Emerald Ash Borer

Agrilus planipennis

Quick Facts

The emerald ash borer is a green, shiny beetle that lives on ash trees in certain parts of Maryland, Virginia and Pennsylvania. It is an invasive species.


The emerald ash borer has a metallic, bright green body, a flat back and a rounded belly. It grows to one-half inch in length.


Adults eat ash tree leaves. Young feed on ash tree tissue just under the bark, forming S-shaped lines in the tree.


Woodpeckers prey on emerald ash borer larvae.

Reproduction and Life Cycle

Between May and June, adults emerge from ash trees, leaving D-shaped exit holes in the trees. Females lay their eggs on ash tree bark between mid-May and mid-August. After the eggs hatch, larvae burrow under the bark. They feed on the tissue that carries food and water up and down the tree, which starves the tree to death. Larvae remain in the ash tree through the winter.

Did You Know?

  • The emerald ash borer was introduced to the Chesapeake Bay watershed in 2003 when a Michigan nursery shipped ash trees to Maryland.
  • It is estimated that emerald ash borders have killed more than 20 million ash trees in Ohio, Indiana and Michigan.
  • To help stop the spread of the emerald ash borer, don’t move firewood from one location to another. Emerald ash borer larvae can live in firewood.
  • If you find or suspect an emerald ash borer in Maryland, call the Department of Agriculture at (410) 841-5920. In Pennsylvania, call (866) 253-7189. In Fairfax County, Virginia, call (703) 324-5304.

Sources and Additional Information

Quick Facts