​Signs of Emerald Ash Borer Infestation

Emerald Ash Borer spends most of its life under the bark of an ash tree. This makes it hard to spot. Instead, look for these signs of infestation in your trees:

​Woodpecker damage The first sign you might see is woodpecker activity on your ash trees. Woodpeckers will strip off pieces of bark, leaving lighter exposed layers.
​Crown thinning You will begin to see thinning of the leaves in the canopy, usually starting at the tops and sides.
“D” shaped exit holes “D” shaped exit holes on your tree definitively indicate Emerald Ash Borer.
​“S” shaped galleries Underneath the bark, Emerald Ash Borer will make “S” shaped galleries as it tunnels through the tree.

​Bark splitting Vertical cracks in the bark might appear along the trunk or branches	​	​Epicormic sprouts Sprouts may form around the tree base or branches, indicating that your tree is stressed.	​

 

Don’t mistake these look-alikes for Emerald Ash Borer

Native Borers

 

We have several species of native ash borers. The lilac/ash borer (left) and the banded ash borer (right) have larger, rounder exit holes than Emerald Ash Borer.

Bronze Birch Borer	Sweat Bee	Common green bottle fly​
Green June beetle	Japanese beetle	Six spotted tiger beetle

Photography Acknowledgements:

• Eggs: David Cappaert. Bugwood.org
• Larvae: David Cappaert, Bugwood.org
• Adult 1: Pennsylvania Department of Conservation and Natural Resources- Forestry, Bugwood.org
• Adult 2: David Cappaert, Bugwood.org
• Woodpecker damage: Kenneth R. Law, USDA APHIS PPQ, Bugwood.org
• Crown thinning: Eric R. Day, Virginia Polytechnic Institute and State University, Bugwood.org
• Exit hole: Daniel Herms, The Ohio State University, Bugwood.org
• Galleries: William M. Ciesla, Forest Health Management International, Bugwood.org
• Bark Splitting: Michigan Department of Agriculture, Bugwood.org
• Sprouts: Pennsylvania Department of Conservation and Natural Resource, Bugwood.org
• Lilac/ash borer: Steven Katovich, USDA Forest Service, Bugwood.org
• Banded ash borer: Whitney Cranshaw, Colorado State University, Bugwood.org
• Bronze birch borer: Whitney Cranshaw, Colorado State University, Bugwood.org
• Sweat bee: David Cappaert, Bugwood.org
• Common green bottle fly: Joseph Berger, Bugwood.org
• Green June beetle: Kansas Department of Agriculture, Bugwood.org
• Japanese beetle: Steven Katovich, USDA Forest Service, Bugwood.org
• Six spotted tiger beetle: David Cappaert, Bugwood.org