Emerald Ash Borer
Community Fact Sheet
The Emerald Ash Borer (EAB) is an exotic woodborer that was found to be attacking and killing ash trees in Michigan in 2002. The Emerald Ash Borer only attacks ash trees and is a devastating and destructive pest that greatly affects the urban forest. EAB is easily spread through the movement of firewood, logs and nursery stock.
Since its detection, EAB has killed millions of ash trees and has spread into Indiana, Ohio, Illinois, Wisconsin, Iowa and other states. Discovered in Illinois in 2006, EAB has since spread throughout northeast Illinois into the nearby towns of Geneva, Batavia, North Aurora and Naperville as well as other locations in and around LaSalle and Bloomington.
The first confirmation of EAB in Aurora was found in a “trap” tree located on the city right-of-way on Liberty Street just west of Route 59 in Du Page County in 2008. Since this initial confirmation, the EAB has spread throughout the City. The EAB infestation has been more prevalent on the City's Far East side and in other subdivisions built since the 1970s. Those areas tend to have a denser population of ash trees because they were deemed hardy and affordable to plant at the time.
The City’s response to EAB now that is has been discovered in Aurora:
- Ash trees, located on city-owned property including parkways, showing signs of infestation will be removed and disposed of in accordance with Department of Agriculture protocol.
- Aurora has adopted a selective ash tree removal strategy on city-owned property as a management plan to help mitigate and control the spread of EAB. Selective ash tree removal has been the preferred strategy used by the majority of communities with confirmed EAB infestation. Ash trees located near confirmed sites that exhibit positive signs of EAB infestation – e.g. canopy dieback, sprouting near base of tree, woodpecker holes - will be removed. At this time, the City will not be removing healthy looking ash trees.
The City of Aurora has prepared for the arrival of Emerald Ash Borer by:
- Monitoring for EAB by inspection of all city owned ash trees removed due to accidents, poor / declining health, as part of an overall ash tree reduction plan.
- Replacement with a diversified selection of trees (no ash trees will be used for replanting).
- Testing for the presence of EAB through a cooperative effort between the City of Aurora, the Illinois Department of Agriculture and the Morton Arboretum. Thirty ash trees throughout the City were selected as “trap” trees for the purpose of Emerald Ash Borer detection.
- Implementation of a Trapping Program in 2008 that uses insect lures to determine if EAB is present in the City.
- Updating City ordinances to include specifications about ash trees and EAB.
- Providing training to city staff who will respond to EAB.
- Developing a public awareness campaign including publications and information about the Emerald Ash Borer.
Homeowners should prepare for the possible arrival of EAB within their own yards. Homeowners should stay informed regarding the location of any local EAB-infestations and should periodically examine their trees. If any signs of an EAB infestation are present, homeowners should contact:
- City of Aurora Customer Service Division at (630) 256-INFO (4636)
- A local professional arborist
- The local University of Illinois Extension Service office. Find the closest office at http://web.extension.uiuc.edu/cie2/offices/findoffice.cfm, or by calling (217) 333-5900.
- National EAB Hotline: (866) EAB-4512
If, after consultation with a local expert, an EAB infestation is suspected, you should contact the Illinois Department of Agriculture HOTLINE at (800) 641-3934.
STAY INFORMED AND FOLLOW DIRECTIVES FROM THE ILLINOIS DEPARTMENT OF AGRICULTURE. Check for periodic updates at these Web sites:
Insecticide Options for treating Ash Trees
Chemical treatment options do exist but have not been proven to be 100% effective. Consult a local garden center or Arborist for information. This PDF bulletin is designed to answer frequently asked questions and provide the most current information on insecticide options for controlling Emerald Ash Borers.
Signs to Look for
Ash Leaves
Ash leaves are somewhat unique since they have several green leaflets per leaf stem, usually seven. The leaflets are located directly across from each other with one at the end.
Emerald Ash Borer
The Emerald Ash Borer is an exotic beetle from Asia. Though small (approximately 1/2 an inch), it can fly up to a mile from where it emerges.
D-Shaped Exit Holes
D-shaped exit holes can be found on trees where the adult beetles emerged. A tree with these holes has been infested for at least one year. They will be present on the branches and the trunk.
Suckers
“Suckers,” or new sprouts, may develop around the bottom of the main trunk of an infested tree. They can grow until they are 2-3 inches in diameter and are again attacked by the Emerald Ash Borer.
Tree Canopy
Tree canopy will begin thinning and branches will die. First there will be yellowing of the leaves, then dead branches. The thinning will begin at the top third of the tree, then spread over time. Usually, a tree will live two to four years after thinning at the top of the tree occurs.

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