Which States Have Emerald Ash Borers?

Written by Lex Basu
Updated: October 5, 2022
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Key Points

  • Emerald Ash Borers are a species of invasive beetle that was introduced to North America through shipping of woods from other regions.
  • They are native to Asia and inhabit parts of Russia, Japan, Korea, China, and Mongolia.
  • They can destroy an entire population of Ash trees within very short span of time.

Emerald ash borers or EAB are a massive problem in North America. Initially they were native to Asia, including territories such as parts of Russia, Mongolia, Japan, parts of China, Korea, and they were believed to have intruded North America through shipments of logs and wood from those parts in the world. These species of beetle are very invasive in North America and harmful to the population of Ash trees.

These little bugs can kill off an entire population of ash trees without taking too much time. If you live in one of the states affected by these pests, you must take action to protect your trees. Here is some helpful information about which states have these pesky critters and what you can do to protect your trees.

What Are Emerald Ash Borers?

These insects are a type of wood-boring beetle native to different parts of Asia. The adult beetle is dark green in color, measuring 1/2 inch long and 1/8 inch wide. It preys on ash trees. In the U.S., they were first discovered in southeastern Michigan way back in 2002.

Although the origin of these bugs in the U.S. is unclear, experts say it arrived through wood packing materials from Asia. Since then, these invasive species have spread across North America.

These insects don’t just kill ash trees — they destroy them. The larvae burrow into the tree’s bark and consume the layers of wood, cutting off the flow of crucial nutrients. This eventually leads to the tree perishing.

These beetles are a serious threat to North American forests, and there is no known way to stop their spread. However, early detection is key to preventing further damage, and efforts are underway to control their spread.

emerald ash borer

Emerald Ash Borers are native to Asia but have been increasingly migrating to North America.

©Herman Wong HM/Shutterstock.com

Which States Have EAB?

EAB are in 35 states so far. These are:

  • Colorado
  • Alabama
  • Kansas
  • New Hampshire
  • Ohio
  • Iowa
  • Missouri
  • New Jersey
  • Louisiana
  • Texas
  • Kentucky
  • South Dakota
  • Maine
  • Virginia
  • Minnesota
  • West Virginia
  • New York
  • Indiana
  • Rhode Island
  • North Carolina
  • Tennessee
  • Arkansas
  • Nebraska
  • Vermont
  • Michigan
  • Wisconsin
  • Oklahoma
  • Georgia
  • South Carolina
  • Maryland
  • Illinois
  • Connecticut
  • Pennsylvania
  • Delaware
  • Massachusetts

If you live in one of these states, it is crucial to look for these creatures. These pests can kill even healthy trees in just a few years. As such, it is critical to take action to protect your trees.

These Bugs Affect Which Trees?

These insects have wreaked havoc on Ash trees across North America since its first detection in 2002. It feeds on the inner bark of Ash trees, causing the tree to starve and eventually die. Although all species of the Ash tree are susceptible to this infestation, the most affected one is the White Ash.

The White Ash is a large deciduous tree native to eastern North America. It is frequently used as a shade tree or landscaping due to its stately appearance and resistance to disease. However, this resistance does not extend to this beetle. The White Ash has been particularly hard hit by the insect’s onslaught.

While the borers kill a vast majority of these trees outright, a small number manage to survive. These “lingering ash” trees are either white or green Ash, and they tend to be younger and healthier than the trees that succumb to the infestation.

While they are not immune to the borers, lingering ash trees have a greater capacity to resist infestation and recover from damage. As a result, they provide an essential source of genetic material for efforts to breed resistance into future generations of ash trees. While the fight against this pest is far from over, these surviving trees offer a glimmer of hope for the future of this iconic species.

white ash tree

The White Ash tree of North America has been hit particularly hard by the Emerald Ash Borers.


Signs of an EAB Infestation

Several signs indicate whether a tree has borers. These include:

Crown Dieback

Crown dieback is one sign of an infestation in an ash tree. This occurs when the upper branches start to die off. The leaves of the affected branches will turn yellow or brown and then fall off. Ultimately, the entire crown of the tree will die. If you notice crown dieback in an ash tree, you must have an arborist assess the tree. They can determine if the tree has the borers. If so, they have the expertise to recommend a course of treatment.

D-shaped Holes in the Bark

One of the most distinctive signs of an infestation is D-shaped holes in the bark of an ash tree. These holes occur when the adult beetles emerge from the bark after completing their life cycle.

Epicormic Sprouting

Epicormic sprouting is one of the most visible signs of this beetle infestation. This phenomenon occurs when the borers damage the tree’s growth buds. This causes the tree to produce new shoots from dormant buds lower on the trunk and branches. These new shoots, known as epicormic sprouts, are often weak and vulnerable to breakage.

Splitting or Cracks in the Bark

Another sign of an infestation is bark splits. These splits occur when the larvae of this insect tunnel through the bark, causing the outer layers to separate from the inner ones. Bark splits are usually most noticeable on the south or southwest side of the tree, as this is where the larvae tend to congregate.

