The Michigan departments of Natural Resources and Agriculture and Rural Development recently confirmed the presence of invasive beech leaf disease in a small, private woodlot in southern St. Clair County, located in southeast Michigan.
Beech leaf disease, not previously known to be in Michigan, is associated with the microscopic worm Litylenchus crenatae, a nematode that enters and spends the winter in leaf buds, causing damage to leaf tissue on American, European and Asian beech species. Trees weakened by leaf damage become susceptible to other diseases and can die within six to 10 years after initial symptoms.
Michigan is home to approximately 37 million American beech trees. Recognizable by their smooth bark, they are an important component to forests, providing food and shelter for wildlife.
With no known treatment available for beech leaf disease, its potential spread through the region could have a devastating effect on beech trees, already under attack from beech bark disease.
Landowners reported the suspected beech leaf disease outbreak in St. Clair County through the Midwest Invasive Species Information Network after noticing stunted, odd-shaped leaves on young beech trees in a wooded area on their property. DNR forest health staff collected samples for preliminary testing by the Michigan State University Forest Pathology Laboratory. Results were confirmed by the U.S. Department of Agriculture’s Animal and Plant Health Inspection Service.
“Though beech leaf disease was detected this spring, the condition of the leaves and number of trees affected at this location suggest the disease has been there for more than a year,” said Simeon Wright, DNR forest health specialist. “Because symptoms are slow to emerge, it is difficult to detect the disease before it is established.”
Beech leaf disease was first detected in Ohio in 2012. Subsequent discoveries in other states and Ontario initiated widespread, annual surveys across the
