Gypsy Moth Alert!

Illinois has been losing the battle against the tree-killing gypsy moth in Cook, DuPage and Lake Counties. As gypsy moth caterpillars invade Northeastern Illinois from other states, a meaningful eradication program has become impractical in this area. As a result, the Illinois Department of Agriculture (IDA) is shifting its aggressive spraying efforts to less-infested counties and discontinuing its focused eradication program in Cook, Lake and all but the southwestern portion of DuPage.

University of Illinois Extension is assisting IDA with public education about gypsy moth identification and control methods. Extension has developed a fact sheet on the subject and Master Gardeners at local Extension offices will answer questions over the phone.

Infestations in Lake County have risen to such a high level that the county is now under a quarantine that restricts movement of nursery stock, firewood, household belongings and other materials out of the area. The rise in gypsy moth populations throughout Northeastern Illinois is widely attributed to a migration of caterpillars from infested areas of Michigan and Wisconsin.

Tree species that are highly susceptible to gypsy moth attacks include oak, crabapple, linden, poplar, beech, willow, birch, sweetgum, serviceberry and hawthorn. Other trees that may be infested include pine, spruce, ash, sycamore, Indian bean, honeylocust, dogwood, juniper, yew, lilac, arborvitae, arrowwood, viburnum and tulip tree.

At this time of year, gypsy moths have laid their egg masses and most of the adult moths are dead. The egg masses are about one inch long by one-half inch wide and resemble buff-to-tan-colored felt patches. Females lay egg masses on tree bark and other exposed surfaces, as well as in hidden locations, including under loose bark, beneath house siding, within hollow areas of swing sets and in car wheel wells. Egg masses should be scraped off and dropped into rubbing alcohol or soapy water. Dispose of them in the trash.

In the spring when the eggs hatch, spray applications are recommended and most effective at the time when leaves on oak trees are expanded about halfway. In Northeastern Illinois, this is usually in mid-May. Insecticides that are effective against the moth larvae include Bacillus thuringiensis kurstaki (Dipel, Thuricide), cyfluthrin (Tempo), diflubenzuron (Dimilin), tebufenozide (Mimic) and others.

A factsheet describing the gypsy moth and control methods is available on the University of Illinois Extension Urban web site at www.urbanext.uiuc.edu/gypsymoth or call 773-233-0476.

 

Autumn 2000
Gypsy Moth Alert! | All-America Flower Selections 2001 | Fall-Blooming Perennials Make Your Garden Last Year Round | Tips on How to Avoid Plant Diseases | Bug Bites: Yellowjackets | Cybergarden Sites | Hort Shorts | Hort Tips | Locally Grown: Making Chutney | Consider Using a Humidifier This Fall | Cholesterol Awareness Month | Health & Household Tips | Did You Know?

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