How To Identify Emerald Ash Borer Damage

Signs of Emerald Ash Borer Damage Finding Ohio
Signs of Emerald Ash Borer Damage Finding Ohio from


The emerald ash borer (EAB) is an invasive beetle that has caused significant damage to ash trees across the United States. First discovered in 2002, this destructive insect has become a major concern for homeowners, arborists, and forestry professionals. Identifying the signs of EAB infestation is crucial for early detection and management. In this article, we will discuss how to identify emerald ash borer damage and take necessary action.

What is Emerald Ash Borer?

The emerald ash borer is a small, metallic green beetle native to Asia. It primarily attacks ash trees, feeding on the inner bark and disrupting the tree’s ability to transport water and nutrients. EAB larvae create winding galleries underneath the bark, causing extensive damage that can ultimately lead to the death of the tree.

Signs of Infestation

1. D-shaped Exit Holes

One of the most recognizable signs of emerald ash borer infestation is the presence of D-shaped exit holes on the trunk and branches of ash trees. These small, distinct holes are created when adult beetles emerge from the tree after completing their lifecycle.

2. S-shaped Serpentine Galleries

EAB larvae create distinct serpentine galleries underneath the bark, which can be seen by peeling back the outer layer. These galleries disrupt the flow of nutrients and water, leading to dieback in the canopy and overall decline of the tree’s health.

3. Bark Splits and Woodpecker Activity

As EAB larvae tunnel through the inner bark, it causes the bark to split or crack. This can often be observed on the trunk and major branches of infested ash trees. Woodpecker activity is another telltale sign of EAB infestation, as they feed on the larvae present beneath the bark.

4. Thinning Canopy and Epicormic Shoots

Infested ash trees may exhibit a thinning canopy, with branches and leaves dying off. In an attempt to survive, the tree may produce epicormic shoots or sprouts along the trunk or lower branches. These shoots are a response to stress and can be an indicator of EAB infestation.

What to Do if You Suspect EAB Infestation?

If you suspect EAB infestation in your ash trees, it is essential to take prompt action. Contact a certified arborist or forestry professional who can assess the situation and provide appropriate treatment options. Early detection and management are crucial in preventing the spread of EAB and preserving ash tree populations.

Preventing the Spread of EAB

Preventing the spread of emerald ash borer is of utmost importance to protect unaffected ash trees. Avoid transporting firewood, logs, or other ash wood products from infested areas to non-infested regions. Be cautious when purchasing ash trees from nurseries, ensuring they are certified as EAB-free.


Identifying emerald ash borer damage is vital for early detection and management of this invasive beetle. By recognizing the signs of infestation, you can take appropriate action to protect ash trees and prevent the spread of EAB. If you suspect an infestation, seek professional assistance to ensure the best possible outcome for your trees and surrounding environment.