Description: Recently detected disease contributing to decline and mortality of beech as of November 2018, BLD has not been detected in Michigan, however, the disease has been confirmed in southwestern New York, northwestern Pennsylvania, Ohio, and along the north shore of Lake Erie in Ontario.
Identification: The disease is confirmed based on the symptoms (dark stripes or banding between leaf veins). Beech leaf curling aphids damage and Eryneum patch may look very similar. As of November 2018, no causal agent has been confirmed. A nematode (microscopic worm) in the genus Litylenchus may be involved.
Habitat: American beech (Fagus grandifolia), European beech (Fagus sylvatica) and Asian beech (Fagus orientalis).
Reproduction: More research is needed.
Impact and Damage: Symptoms of the disease include dark striping or banding between the leaf veins which is noticeable from below. It can also cause reduced leaf size as well as leaf thickening and/or puckering. As the disease progresses, heavily shriveled, discolored, deformed leaves cluster near the branch tips. Eventually, leaf and bud production is reduced. Buds that are produced are small and weakly attached. Observations in Ohio suggest sapling-sized trees may be killed within 2-5 years.
Credits: The information provided in this factsheet was gathered from the Ohio DNR Forest Health Pest Alert, The Ohio State University: Buckeye Yard & Garden onLine and the United States Department of Agriculture.
Individual species images that appear with a number in a black box are courtesy of the Bugwood.org network (http://www.invasive.org). Individual photo author credits may not be included due to the small display size of the images and subsequent difficulty of reading the provided text. All other images appear courtesy of Google (http://images.google.com).
We still do not know the cause of BLD, but researchers are actively investigating this disease.
BLD was initially detected in NE OH in Ohio in 2012 and has now been reported in PA, NY and along the north shore of lake Erie in Ontario. Because of this pattern of distribution, BLD may first appear in SE Michigan.
There are some other less serious beech problems that can be confused with BLD. More information on these common problems can be found at https://bygl.osu.edu/node/885
Report any suspect trees you observe by emailing DNR-FRD-Forest-Health@michigan.gov or by phone at 517-284-5895. Clear, closeup photos of the symptoms and the entire tree are helpful.