1997 Forest Health Highlights, Illinois
The Resource
Illinois forests have many recreation and wildlife benefits. In addition, over 37,000 people are employed in primary and secondary wood processing and manufacturing. The net volume of growing stock has increased by 40 percent since 1962, a reversal of the trend from 1948 to 1962. The volume of elms has continued to decrease due to Dutch elm disease, but red and white oaks, along with black walnut, have increased by 38 to 54 percent since 1962.

Major Forest Types - Illinois

Special Issues
The first gypsy moths caught in Illinois occurred in 1973 when 5 moths were captured. The trap numbers remained low until 1981 when 2,753 moths were trapped, most of these in the Chicago area. At that time Bacillus thuringiensis was used successfully and the numbers remained in the hundreds until the early 1990's. Since 1994, the numbers exploded. In 1997, 34,816 moths were caught versus 2,633
Gypsy Moth Chart - Illinois
caught in 1996, representing an increase of nearly 1,222%. All the moth catches were in the northern third of the state as reported by the Illinois Department of Agriculture, APHIS PPQ, and the USDA Forest Service. Caterpillars and pupae were observed in many of the counties. Reports from Indiana indicate high moth numbers in the northwestern counties, with some moths caught as far south as Indianapolis. Gypsy moth will become permanently established probably within 5 years. These populations will build and will cause defoliation.
An oak wilt video was released in March 1995 and still is available through the University of Illinois. The video was produced using grants from the USDA Forest Service, Minnesota Department of Natural Resources, Illinois Dept. of Natural Resources, and the Joyce Foundation. To date, more than 400 copies have been distributed, making it the number one video distributed by the University of Illinois. The color video presents detailed information about the disease, its distribution, hosts, how it's spread, and prevention and control methods. This video is a useful tool for homeowners, arborists, foresters, and other interested people.

This 20 minute video can be purchased by sending a $25 check payable to the University of Illinois to: Agricultural Publications, 67 Mumford Hall, 1301 W.Gregory, Urbana, IL 61801, and request oak wilt OACE #015, or phone Cyndi Moore at 217-333-2007, or FAX 217-344-7503.

Other Issues
The pine shoot beetle continues to extend its range in the State. The first beetles in Illinois were discovered in 2 counties in 1992. In 1997 the number of counties infested is 24. Christmas tree growers are keenly aware of the need to practice good tree sanitation, and promptly dispose of any dead or dying tree, either by converting the wood to mulch or burning it. Pine wind breaks on other properties that are not maintained do pose as a problem to some growers a such sites harbor not only the pine shoot beetle, but weevil and longhorned beetle species as well.

White pine decline, caused by the fungus Leptographium procerum, has been a concern of Christmas tree growers for the past 10 years. Trees may appear to be healthy for 10 years and then during one year there is a noticeable reduction in length of the new growth. Usually the following year, there is little new growth, the needles turn a light green and about one month later the tree is dead. In a few instances, pinewood nematodes have been found in the branch wood, but most samples are negative for the nematode. Ips beetles rapidly invade the tree when symptoms of light green needles are observed.

The Shawnee National Forest sustained an outbreak of the forest tent caterpillar in the Oakwood Bottoms in 1997. More than 2,200 acres of forest had at least 50% defoliation. Egg mass surveys conducted in late summer found the density was below .07 egg masses per branch, indicating defoliation in 1998 should not be significant.

For more information contact:

Stewart Pequignot,
State Forester
600 Grand Ave. West
Springfield, IL 62706
(217) 782-2361
Illinois DNR logo

Forest Health Protection
Northeastern Area
USDA Forest Service
1992 Folwell Avenue
St. Paul, MN 55108
(612) 649-5261

Northeastern Area, S&PF logo

February 1997.......


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