Signs of EAB
Early detection of an EAB infestation is difficult. If you want to protect your ash against EAB, preemptive treatment is strongly recommended. This will remove the burden and worry of being on constant lookout for the signs and symptoms of an infestation. Unless you keep a careful watch on your tree and know exactly what to look for, you run the risk of not detecting an infestation early enough for insecticide treatment to work. If you decide to postpone treatment and are willing to diligently monitor your ash for EAB, you could detect an infestation early enough for insecticides to work.
The following visual aids show the signs and symptoms of an infestation that you need to be on the lookout for:
The following visual aids show the signs and symptoms of an infestation that you need to be on the lookout for:
- Watch these videos:
How to Identify Signs and Symptoms of an Infested Ash Tree
How to Identify the Emerald Ash Borer Beetle - Pick up a wallet-size, laminated card with pictures of EAB signs and symptoms available on the kiosk in the City Hall entranceway. (Cards with pictures on how to identify an ash tree also are available.)
- Print one or both of these handy, illustrated guides for homeowners:
EAB Signs and Symptoms-1
EAB Signs and Symptoms-2
- An adult EAB beetle is bullet shaped and about one-half inch long and one-eighth inch wide. Its back is dark metallic green, and its underside is bright emerald green. See the link below for look-alikes. Photo by Renee Pinski, WDNR.
- The violet-colored abdomen of an adult EAB beetle flaring its wings. Photo by David Cappaert, Michigan State University, Bugwood.org.
- Bark flecking caused by woodpeckers is likely the first sign of an EAB infrestation. Jagged holes and patches of flecked off bark could mark spots where woodpeckers have repeatedly drilled for EAB larvae. Photo by Steven Katovich, USDA Forest Service, Bugwood.org
- Thinning of a tree's canopy or dieing branches could indicate the presence of EAB. Branch dieback alone can be caused by a variety of natural diseases and insects. EAB is more likely if suckers (sprouts) also appear anywhere on the tree below dead branches. A tree sends out suckers to compensate for lost foliage. Photo by Jane Cummings Carlson, WDNR.
- Vertical bark splits on the trunk develop in areas where larvae have fed, often revealing their S-shaped excavation paths. This usually points toward an advanced infestation as larvae have bored inward from eggs deposited on the trunk. Most branches are dead so larvae must feed where food is available. Photo by Linda Williams, WDNR.
- When an EAB beetle emerges (late May-mid July), it leaves behind a D-shaped exit hole, about one-eighth inch in diameter. Holes can be oriented in any direction and found anywhere on the trunk. Also check lower branches. Look for holes if you notice any other signs or symptoms of an EAB infestation. Photo by Renee Pinski, WDNR.
Early detection of emerald ash borer is difficult, especially on large trees, because beetles attack the top first. Furthermore, dieback of branches in the upper crown can be caused by insects other than EAB. Unless a tree is heavily infested, chances of seeing an adult EAB beetle are extremely rare. Nevertheless, be aware that if you spot a green beetle on an ash trunk, branch, or leaf it could be EAB or it might be a look-alike beetle.
If you are sure you have an ash tree and notice signs or symptoms of EAB on it, please first call the City Forester. If he is unavailable, leave a message and call the Director of Parks, Recreation, and Urban Forestry. Leave a message if necessary. If you speak with neither directly, then call the Department of Agriculture, Trade, and Consumer Protection’s EAB hotline. E-mailing digital photos of your tree to the City Forester or Parks Director is encouraged.
Anna Healy, Fitchburg City Forester
608-270-4289
anna.healy@fitchburgwi.gov
Scott Endl, Director of Parks, Recreation, and Urban Forestry
608-270-4288
scott.endl@fitchburgwi.gov
Wisconsin Department of Agriculture, Trade, and Consumer Protection EAB Hotline: 1-800-462-2803
Reporting EAB
If you are sure you have an ash tree and notice signs or symptoms of EAB on it, please first call the City Forester. If he is unavailable, leave a message and call the Director of Parks, Recreation, and Urban Forestry. Leave a message if necessary. If you speak with neither directly, then call the Department of Agriculture, Trade, and Consumer Protection’s EAB hotline. E-mailing digital photos of your tree to the City Forester or Parks Director is encouraged.
Anna Healy, Fitchburg City Forester
608-270-4289
anna.healy@fitchburgwi.gov
Scott Endl, Director of Parks, Recreation, and Urban Forestry
608-270-4288
scott.endl@fitchburgwi.gov
Wisconsin Department of Agriculture, Trade, and Consumer Protection EAB Hotline: 1-800-462-2803