Woodpecker Flecking

Lastly, another symptom to watch out for is Woodpecker flecking. This is when woodpeckers peck away at the tree bark. In turn, this exposes the creamy white inner wood. The larvae of this pest, which tunnel beneath the bark and feed on the tree’s tissue, attract the woodpeckers.

What Threat Does the Borer Pose?

This bug threatens ash trees all over North America. To date, this critter has:

Killed Hundreds of Millions of Ash Trees Across North America

This beetle attacks all species of ash trees, causing them to slowly die over several years. It has killed millions of ash trees across the U.S. and Canada, including 40 million in Michigan alone.

This nuisance has been particularly devastating because it has no natural predators in North America. As a result, the beetle has been able to spread rapidly and destroy vast tracts of forest. In some areas, this pest has killed so many trees that it has changed the landscape dramatically.

Forced Regulatory Agencies to Impose Quarantines

Regulatory agencies have placed quarantines in areas where this bug is present to prevent the further spread of this destructive pest. These quarantines prohibit the movement of ash trees, logs, or hardwood firewood out of the quarantined area. Violations of the quarantine can result in hefty fines. Although quarantines are not 100% effective, they are an essential tool for slowing the spread of these invasive species.

Caused Hundreds of Millions of Dollars in Damage

The economic impact of this malicious species has been staggering, with various industry stakeholders incurring high costs.

What Can You Do to Help?

The U.S. Department of Agriculture recommends taking the following steps:

1) Get in Touch with the Proper Authorities

To help control the spread of this beetle, the USDA has established a hotline for reporting suspected infestations. If you’ve spotted an infestation, call 1-866-322-4512. You may also contact your local APHIS office. These professionals can confirm whether you have an infestation and, if so, will work with you to develop a management plan.

2) Document the Infestation

If you think you may have found an infestation, it is vital to act immediately. First, record the location where you spotted the bug. This will help authorities track the spread of the infestation. Then, take numerous photos of the insect and the damage it has triggered. The images will confirm the beetle’s identity and assess the damage’s extent.

3) Avoid Transporting Firewood

The most effective way to prevent an infestation is to avoid transporting firewood, as the insects can hitch a ride on logs and end up in new areas. It’s important to never move firewood from your land or transport it past state boundaries. This is because this increases the risk of spreading the borer.

4) Acquire Firewood from Local Sellers

To prevent this bug infestation, it is crucial to buy firewood from homegrown sources and burn it where you buy it. The borer can hitchhike on firewood, so by buying locally, you can be sure that the wood does not come from an infested area. Burning the wood where you buy it also helps prevent the insect’s spread, as it cannot survive in hot temperatures.

5) Find a Suitable Treatment for Your Trees

If you have an ash tree on your property that has a borer infestation, there are several products that you can use to treat it. These products will help to protect your tree and prevent the infestation from spreading. However, it is important to note that not all products are effective against this beetle. As such, you should always consult with a professional before using any treatment product on your trees.


The EAB is a destructive pest that has caused an enormous amount of damage. To date, it is in 35 states and continues to spread. Regulatory agencies have placed quarantines in areas where this bug is present.

However, the most effective way to prevent an infestation is to avoid transporting firewood. You can also help by getting in touch with the proper authorities if you think you’ve spotted an infestation. Taking these steps will help prevent this destructive pest’s further spread.

Next Up…

The photo featured at the top of this post is © Herman Wong HM/Shutterstock.com

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About the Author

Lex is a green-living, tree-hugging, animal-lover, who at one time was the mother to twenty one felines and one doggo. Now she helps pet owners around the globe be the best caretakers for their most trusting companions by sharing her experience and spreading love.

FAQs (Frequently Asked Questions) 

What is the best treatment for Emerald Ash Borer?

The best treatment for Emerald Ash Borer is an injection by a professional pesticide applicator.

Can my trees be saved if they have EAB?

If treatment is done correctly, it can be up to 95% effective.

Can I treat EAB myself?

It depends on the case. If EAB is smaller than 47 inches around the trunk, you might be able to treat it yourself.

Thank you for reading! Have some feedback for us? Contact the AZ Animals editorial team.

  1. Science Daily, Available here: https://www.sciencedaily.com/releases/2019/09/190909170754.htm
  2. WISCONSIN DEPARTMENT OF NATURAL RESOURCES, Available here: https://dnr.wisconsin.gov/topic/foresthealth/emeraldashborer/signs
  3. Arbor Day Foundation, Available here: https://www.arborday.org/trees/health/pests/emerald-ash-borer.cfm
  4. Animal and Plant Health Inspection Service U.S. DEPARTMENT OF AGRICULTURE, Available here: https://www.aphis.usda.gov/aphis/ourfocus/planthealth/plant-pest-and-disease-programs/pests-and-diseases/emerald-ash-borer#:~:text=Today%2C%20EAB%20infestations%20have%20been,New%20Jersey%2C%20New%20York%2C%20North