Beech Leaf Disease

Scientists from the Connecticut Agricultural Experiment Station (CAES) are reporting that Beech Leaf Disease (BLD) has increased dramatically in both severity and distribution in 2022 compared to 2021. First detected in lower Fairfield County in 2019, BLD is now widespread on American beech (Fagus grandifolia) throughout all eight Connecticut counties, with symptoms most severe in Fairfield, New Haven, Middlesex and New London Counties. Given that BLD is now widely established throughout Connecticut, reports of BLD to CAES and DEEP are no longer requested.

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. 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.

DNR and MDARD encourage monitoring for any signs of the disease. If you suspect you have found a symptomatic tree, take one or more photos of the infested tree, including close-ups of affected leaves; note the location, date and time; and report it in one of the following ways:

• DNR Forest Health Division: Email DNR-FRD-Forest-Health@Michigan.gov or call 517-284-5895.
• Use the Midwest Invasive Species Information Network (MISIN) online reporting tool.
• Download the MISIN smartphone app and report from your phone.

The New York State Department of Environmental Conservation (DEC) today announced that Beech Leaf Disease (BLD), which affects all species of beech trees, was identified in 35 counties in New York State to date. DEC began tracking BLD in 2018 after it was confirmed in Chautauqua County. Fourteen of the counties with BLD were confirmed in 2022, and more are likely to be identified. At this time there are no specific recommendations for managing trees that are infected with BLD, however, DEC encourages the public to report potential BLD infections using iMapInvasives to help track the disease while research is ongoing. Learn more about Beech Leaf Disease. For questions about potential tree pests or pathogens, email photos and a description to foresthealth@dec.ny.gov.

Beech leaf disease has now been confirmed in Prince William County – the first detection in Virginia. The disease affects American beech (Fagus grandifolia) trees and is associated with a foliar nematode. Symptoms include dark stripes between leaf veins, thickening and curling of leaves, and canopy thinning. Contact VDOF's forest health program if you see these symptoms. For more information, view this Beech Leaf Disease Pest Alert (Jan 2021) [PDF, 312 KB] publication.

See also: More Information Relating to the First Report of Beech Leaf Disease in Virginia [Aug 2021) [PDF, 951 KB]

A chance discovery in an Ohio woodland has turned into a multi-disciplinary, multi-agency, and multi-national effort to piece together a puzzle and understand a scourge that is killing trees by the thousands in northern states east of the Great Plains. The leaves of young beech trees are failing somehow. Scientists have figured out what causes the malady; it’s the 'how' that has them scratching their heads. Beech trees are one of the most common trees in America's northern and northeastern forests. Their nut crop feeds birds and other animals, and its wood is prized for bentwood furniture. The symptoms of beech leaf disease were plain to see – sunken dark spots on the leaves, which eventually died – but opinions differed on the cause. Was it bacterial, fungal, or viral? Then, a plant pathologist working for the State of Ohio noticed wiggly things in the leaf lesions. They turned out to be nematodes, microscopic worms that live in the soil, that had somehow managed to make it to the tree canopy 40-50 feet above ground. Nematode samples were sent to Beltsville, MD, for analysis and identification at the Agricultural Research Service (ARS) Mycology and Nematology Genetic Diversity and Biology Laboratory in Beltsville, MD. The nematode, Litylenchus crenatae, turned out to be native to Japan – the first population of L. crenatae found in the Western Hemisphere. The curious thing is that it's not a tree-killer in Japan.