length. These insects colonize rough sections of bark to easily feed on the tree’s sap with tube-like stylet. The infestation of the beech scale — evident by a white waxy appearance from the insect’s secretions — eventually overwhelms a tree. Over time, the beech scale facilitates the introduction of Necteria fungus. The fungal infection then proceeds to create tarry spots on the tree that ooze a brownish fluid. In some cases, the tree saves itself by walling off the infected area, but high numbers of beech scale gives the tree little chance of survival.
Actually categorized as a fungal infection, oak wilt disease often affects an entire group of oak trees before the problem presents itself visually to the untrained eye. After the initial infection, the fungus spreads throughout the oak’s entirety. Symptoms usually appearing as leaf browning beginning at the tips and working its way to the base and fungal mats called pressure pads developing under the bark. This infection quickly spreads to surrounding oaks within a year. Its transmission becomes accelerated by indigenous picnic beetles or by grafted tree roots.
To reduce the chances of these diseases destroying our trees, we must be watchful of symptoms which usually present as discoloration to leaves and bark. In doing so, we ensure the continued health and long life of our Michigan trees.