GRAND RAPIDS, Mich. (WOOD) — The Michigan Department of Natural Resources and the Department of Agriculture and Rural Development confirm a new disease has been found in the state that targets beech trees.
Beech leaf disease was confirmed last week in a St. Clair County, northeast of Detroit. The disease is caused by a nematode that invades the tree through the leaf buds and winters there, causing damage to the leaf tissue. The damage weakens the trees and makes them more susceptible to other diseases, including beech bark disease. The trees usually die within six to 10 years after the first symptoms are spotted.
According to the DNR, the landowners noticed stunted and odd-shaped leaves on some of their beech trees and reached out to the Midwest Invasive Species Information Network. DNR staff collected samples and Michigan State University’s Forest Pathology Lab conducted the preliminary tests. The U.S. Department of Agriculture confirmed the findings.
Simeon Wright, a forest health specialist with the Michigan DNR, said one of the big struggles with fighting Beech leaf disease is that it’s hard to detect before it is well established within the tree.
“Though beech leaf disease was detected this spring, the condition of the leaves and the number of trees affected at the location suggest the disease has been there for more than a year,” Wright said in a release.
Beech leaf disease was first found in Ohio in 2012 and has since been found in nine other states and Ontario, Canada.
The damaged leaves will have dark, thick bands between the leaf’s veins. Eventually, the leaves will start to wither and dry. Trees with a heavy infestation tend to lose their leaves early in the summer.
Michigan is home to an estimated 37 million American beech trees. They have an extremely smooth gray bark and are a key component of forest life, providing food and shelter for wildlife.
Researchers say there is still very little known about beech leaf disease. They know the microscopic nematodes cause the damage but not exactly how they do it.
“We don’t yet know all the ways the disease might be spread, and currently there are no known treatments to protect trees or reduce disease impacts,” Wright said in a release.
On their own, nematodes can’t travel long distances, so it is most likely that the virus spreads by the human movement of beech trees or tree material.
The DNR and MDARD encourage anyone who believes they have found a symptomatic tree to take pictures, including close-ups of the leaves, and to include the date, time and location of the tree. That information can be submitted to the DNR’s Forest Health Division or the Midwest Invasive Species Information Network.