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
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.
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
|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.
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.
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:
600 Grand Ave.
Springfield, IL 62706
Forest Health Protection
1992 Folwell Avenue
St. Paul, MN 55108