Is My Ash Tree Infected?

Picture of an Emerald Ash Borer on a leaf

Year 1

Detecting an Emerald Ash Borer (EAB) infestation can be difficult. In the initial stages of the infestation, the ash tree does not show any outward symptoms. As the infestation grows, the tree’s health will decline rather quickly and the tree will die if left untreated. The EAB has already killed over 50 million ash trees in the U.S. and Canada.

Once the infestation progresses, the symptoms will start to appear. This begins with the yellowing and dropping of leaves from the upper canopy of the tree. As the infestation grows more severe, some of the branches will completely die. The tree will usually sprout new branches from the lower trunk to replace the dead branches in the upper canopy.

An Emerald Ash Tree Borer emerges from the trunk
Emerging from the trunk of an ash tree, an emerald ash borer is infected with Beauveria bassiana, an insect-pathogenic fungus that may prove to be a valuable biocontrol for this pest.

Year 2

After the first year small, D-shaped holes will appear in the tree as the larvae mature and tunnel their way out of the tree to begin the next egg-laying cycle. Infested trees may also develop splits in their bark. Woodpecker holes are also common in infested trees since the woodpeckers may search for EAB larvae to eat.

An emerald ash borer's trail underneath the bark of a trunk
Adult emerald ash borers emerge from an infested ash tree (Fraxinus pennsylvanica).

As soon as you detect any of these symptoms in your ash trees or any ash trees near you, call 4 Seasons Arbor Service. Our certified arborist will do a full evaluation and help you to determine the best course of action for your trees. Generally, if an infected tree has lost less than 40% of its canopy, it can still be saved through treatment. If trees near your property are showing signs of infestation, it is probably wise to treat any trees on your property even if they are not currently showing any signs of infestation. Mature trees also add to the value of your property and provide many other benefits. If it is possible, treat your tree; don’t remove it!

4 Seasons Arbor Service dedicates itself to saving as many ash trees as possible from EAB. If you have questions or concerns about your trees, call us today at (708) 371-5439.

For more information, visit this website. It contains a helpful PDF with more pictures and information.