No. 17 Article 5/July 21, 2006

Insect (and Mite) Coming Attractions?

Based on the reports we have received, as well as input from other entomologists in the Midwest, a few insects and mites require some vigilance in the weeks to come. Following are comments that hopefully will serve as reminders.

In corn, much of the focus now and in the recent past has been on corn rootworms (both larval damage and large numbers of adults) and Japanese beetles. However, we have heard rumors of larger-than-usual infestations of European corn borers in some areas. This is a relative statement based on the virtual lack of infestations in recent years, but the statement deserves attention. If infestations of European corn borers are more common in 2006, our annual fall survey should be reflective. In the meantime, let us know what you find.

Since 2001, the primary insect of concern in soybean has been the soybean aphid, which still garners the bulk of attention. However, we need only to think back to 2005 to remember the impact of twopotted spider mites on soybean in drought-stricken areas. Some areas of Illinois are still dry, so the high temperatures and lack of moisture will favor the buildup of spider mite populations. Keep your eyes open. Also, the report of woollybear caterpillars in corn, albeit from only one field, suggests that we should watch for woollybears in soybean fields as the plants enter reproductive stages of growth. In dry areas, a fungal disease that often suppresses woollybears may not be there to keep the pests' numbers down. And while you're watching for soybean aphids, twospotted spider mites, and woollybear caterpillars, look for bean leaf beetles and green stink bugs, too. Both of these insects can cause significant losses if their densities are large when pods and seeds are forming and filling, and both will be present in soybean fields well into August. Although some of the scouting efforts in corn will diminish after pollination, scouting in soybean fields should continue.--Kevin Steffey

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