Emerald ash borer (EAB) is a small, bright metallic green beetle that kills ash trees. Originally from eastern Asia, it is a minor pest of ash trees that was introduced to North America during 2002 in an ash wood packing crate sent to Detroit. It has since spread over 33 states. Find out how to identify EAB here.
Nonnative species are organisms introduced with human help outside their natural range of dispersal. These organisms fall broadly into two categories: benign and destructive. Benign organisms do not pose a danger to native ecosystems and may benefit people. For example, tomatoes are not native to North America but they do not spread outside of cultivation and are in many foods we eat. Invasive species cause ecological and economic harm. For example, zebra mussels out compete native animals for food and can clog water filtration systems. For more information, see the National Invasive Species Information Center website.
You should still be concerned about EAB because:
Dead ash trees need to be removed as quickly as possible. When ash trees die, they become extremely brittle and can fall or drop branches at any time. Falling limbs can destroy property and injure or even kill people they strike. Wood collected from dead ash trees should be handled properly to ensure that it does not contribute to the spread of EAB. For more information, see My ash tree is dead…Now what do I do? (pdf).
It is not always clear who is responsible for the maintenance of a tree, particularly if it grows between a road and private property. Laws concerning tree ownership vary from state to state and town to town. If you are uncertain if you are responsible for a tree, it is always best to consult with the local municipal body before treating or cutting a tree. However, do not let uncertainty about tree ownership stop you from making sure that a healthy tree is treated or a dying tree is removed. Waiting even a year can mean the difference between a healthy ash and another victim of EAB. Trees that are dead or dying should be promptly removed. Dead ash trees are brittle when they die, drop branches in low wind, and are more difficult to remove than living ash trees. These branches can damage property, injure bystanders, and have even killed. It is much safer, both for residents and for the arborists to cut ash trees down before they die.
EAB is the most costly forest pest to ever arrive in the US. The loss of ash trees harms both terrestrial and aquatic plants and animals. Green ash, which commonly grows along bodies of water like rivers and lakes, serves as habitat for wildlife, particularly birds, and, in Indiana, endangered species of bats and snakes. Ash trees also produce shade that cools rivers and lakes, improving the habitat for fish and other wildlife.
Infestations of EAB cause huge costs for replacement tree planting and maintenance programs, as well as reduce property values. The 2006 U.S. Forest Service statewide urban forest assessment program suggests that in urban areas of Indiana alone, there were 2 million urban trees worth approximately $2.9 billion in replacement costs.
No, but it may be possible to reduce its population size to manageable levels through a combination of pesticides and biocontrol efforts. Although it may seem hopeless, there are many examples of successful invasive species control efforts. You can read about some of them on the Washington state invasive species council website and the Great Lakes Connection website.
If you live within 15 miles of a known infestation (all of Indiana) you should follow the steps outlined in our EAB decision guide (pdf) for assessing ash trees and developing a response program. Follow guidelines in insecticide options for managing emerald ash borer.
Although emerald ash borer will never be eradicated you only need to treat trees aggressively until all the untreated trees nearby have been killed. After that time you should monitor your trees for fresh signs of injury. Typically this will be fresh woodpecker holes in the upper canopy or a new canopy thinning. Read more about this concept on our Invasion Waves page.
In most cases, studies have found that the risk to beneficial soil microbes, groundwater, and animals, including pollinators, is minimal when treatments are applied correctly. For more detailed information about the effects of EAB pesticides, please refer to the EAB pesticide side effects guide (pdf).
In addition to pesticide treatments, a biocontrol program has been put into place to try to control the population of EAB. To read more about it, see our management page.
EAB primarily attacks true ash trees (Faxinus spp.), but it has also been found on white fringetree (Chionanthus virginicus).
Although there is some promising work on developing EAB resistant ash cultivars, it is still unclear how successful these trees will be in the long term. Blue ash (Fraxinus quadrangulata) is native to North America and resistant to EAB. Manchurian ash (Fraxinus mandschurica ) is native to Asia and also resistant. Pesticide treatment is currently the most effective option for preserving other ash trees.
Many invasive species, including EAB, hitch a ride on firewood and spread much faster to new areas than they would be able to on their own. If we can stop people from moving firewood long distances, we will have a better chance of containing or eradicating many invasive pests. You can learn more about specific firewood regulations at the Don’t Move Firewood website.
Without human help, EAB only spreads about half a mile a year. EAB travels greater distances by hitching a ride in plant products like firewood, logs, and nursery stock. You can greatly slow the spread of EAB by not moving firewood.
It could be! If you can still see it or have a picture of it, try to make note of key characteristics like size, shape, color, and the kind of tree you found it on. Use our identification guide to determine if it is EAB or one of its look-a-likes.
If you are in Indiana, call the Indiana DNR at (866) NO-EXOTIC, email depp@dnr.IN.gov (include: your name, phone number, address, species seen, and the county where you saw it), or use the GLEDN app to report your GPS location and send a photo of what you have seen.
If you are not in Indiana, please refer to this list of state specific contact information or this list of available invasive species related apps.