To receive weekly email notification when the latest issue of the Bulletin is online, click on this link and fill out the form.

No. 16/July 10, 2003

Click here to download the print-ready PDF of this week's issue.
Note: To view PDF files, you need the free Adobe Acrobat Reader.

Japanese Beetles Are a Widespread Concern in Illinois
Japanese beetles have become established in most of Illinois in recent years. It is easy to overreact to their attention-getting presence; be sure after scouting to make a decision that seems economically justifiable. Suggested products are listed for cases where insecticidal control is warranted.

Numbers of Soybean Aphids Keep Increasing
There is no sign of slowdown in the increase of soybean aphids in northern Illinois. Remember that some of the symptoms of this pest's injury can be confused with other problems. Insecticide applications to prevent yield losses are recommended only during late vegetative and early reproductive stages of soybean growth.

Emerging Insect Issues
Observations and recommendations on corn rootworm, grasshoppers, and fall armyworm are presented.

Odd-Looking Field Corn Diseases
Leaf blights are likely to take advantage of the current high moisture and humidity. Common smut and crazy top are two diseases that may be observed as the corn begins to tassel.

Gray Leaf Spot in Illinois Cornfields
The severity and incidence of gray leaf spot and other corn leaf diseases will be affected by July's rainfall, humidity, and temperatures. Now is the time to consider scouting. Development of gray leaf spot is reviewed and management options are discussed.

University of Illinois Weed Science Web Site
The U of I Weed Science Web site is now live at, with numerous topics and links regarding weed management.

Looking at Crops in Midseason
Symptoms of nitrogen deficiency in fields that seem otherwise in excellent condition are puzzling. K deficiency may be the most visible result, rather than the cause, of a restricted root system. Overall, the corn crop looks good to outstanding in most early-planted fields. Growing conditions have resulted in somewhat delayed tassel appearance in corn and flowering in soybean. Yield potential still appears high for the soybean crop.

Regional Reports
Reports are provided this issue for northern, southern, and west-central Illinois.

The Pest Management and Crop Development Bulletin
Executive Editor: Kevin Steffey, Extension Entomologist

Subscription information: Phone (217) 244-5166 or email
For comments or questions regarding this web site contact: Michael Greifenkamp