Much More On The Emerald Ash Borer

Frequently Asked Questions about Emerald Ash Borer


What is Emerald Ash Borer?

Emerald ash borer (EAB) is a highly invasive, non-native insect that attacks and kills all species of North American ash trees, including white, green and black ash. EAB is native to Asia and was first detected in the United States in summer 2002 feeding on ash trees in the Detroit area. As of June 2, 2010, EAB has not been confirmed in the northern Plains (Kansas, Nebraska, North Dakota and South Dakota).

What does EAB look like? Adult EABs are emerald green beetles that areapproximately 1/2 inch long with slender, elongatebodies.EAB larvae can grow up to 1 ¼ inch long and are white or cream colored. They have brown heads and a 10-segmented body with a pair of brown, pincer-like appendages on the last segment.

What does EAB do?

EAB larvae feed on the tissues just below the bark. As they feed, larvae create serpentinetunnels, also called galleries, that disrupt the tree’s ability to transport water and nutrients and eventually kills the tree.EAB adults typically emerge during June and July, leaving D-shaped exit holes in the bark. After emerging, the adults feed on ash foliage and can live for approximately three weeks.

What are symptoms of EAB?

Symptoms of EAB include canopy dieback, beginning in the top one-third of the canopy, sprouting from the base of the tree and trunk, bark splitting, serpentine galleries below the bark, D-shaped exit holes and increased woodpecker activity. Crown diebackSprouting from baseSerpentine galleriesWhat species of trees does EAB attack? EAB attacks and kills all species of North American ash, including white, green and black ash. Mountain-ash is not a true ash, so it is not threatened by EAB.

How do I identify an ash tree?

Ash trees exhibit an opposite leaf pattern, meaning that leaves and buds are located directly across from each other. Ash leaves arecompound and typically consist of 5-11 leaflets. The edges of theleaflets may be smooth or toothed. On mature ash trees, the bark has a distinct pattern of diamond-shaped ridges. Younger trees have smoother bark.When seeds are present, they appear in paddle-shaped clusters that stay on the treeuntil late fall or early winter. Where is EAB from originally?EAB is native to Asia.

When did EAB get to the U.S.?


EAB was first detected in the U.S. in summer 2002, feeding on ash trees in the Detroit area.How is EAB spread? EAB is spread primarily through the transport of infested firewood, ash wood products and nursery stock. Moving firewood and other ash wood products within areas infested by EAB and out of infested areas is regulated by state and federal agencies. To help prevent the spread of EAB, and other wood-dwelling invasive pests, collect or purchase local firewood at your destination. For more information, visit


What can I do to prevent spreading EAB?

EAB is most commonly transported into new areas on infested firewood. To help prevent spreading EAB, as well as other wood-dwelling invasive pests, collect or purchase local firewood at your destination. To learn more, visit Where has EAB been detected?As of June 2, 2010, EAB has been detected in Illinois, Indiana, Iowa, Kentucky, Maryland, Michigan (both the upper and lower peninsulas), Minnesota, Missouri, New York, Ohio, Pennsylvania, Virginia, West Virginia, and Wisconsin. In Canada, EAB has been detected in Ontario and Quebec. For up-to-date maps showing infested states, as well as quarantines, pleasevisit


Can anything be done to prevent EAB from killing ash trees?


Unfortunately, nothing can be done to stop EAB from spreading into new areas and killing ash trees there. In the next several years we may have new methods for slowing EAB’s spread, butthese will only slow its spread, not stop it. In areas where EAB is present, insecticide treatments can be used to protect high-value trees, such as large shade trees, historic trees and trees highlyvalued by homeowners. Researchers are currently working to develop new treatments for EAB.

Is there a treatment for EAB?

Insecticide treatments can be effective in protecting trees from EAB. The treatment available forhomeowner use is a soil application of imidacloprid (such as Bayer Advanced Garden TM Treeand Shrub Insect Control). The application should be made in May and is most effective on smalltrees. Tree care professionals are able to use additional products such as trunk injections and trunk and foliage sprays. More information about available treatment methods can be found on the Internet at and

Should I treat my ash tree before it gets EAB?

