"> City of Naperville City of Naperville

Emerald Ash Borer

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Emerald Ash Borer Awareness Week and Open House
Latest News
What is the Emerald Ash Borer?
Ash Trees
What the City is Doing to Prevent EAB Infestation
What You Can Do
Treatment Options for Private Ash Trees
Inform the City

Emerald Ash Borer Awareness Week
Friday, April 27, through Friday, May 4

Emerald Ash Borer Open House
Monday, April 30  - 6:30 to 8:00 p.m.
in Meeting Rooms B and C of the Municipal Center, 400 S. Eagle St.

City to Treat Ash Parkway Trees This Spring

The City will be treating all healthy ash parkway trees this spring for the Emerald Ash Borer. To track the City'mashups/eab/">Interactive Emerald Ash Borer map.

Emerald Ash Borer Awareness Week and Open House

In response to the devastating effects of the Emerald Ash borer (EAB), the City of Naperville is proclaiming Friday, April 27, through Friday, May 4, as Emerald Ash Borer Awareness Week which will include an open house for residents to learn more about the treatments being used to fight the beetle.

As part of EAB Awareness Week, the City will be hosting an EAB Open House from 6:30 p.m. to 8:00 p.m. on Monday, April 30, at the Municipal Center, 400 S. Eagle St.  Residents may stop in at any time during the open house to get information about the EAB and to learn about, the city’s EAB treatment program, as well as options that can be considered for treating private ash trees.

What are those ribbons? 

The City will be placing green ribbon around select ash trees throughout the community as a way to educate residents about ash trees and the EAB.  

Latest News (Last Updated March 16, 2012)

In an effort to address the growing number of ash trees affected by the Emerald Ash borer (EAB), the City of Naperville will be implementing an aggressive multi-year treatment plan for all healthy ash trees that are located in the City's parkways to reduce the devastating effect of the beetle in the community. If the City does not treat any of the parkway ash trees, we expect that all of the ash trees will be dead within five years.

The best time to treat ash trees and control the spread of the EAB is early spring to early summer. By getting the treatments into the tree in early spring, the chemical is moved up throughout the tree and is then ingested by the EAB larvae, which kills them thereby helping protect the tree from serious damage.

Beginning in April 2012, licensed contractors will be utilizing three types of treatments for the City's estimated 16,300 parkway ash trees.

  • Xytect™ (imidacloprid)
    The City will be using this treatment for most trees that are less than 20 inches in diameter. This annual treatment is applied as a soil injection around the base of the tree.
  • TREE-äge® (emamectin benzoate) 
    Used for larger trees, this treatment consists of a chemical application that is injected directly into the tree and lasts for two years.
  • Safari® (dinotefuran)
    A limited number of trees will be treated with Safari. This product is reapplied every year.

Homeowners with trees that receive treatment for EAB will be notified with a door hanger indicating what treatment has been performed. To protect trees this year treatments will be done in April, May and early June, and by July 15 if treated with TREE-äge®. Parkway trees that are badly infested will be removed and replaced. Residents will be contacted if their tree needs removal.

What is the Emerald Ash Borer?

Adult Emerald Ash Borer- Photo courtesy of The 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. Native to Asia, the beetle was first discovered in the summer of 2002 in southeastern Michigan and has since spread to a number of states, including Illinois.

The adult emerald ash borer emerges in mid to late May. Soon after they emerge, the adult females lay numerous eggs on the trunk and branches of the ash tree. The eggs hatch within 7-10 days and the larvae, which are creamy white in color, bore into the bark of the tree. The larvae begin to feed on the inner bark and create S-shaped galleries, which cut off the food and water supply to the tree, causing it to die.

Click here to read more about signs and symptoms of the emerald ash borer. Signs and Symptoms of EAB Brochure (PDF)

In June 2008, the City of Naperville received confirmation from the United States Department of Agriculture that the emerald ash borer was present in a portion of southwest Naperville, making this the first confirmed case of the emerald ash borer in Naperville and Will County. Since then most communities in the Chicagoland area have confirmed the presence of the beetle.

