The implementation of an Integrated Pest Management (IPM) program is the best way to keep tree diseases and insects under control. This plan hinges on the idea that in an ecosystem, a certain level of insects and disease is naturally present and that the chemical eradication of these organisms may disrupt a delicate balance in nature. The plan calls for the establishment of damage/economic thresholds to determine at what point chemical application of pesticides is warranted, and ensures that the purpose of this chemical application is only to keep pest populations within these thresholds.

There are many different components to an IPM system. Scouting for the early identification of plant problems, cultural practices that increase tree vigor, selection of species resistant to pest problems and the use of biological controls all play a role in reducing chemical pesticide applications and lead to a healthy urban forest.

Forestry staff continues to actively scout for and follow-up on all calls about exotic tree pests in the Village.  The Dutch Elm Disease Program includes disease scouting, tagging, notification, follow-up inspections and assistance with the disposal of diseased material.  We continue to comb the Village in search of Emerald Ash Borer as well as Gypsy Moth.  During the spring of 2009, the Village contracted with Hendrickson Flying Service to conduct aerial spraying in Hickory Haven to curtail a growing population of Gypsy Moth that had been attacking a stand of mature oaks.  Forestry staff conducted several follow-up inspections of this neighborhood during the summer months and, by all accounts, the spray program was a resounding success.

Two particular areas of concern to the Forestry Crew:

Potentially one of the most destructive invasive pests ever introduced into the United States, Emerald Ash Borer (EAB) has taken a massive toll on the Village’s urban forest. First discovered in southeastern Michigan in 2002, EAB has rapidly spread across the Midwest, killing millions of ash trees. The Village’s first confirmed infestations were found in the Boulders & Spruce Pointe subdivisions in December 2010 and have taken hold across the Village. Emerald Ash Borer

Since 2011, the Village has actively combated EAB through preserving public and parkway ash trees with chemical injections and educating the public on the seriousness of the problem. However, now that a significant amount of time has passed since the first infestations, the Village believes most, if not all, untreated ash trees are beyond the point of saving and will be dead in the near future. To ensure these trees don’t become a hazard to life and property, the only option left for property owners will be to remove these trees.

The information on this page is intended to give residents, business owners and property managers the necessary tools to understand and address EAB infestations. 

What is the Emerald Ash Borer?

EAB is a wood-boring beetle from Asia that feeds on ash trees.  Adult beetles are metallic green and about ½ inch long.  Once introduced into an area, the adult beetles lay eggs in ash trees. The larvae bore into the tree and literally strangle it by damaging the tree’s vascular system, or the main circulatory system of the tree. Within two to three years, the tree dies and becomes brittle. If the tree is not removed at this point, it could become a public safety hazard.

 Is my tree an Ash species?

While there are several different ash species, they share some common characteristics. Ash leaves are perhaps the easiest way to identify if a tree is an ash. These leaves will have 5-11 smaller leaflets attached that grow directly across from each other and are either smooth or have very fine "teeth." Aside from these leaves, older ash trees will have a distinctive diamond-shaped bark while younger trees will have a smooth bark surface. Finally, ash trees have dry, oar-shaped seeds that hang in clusters from the tree until falling in late fall.

What are the signs and symptoms of EAB?

Most untreated ash trees in the Village will be in a mid to late stage of decline. At this point, the tree’s canopy will either be very thin or nonexistent with branches that look brittle. The base of the trunk may also be “sprouting,” in which new sprouts begin shooting out.

Why should I be concerned?

EAB is a particularly concerning for two reasons: (1) it will kill any untreated ash tree and (2) there are likely thousands of ash trees on private property across the Village. Ash is native to Illinois and was popular for a number of years as a shade tree for both public parkways and private property.  In addition to the 2,400 known ash trees in the Village’s parkways, there are likely thousands more on private property.  Those who have not treated their ash tree will now need to remove them to prevent hazardous situations.

What can I do to address the problem? 

At this time, property owners have one option: tree removal. The Village recommends all property owners have their work completed by a contractor who has signed the State of Illinois’ EAB compliance agreement. This agreement outlines how to handle infested wood to slow the spread of EAB. As when signing any other contract, the Village encourages all residents to seek multiple quotes, ensure that the contractor is fully insured and check the references of any contractor performing work on their behalf.

What is the Village doing to address the threat?

In many respects, the Village has been fortunate to have the advantage of time.  Since the early 2000's, the Village has diversified the types of trees it plants in the right-of-way or offers through the 50/50 Parkway Tree program.  As part of that diversification, no ash trees have been planted on Village property since 2001.  Further, the Village has been planting new trees in areas of high ash density, which will ease the aesthetic damage done by EAB in those areas.

The Village also implemented an aggressive and successful chemical treatment program to protect public ash trees from EAB in 2011. The program called for the Village to save as many ash trees as possible while selectively removing and replacing trees that were already too damaged for treatment. To date, approximately 1,700 chemically treated ash trees remain in the parkway and have no signs of decline. Staff also worked to educate the public about the danger of EAB and a number of property owners did independently opt to treat their trees.

Further Resources:

Lake County has been quarantined since 2000 to slow the spread of Gypsy Moth. Gurnee forestry staff conducts routine inspections throughout the Village to identify potential infestations. When Gypsy Moth populations reach damaging levels, the Village may implement aerial and ground spray applications to control these areas.

What is Gypsy Moth?

Gypsy Moth is an exotic insect pest introduced to the United States in 1869 in Massachusetts.  Since then it slowly spread through the native forests of the eastern United States.  When local populations of Gypsy Moth grow, widespread defoliation can transpire causing tree decline and death.  Since Gypsy Moth has few native predators, it is often necessary to employ pest management programs to keep their population within acceptable thresholds.

Is Gypsy Moth in Gurnee?

Lake County has been under quarantine since gypsy moth first appeared in 2000. During the summer of 2008, the Hickory Haven neighborhood and a retention area near Grand Avenue and Fuller Road experienced an outbreak that led to the defoliation of several mature oak trees.

Where can I find additional information about Gypsy Moth?

Additional information about Gypsy Moth, the Village’s pest management program and our community forestry efforts is available on the Village website or by calling the Public Works Department at (847) 599-6800.

What can I do to help?

Please help us by reporting any tree pest or disease sightings in your area. Only with your help can we preserve our urban forest for generations to come.

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