Emerald Ash Borer - City of Oak Forest

Emerald Ash Borer: Presentation and Brochure

City of Oak Forest Ash Tree Survey (Parkway Trees)

In December 2009, Emerald Ash Borer (EAB) was discovered in an ashtree within the city limits at Corey Drive and Terrace Drive. The ash tree was exhibiting classic signs of EAB infestation so a sample was taken and sent to the Illinois Department of Agriculture for confirmation. The city's certified arborists are moving quickly to formulate a plan in conjunction with the United States Department of Agriculture, Illinois Department of Agriculture, and the Forest Preserve District of Cook County to deal with the infestation and decline of the city's ash tree population.

What is EAB?

EAB is a non-native species to North America. It is believed to have been brought here from Asia in 2002. Adult beetles are bright, metallic-green in color. Adults are one-third inch long and one-sixteenth-inch wide. They have rounded abdomens and flat backs and are present from mid May through late July. Larvae are creamy white and have flattened, segmented bodies. Older larvae grow up to an inch long. They feed under ash tree bark from mid summer through spring, damaging the ash tree's vascular tissue. These beetles only infest ash trees.

EAB Adult

EAB Larvae

What does an ash tree look like? Ash trees can be identified by:

1. Diamond shaped bark

2. Branches that grow opposite of one another

3. A compound leaf composed of seven leaflets

How do I know if my tree has EAB? Infested trees have:

1. Canopy dieback (healthy tree, left - dieback, right)

2. D-shaped exit holes

3. Excessive sprouting or growth at base of tree

4. Splits or fissures on the trunk of the tree

What can I do if I suspect my tree is infested?

If the tree is on the parkway you may contact the Public Works Department at 708-535-4090. If the tree is on private property one of the city's certified arborists can inspect your tree if they are available or you can contact a certified arborist who will examine your tree for signs of infestation.

If my tree is infested what can I do?

The United States Department of Agriculture recommends removal of any EAB infected trees. You do have the option of having your tree treated by a professional with a variety of products (Professional Treatment Options) or doing it yourself. (Homeowner Guide to Emerald Ash Borer Treatment) It is important to note that these treatments are no guarantee that the tree will survive. Once there is 50 percent or more dieback then the tree is unable to be saved and must be removed.

Bulk Firewood

Because of the Emerald Ash Borer, Public Works will be removing approximately 1,800 trees from city parkways. If any resident is interested in receiving logs, please contact Public Works at 708-535-4090. Residents will need to sign a waiver stating that they want the wood delivered to their residences. The city is not responsible for any damage caused by the delivery. Please note that this is not split wood.