No treatment is needed until EAB has been found within 15 miles of your tree. If your tree has symptoms like those of an EAB infestation, such as canopy dieback or borer exit holes, you maywant to have a tree care professional examine the tree. To locate a certified arborist in your areaplease contact your local city forester.

Should I remove my ash tree before it gets EAB

?If your tree is healthy, there is no reason to cut it down. If it is dying or diseased, it may be bestto hire a certified arborist to look at your tree and determine whether it has EAB or another insect or disease problem. There are a number of native insects that attack ash trees and may causesymptoms similar to EAB. Just because your ash tree shows symptoms like those caused byEAB does not mean it has EAB. However, with highly destructive invasive insects, such as EAB, it is best to err on the side of caution by seeking professional guidance if you suspect your tree is infested. If EAB becomes established in your area, management steps may need to be taken.

Should I continue planting ash trees?

Given the threat of EAB and the over-abundance of ash, the further planting of ash is notrecommended. Ash has been popular in landscape, agroforestry and conservation plantings fordecades. However, this popularity has resulted in a tremendous number of ash trees in communities throughout North Dakota and the northern Plains. Because species diversity is an important measure of a community forest’s overall health, it is important to plant a variety of treespecies. There are a number of trees that grow well in North Dakota, but are frequently under planted. For recommendations about what trees you can plant in your landscape, contact your local North Dakota Forest Service office. Are there any ash varieties or cultivars that are resistant to EAB?Preliminary research does not indicate that there are any resistant ash varieties or cultivars native to the U.S., but research is continuing.What are alternatives to ash? In many urban areas there are ordinances that outline what types of trees can be planted so it’s agood idea to check with your local city forester for planting options. Reputable local nurseries orgreenhouses are also excellent sources of information. You can also contact your local SoilConservation District, Extension office, or ND Forest Service office for more information on rural tree planting options.


What other insects attack ash trees?

There are several species of native ash borers that attack ash trees. In North Dakota the ash lilacborer and carpenterworm are known to be able to attack healthy ash trees. Stressed ash trees aremost commonly attacked by the redheaded ash borer and ash bark beetle. For more information about these insects, see Michigan State University Extension Bulletin E-2939, Native Borers and Emerald Ash Borer Look-alikes.What other insects look like EAB?There are multiple species of insects that are frequently mistaken for EAB. The bronze birch borer looks very similar to EAB and even presents similar symptoms. However, this borer attacks stressed birch trees. The six-spotted tiger beetle, two-lined chestnut borer, and caterpillarhunter are all similar in color to EAB. For more information about these insects, see Michigan State University Extension Bulletin E-2944, Don’t be Fooled by Look-Alikes.

Where can I learn more about EAB?

More information is available from your state forestry agency or state department of agricultureand on the Web at

Who should I call if I think I have EAB on my tree?

If you suspect you have EAB the first step is to make sure you are dealing with an ash tree. Then you need to contact your local city forester if you are in an urban area, in rural areas contact theSoil Conservation District, NDSU Extension office, ND Forest Service or the ND Department of Agriculture. If you can provide samples from the tree, suspect insect specimens or photos ofparts of the tree and/or insects they can be a great help in identification.


What is being done in North Dakota to prepare for EAB?

North Dakota is involved with the Great Plains Tree and Forest Invasives Initiative (GPI), acollaborative initiative of state forestry agencies in Kansas, Nebraska, North Dakota and South Dakota and the US Forest Service. States are inventorying tree and forest resources to determinewhich areas may be most impacted by EAB and other invasive species, developing publiceducation programs, and exploring opportunities for utilizing wood generated by EAB. Thereare numerous entities involved in strategizing the state response plan for EAB. The plan includes outreach and education activities, detection processes, and responses if the insect is found within the state. This is a high priority issue for USDA APHIS, ND Department of Agriculture and the ND Forest Service. H