Emerald Ash Borer

Emerald Ash BorerEmerald Ash Borer Background InformationThe Emerald Ash Borer (EAB) is a small (1/2 inch long, 1/8 inch wide) metallic green beetle that has killed millions of ash trees across the Midwest and into Canada. Ash trees are very common in landscapes and most species, namely white ash and green ash, are native to Illinois forests. Pictures of various types of ash trees can be viewed at the Morton Arboretum website.

Infestation of Emerald Ash Borer can be very difficult to detect until the branches of an infected tree begin to die. The most visible sign that the EAB is present is crown dieback, which appears after the first year of infestation. Usually the leaves on the upper third of the tree will begin to thin and the branches will begin to die. A number of suckers and branches will also sprout from the base of the tree and on the trunk. The bark may split vertically and woodpeckers may begin to feed on the beetle larvae leaving visible damage on the bark. Adult beetles emerging from trees will leave a very small 1/8 inch diameter distinctly D-shaped exit hole that may appear anywhere on the trunk or upper branches. Distinct S-shaped larval feeding tunnels may also be apparent under the bark. Typically, the tree will die in about three years.

Village Mitigation EffortsBeginning in 2007, the Village created a plan responding to Emerald Ash Borer (EAB) with the goal of the work to keep a full canopy of trees while reducing the number of ash and further diversifying the inventory. Dutch Elm Disease, Oak Wilt, and now Emerald Ash Borer, are all examples of a specific pest that attacks a certain species of tree which strengthens the argument for a widely diverse canopy. Ash trees were a popular parkway tree choice in the Midwest due to its ability to thrive in urban environments while being salt tolerant.  While Woodridge was not as extreme as some communities, ash still constituted over 20% of the Village owned inventory.  To date, approximately 2,500 ash trees have been removed and 2,300 replaced.  The Village continues to monitor the health of all trees and partners from time to time with the Morton Arboretum for guidance and to conduct research.

DetectionEmerald Ash Borer, and other borer infestation, is difficult to detect, especially in newly-infested trees. Individuals should watch for metallic-green beetles about half the diameter of a penny on or near trees that are showing signs of disease or stress. Other signs of infestation in ash trees include D-shaped holes in the bark of the trunk or branches and shoots growing from its base. If considering treatment of trees with insecticide, you are encouraged to learn the facts and make an informed choice based upon your circumstances. The Morton Arboretum website carries a fact sheet on insecticides that will help homeowners consider their options.
Anyone in Woodridge who suspects a tree has been infested is urged to contact the Public Works Department at 630-719-4753 and for more information Illinois Extension Office's website.

Do Not Transport FirewoodEmerald Ash Borer can easily be transported in ash logs. Make sure to purchase firewood locally from a known source and be sure to use all of the firewood in the cold months so that no hidden Emerald Ash Borer larvae or adults can survive on logs left through the spring.