District Fights Defoliation Caused by Gypsy Moth Infestation

The devastation caused by gypsy moths is evident in yards, parks and forest preserves. The tiny flying foes of foliage can strip acres of trees quickly and efficiently, and, they appear to be increasing in numbers. DuPage County and neghboring counties including Cook, Lake and McHenry, are coping with the most recent wave of infestations.

As the gypsy moth infestation spread across northern Illinois in 2007, state-wide preventative programs have had to reduce seasonal spray treaments for DuPage County. As a result, last spring the Forest Preserve District of DuPage County stepped up efforts to ward off gypsy moth infestations for 2008. In addition, the District is preparing for 2009, tracking current infestations and preparing for the next opportunity to suppress the gypsy moth and protect DuPage County's forest preserves.

What are gypsy moths and how are they hurting trees?

The gypsy moth is a nonnative insect that, in its caterpillar stage, feeds voraciously on the leaves of oak trees causing striking defoliation. If an oak suffers from severe infestation several years in a row, the stress can kill the tree. For more information about gypsy moths, caterpillars and egg masses, read "The Gypsy Moth Arrives in DuPage County," in The DuPage Conservationist, the District's award-winning quarterly publication.

Where are gypsy moth infestations?

Summer 2008 reports of infestations include Timber Ridge, Waterfall Glen, Maple Grove, Fullersburg, Cricket Creek, Fischer Woods, York Woods and Blackwell. According to the District's Office of Natural Resources, many of these areas have at least a few trees that are completely defoliated. Infestations at Herrick Lake and Winfield Mounds defoliated approximately 10 acres of trees last season.

What is the District doing to prevent gypsy moth infestations?

The District successfully treated two known infestation areas with Btk, Herrick Lake and Winfield Mounds, the last week of May 2008. Btk is a naturally occurring bacterium that targets gypsy moth caterpillars. There is only a small window of opportunity to spray in spring of each year, however, as Btk is not as effective when the caterpillars reach full size. The District's Office of Natural Resources is preparing for next season's treatments by keeping track of new and existing infestations. A monitoring and surveillance program throughout the year will identify areas of concern to maximize suppression in 2009.

What species of tree are at risk of defoliation from the gypsy moth?

The gypsy moth feeds on a wide variety of trees. Preferred species are oak, apple, crab apple, aspen, cherry, hawthorn, plum, pear, poplar, river birch, white birch and willow. Moderately preferred species include cottonwood, elm, hickory, maple, pine, redbud, sassafras and spruce. Trees that are generally resistant to attacks are arborvitae, ash, balsam fir, black walnut, catalpa, locust, red cedar, sycamore, tulip poplar and walnut.

How can I help the District fight gypsy moth infestations?

The District's Office of Natural Resources tackles the on-going tracking, surveillance and trapping of gypsy moths. While most citizens will see minor infestations on trees in their area or in preserves, it's key to spot massive infestations early. If you know of any defoliation in areas in or around the District's Preserves, please email us at forest@dupageforest.com, or call (630) 871-6402. The University of Illinois is also running a Northeast Illinois Reporting Site, where you can register and post local sitings of gypsy moths in Illinois.

No method of treatment will completely eradicate the gypsy moth. What DuPage County residents should learn from these recent reports, above all else, is that we must learn to live with the gypsy moth. Their populations will boom and bust and are now a part of the local natural environment. The Gypse Moth is here to stay, the goal is to minimize its adverse effects on the County's natural foilage.

With over 25,000 acres, 140 miles of trail and 60 preserves all right at your feet, there's a perfect way to enjoy DuPage County's forest preserves that's just waiting for you. For information, call (630) 933-7200, or visit www.dupageforest.com.