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Emerald Ash Borer in Wisconsin

Emerald Ash Borer (EAB)


2019 will likely be the last year to protect your favorite ash tree from the Emerald Ash Borer. This heightens the importance of having your ash trees professionally inspected right away for any chance of survival. Remember, if you have been receiving professional treatments for EAB, these treatments need to continue to keep your ash tree thriving.

If you are unsure if your ash tree has been affected, Wachtel Tree Science will come out for a free inspection to determine a plan of action. Just give us a call!

Emerald Ash Borer (EAB) continues to destroy ash trees all across Wisconsin. EAB came to the United States in 2002, ventured their way to Wisconsin in 2008, and has now affected 33 states. Wachtel Tree Science has been providing Emerald Ash Borer Treatments ever since, bringing local ash trees back to life. Although adult beetles cause little damage, the larvae feed on the inner bark of ash trees and prevent the tree from transporting water and nutrients.


  • D-Shaped exit holes in the bark (about 1/8 inch in diameter)
  • S-shaped “tunnels” underneath bark
  • Ash tree with a thin look to the crown or leaves on the ground in summer
  • Notches on the side of the leaves
  • Metallic Green colored beetles (about ½ inch long)
  • Yellow leaves

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What should I replace my Ash tree with?

If your ash tree was removed due to EAB, there are a number of trees we recommend planting in its place. Our professional arborists will recommend different options based on your desires for your property.

Do I need to continue EAB treatments for my ash tree?

Yes! To keep your ash tree from being re-infected from EAB, you must continue your treatments annually.

What damage does Emerald Ash Borer cause?

In the short-term they cause damage to tree bark and leaves of the tree. If gone untreated, the tree will die and need to be professionally removed to prevent the spread of EAB in neighboring ash trees.

When should I be on the lookout for EAB?

Late June to Mid-August is when adults lay eggs in the ash bark, where the eggs then hatch. They will then make their way through the tree between August and October, live in the tree over the winter, and exit the tree as adults leaving the D-Shaped exit holes.

Why is the Emerald Ash Borer a problem?

Ash trees make up roughly 15% of our tree population and are the 2nd most common tree in urban areas. Ash trees provide beauty and shade across the state. Wisconsin would seem empty without them. EAB is costing billions of dollars nationwide for trees that have gone untreated.

What is the best treatment for Emerald Ash Borer?

Ash trees need to be professionally treated every other year using science based methods. Although there are DIY solutions available on the market, only the injection of a restricted pesticide by a licensed Arborist will prevent EAB from killing an Ash tree.

What trees are affected by Emerald Ash Borer?

In North America, ash trees are the only trees that are attacked by Emerald Ash Borer.

Should I be concerned if I have a healthy tree next to a tree with EAB?

Yes! EAB adults can fly up to ½ mile from where they emerge from the tree. Is important to keep a close eye on all ash trees in your area. NOTE: Moving ash tree firewood is an easy way to spread EAB and should be avoided to prevent the spread of EAB.

How do I prevent EAB?

The best way to keep your ash trees safe from EAB is to an arborist come and inspect your trees annually. This way the EAB infestation can be caught early and prevent your tree from serious damage.

Emerald Ash Borer Resource Center