Visit the State of Illinois web site at or for more emerald ash borer information.

 Ash Trees

Ash trees, which are common in landscapes native to Illinois forests, are the most numerous species in the city’s parkway tree inventory, representing about 27 percent of the City's parkway tree inventory.

Characteristics of Ash Trees:

  • Ash trees feature compound leaves made up of small, glossy green leaflets
  • Leaves, twigs and branches grow in opposite pairs
  • Bark of mature ash trees is gray and furrowed, often appearing in a diamond pattern
  • Some ash trees will produce small canoe paddle-shaped seeds

Green Ash Leaf
Green Ash Leaf
[Photo courtesy of Dave Roberts, Michigan State University]

White Ash Leaf
White Ash Leaf
[Photo courtesy of Dave Roberts, Michigan State University]

What the City of Naperville is Doing to Prevent EAB Infestation

Since the beetle was first discovered in 2008, the City of Naperville developed a containment strategy that included inspection and inventory of all trees in infested areas. Traps were also installed to determine the extent of the beetle's presence. Treatment, removal and property disposal of all infested trees has also continued with more than 4,000 trees receiving treatment in 2011.

The City's Forestry section has worked in cooperation with the Illinois Department of Agriculture, DuPage and Will Counties, Naperville Park District and area townships to implement its containment strategy, which includes treatment of all healthy parkway ash trees in 2012.

The City's Forestry section has eleven certified arborists that are trained to look for signs of the presence of the emerald ash borer and actively check ash trees everyday during their regularly scheduled work. The City's Forestry section will continue to evaluate all parkway ash trees and remove any diseased or weakened trees in an effort to reduce the overall percentage of ash trees in the City's urban forest.

Residents are encouraged to report sick or dead trees by calling (630) 420-6095.

What You Can Do

Treatments Options for Private Ash Trees

There are several treatments for EAB control (Insecticide Options for Protecting Ash Trees from Emerald Ash Borer.)

It is recommended residents get more than one estimate to help make an informed decision. Tree owners are encouraged to thoroughly research the various treatment options currently available and carefully weigh the costs associate with the required repeated treatments.

The City of Naperville is providing a qualified vendor list as a resource to residents who would like to treat their private trees. The list is subject to change.

Use this tool to calculate the economic and ecological benefits of your tree.

Research has been ongoing since the borer first arrived in this country and many trees are being saved. The healthier the tree is when treatment begins seems to be a large factor in the survival of the tree. Treatment of an ash tree will not guarantee that a specific tree might not eventually be required to be removed should it decline due to the borer. Certified arborists can determine the health of an ash tree and whether treatment is viable.

Ash trees that are not treated will succumb to the EAB. To ensure the insecticide is in the trees by the time adults emerge to feed in early June, products are most effective when applied mid-April until mid June, or mid July with TREE-äge®. Trees over 15 inch diameter should be treated professionally. The strength of the chemical in the home product is less than the product available by professional arborists. The applications of emamectin benzoate (TREE-äge®), imidacloprid (Xytect™), or dinotefuran (Safari®), which moves through the tree, are more likely to provide useful control. These options require a licensed professional to apply the insecticidal control to the tree.

See the document Insecticide Options for Protecting Ash Trees from Emerald Ash Borer (PDF) for the most up to date research on Emerald Ash borer control options and effectiveness.

Inform the City

While the City will treat all healthy parkway ash trees, it is beneficial and helpful to the City's Forestry Section to document the treatment of private ash trees so the future treatment and containment can be improved upon for the City as a whole.

If you decide to treat any ash trees, please print and complete the Emerald Ash Borer Treatment Form (PDF) and return it to the Department of Public Works each time the tree is treated so that it can be stored in a database. An electronic version of the treatment form is now available. Complete the Emerald Ash Borer Treatment Form - Electronic Version (PDF) online to submit by email. If an arborist identifies an emerald ash borer infested tree anywhere on your property, please notify the Department of Public Works at (630) 420-6095.