Beech Leaf Disease
2022 Update
Beech leaf disease symptoms and defoliation are widespread throughout Westchester and Suffolk counties. In 2022, BLD has been discovered in fourteen new counties including Sullivan, Chenango, Oswego, Steuben, Chemung, Schuyler, Yates, Wayne, Kings, Monroe, Tioga, Herkimer, Ontario, Richmond, and Madison. It was recently discovered in the Adirondacks for the first time, on the southwestern edge of the park. DEC encourages the reporting of new locations through NYiMapInvasives. If you have questions about potential tree pests and pathogens, email photos and a detailed description to foresthealth@dec.ny.gov.
Beech leaves exhibiting the striping
associated with beech leaf disease
Beech leaf disease (BLD) affects and kills both native and ornamental beech tree species. It is associated with a nematode, Litylenchus crenatae mccannii. This disease has only been discovered in recent years and much about it, including the full cause and how it spreads, is still unknown. Because of this, DEC is collecting information on symptomatic beech across New York State in the hopes of learning more about the disease.
On this page:
Threat to Beech
Leaf symptoms caused by beech leaf disease
Beech leaf disease can kill beech trees of all ages in 2 to 7 years, though younger trees appear to die more quickly.
In New York State where our predominant forest type is beech/birch/maple, beech is one of the most common forest species. Beech is particularly valued in the forest for hosting nesting sites and providing nuts for birds, black bears, and other wildlife.
Disease Symptoms
Symptoms of this disease are seen in the leaves and include striping, curling, and/or leathery texture. These symptoms may be visible from leaf out in May until leaves fall off in October and are most easily noticed by looking up into the forest canopy. In early infestations, only a few leaves may be affected. Eventually, affected leaves wither, dry, and yellow.
Reduced leaf and bud production may also occur. Leaf loss has been recorded only in heavily affected trees, but would be noticeable in summer months. A single tree can contain both heavily infected and unaffected branches.
Known Locations in New York and Neighboring States
As of September 2022, beech leaf disease has been found in:
- Western NY: Allegany, Cattaraugus, Chautauqua, Chemung, Erie, Genesee, Livingston, Monroe, Niagara, Ontario, Orleans, Schyler, Steuben, Wayne, Wyoming, and Yates counties.
- Central NY: Cayuga, Chenango, Cortland, Madison, Oswego, Tioga, and Tompkins counties.
- Herkimer county is Northern NY.
- Bronx, Dutchess, Kings,Nassau, Orange, Putnam, Queens, Richmond, Rockland, Suffolk, Sullivan, and Westchester counties in southeastern New York.
New York State counties with beech leaf disease
as of September 2022
We suspect there are infestations elsewhere in the state that we have not yet found, and tracking locations of this disease will help us learn more about its biology.
The disease was first discovered in Ohio in 2012. Neighboring infections currently exist in Ohio, Pennsylvania, New Jersey, Connecticut, Maine, Massachusetts, Rhode Island, and Ontario, Canada.
Current Control Efforts in New York State
DEC's Forest Health team is surveying trees across the state to:
- identify infested stands
- monitor the disease severity and progression
DEC has partnered with other affected states to conduct research and share findings on beech leaf disease.
Currently, there is no known way to control or manage this disease.
How to Report
The backlighting seen when looking up into the forest canopy can
help you spot the leaf striping associated with beech leaf disease.
Because so much about this disease is unknown, finding new infestations can help us learn more about how BLD spreads. Determining and understanding this information is the first step toward developing management techniques. Reports in counties where BLD has been newly found and in counties where it has not been found are especially needed.
After reviewing the identification materials on this website, if you think you have seen signs of beech leaf disease:
- Take photos of symptoms, as well as the tree's leaves, bark, and the entire tree if possible. Photos of leaves held up to the light, or taken through the canopy, make it easier to identify BLD symptoms.
- Submit a report through iMapInvasives (leaves DEC website). Beech leaf diseaes is listed as the nematode Litylenchus crenatae maccannii.
If you have questions about your trees, email photos and location information to foresthealth@dec.ny.gov. Or you may the Forest Health Diagnostic Lab via phone at 1-866-640-0652.
View DEC's BLD flyer about disease symptoms and how to report (PDF).
What You Can Do to Help Stop its Spread
Please follow the New York State Firewood Regulation to help prevent the spread of all pests and diseases that threatened our forests. Do not move untreated firewood more than 50 miles from its source or origin. If BLD symptoms are observed in an area, avoid moving firewood from that location.
Look-alikes and Other Beech Phenomena
Review the table below for other issues you may see on beech trees. It is possible for a beech tree to exhibit symptoms of both beech leaf disease and any of these other impacts simultaneously.
DEC is interested in reports of leaf striping or curling associated with BLD on any beech tree, but we do not manage the other issues listed in the table.
If you have questions about any of the diseases or phenomena listed in the table, please click "learn more" in the "About" column.
| Name | Signs and Symptoms | About |
|---|---|---|
| Beech bark disease (BBD) |
Symptoms: The symptoms of this disease are concentrated on the bark. A white, fuzzy coating on the tree's trunk and branches is a sign of the scale insect.
|
Beech bark disease is the result of the combined effects of a non-native scale insect and a canker fungi. The insect pierces and sucks at the tree, allowing the fungus to enter and cause harm internally. This disease is common across New York State and is not managed by DEC. Most trees die within 10 years of infestation by the insect and fungi. |
| Erineum patch |
Symptoms: Yellowish patches appear on the upper side of the leaf. The patches are light green in spring, then fade to orange and eventually brown.
|
Erineum patch is caused by eriophyid mites and is not typically viewed as a problem. The patches rarely cover enough of the leaf to affect the overall health of the tree. |
| Powdery mildew |
Symptoms: Leaves and stems appear to be covered in a white, powdery substance that resembles powdered sugar.
|
Powdery mildew is caused by native fungi and affects a variety of shrubs and trees. This is a cosmetic disease that does not kill the tree but could cause defoliation if not addressed. |
| Anthracnose |
Symptoms: Small brown or black spots on leaves that eventually cause dead areas. New leaves may curl.
|
Anthracnose affects a variety of tree species and is caused by a group of fungi. In beech, the fungi infect the leaves and stems and can cause dieback or some defoliation. The disease thrives in years where there are cool, wet conditions during bud break. |
| Beech blight aphid |
Signs: These native insects have a fluffy, white outer coating. Also known as "boogie woogie aphids", the insects will shake or "dance" when the branch is disturbed in order to ward off potential predators.
|
This insect is native and feeds on beech without causing much harm. |
| Beech leaf rolling aphid |
Signs: Leaves may curl and appear yellow/faded between the veins.
|
These injuries are caused by aphids feeding on the leaves. This insect is native and feeds on beech without causing much harm. |
| Marcescense |
Signs: Beech retain their dead leaves through the winter.
|
This is a totally normal, common, and harmless feature of beech. |
Additional Resources
- BLD information from Forest Invasives Canada (leaves DEC website)
- BLD fact sheet from the Connecticut Agricultural Experiment Station (PDF) (shared with permission from source)