darker green stripes on beech leaves

Beech leaf disease symptom
Photo: Jim Chatfield, OSU Extension

Updated: August 16, 2022

Key points

  • Beech leaf disease (BLD) is caused by a foliar-feeding nematode (non-segmented, microscopic worm), Litylenchus crenatae. The connection between the nematode and mode of infection is not fully understood at this time, but research is ongoing.
  • American and European beeches are susceptible to the disease. American beech (Fagus grandifolia), a tree native to eastern North America, is a beautiful and important forest tree known for its smooth bark. Beeches are also planted as ornamental trees in the landscape. 
  • (BLD) was first detected in the Cleveland, Ohio area in 2012. Since then, it has been detected in other Ohio counties, Connecticut, Massachusetts, New Jersey, New York, Pennsylvania, Rhode Island, West Virginia, and the Canadian Province of Ontario. The disease was also confirmed in Prince William County, Virginia in the summer of 2021.
the smooth grey bark of a beech tree
The smooth, iconic, grey bark of a mature beech tree
Photo: C. Carignan, HGIC

Symptoms

  • Dark stripes or bands between lateral veins of leaves are a distinct, early symptom of an infection. They are visible immediately upon bud break in the spring. 
  • The bands are best seen by looking at the leaves from below and allowing sunlight to pass through the leaf tissue.
  • Thickening and leaf distortion can also be observed.
  • Infected leaves may be unevenly distributed in the lower canopy. 
  • Thinning of the leaf canopy happens over time due to early leaf drop and aborted leaf bud development. This stresses and weakens trees causing them to die.

 What to do if you find beech leaf disease

Contact us through Ask Extension. Attach digital photos of your observation along with your question.

Resources and additional resources

USDA Forest Service Pest Alert | (PDF) Beech Leaf Diseases

Virginia Department of Forestry | Beech Leaf Disease Confirmed in Virginia

The Maryland Invasive Species Council | Invader of the Month -  New Leaf Disease is a Beech

 

Compiled by Debra Ricigliano, HGIC. Reviewed by Dr. Dave Clement, Extension Specialist, Plant Pathology