The insect "highlights" of 2001 included more problems with soil insect pests in corn (especially white grubs), a historic outbreak of armyworms, variegated cutworm problems in soybeans, corn rootworm control problems, unusual behavior of corn rootworm adults, infestations of twospotted spider mites and soybean aphids, continuing problems with southwestern corn borers in southern counties, and higher numbers of second-generation European corn borers in many areas of the state. It's a fair bet that some of these problems will reoccur in 2002. However, some of these insects (e.g., armyworm and variegated) most likely will be relegated to our memory chip for 2001.|
We anticipate potentially significant problems with corn rootworms in 2002. The numbers of adults in many areas of the state were extremely large, so we suspect that the beetles laid lots of eggs. Producers who farm just beyond the 32-county area affected by the "strain" of western corn rootworms that lay eggs in soybean fields should be particularly vigilant in 2002. The problem with the new "strain" of western corn rootworms has been verified in the following counties: Champaign, Christian, Coles, DeKalb, DeWitt, Douglas, Edgar, Ford, Grundy, Iroquois, Kane, Kankakee, Kendall, LaSalle, Lee, Livingston, Logan, Macon, Marshall, McLean, Moultrie, Ogle, Peoria, Piatt, Putnam, Sangamon, Shelby, Tazewell, Vermilion, Warren, Will, and Woodford. Obviously not all fields in all of these counties are infested with corn rootworms. Nevertheless, keen observation during any given year is paramount if producers hope to avoid significant yield losses the following year.
Management options for corn rootworms have expanded to include granular and liquid insecticides and insecticidal seed treatments. We have addressed the relative effectiveness of these products in several past issues of the Bulletin. We also invite you to check out the Web sites of other states' newsletters for efficacy data. The more data you study, the more informed you will be about the level of root protection you can expect from any given product. If rootworm populations are large in 2002, as we expect, the rootworm-control products will be challenged.
We also can anticipate more first-generation European corn borers in 2002 than we have experienced in recent years. Although the numbers of larvae we find during our fall surveys do not always foretell the next year's levels of infestations, larger numbers generally elevate our level of alertness. Depending upon the winter weather and, more importantly, the weather next spring, first-generation European corn borers could attract our attention.
We have little reason to doubt that some of the secondary insect pests of corn will continue to wreak havoc in some areas. Try to gather as much information as you can about the potential for white grub and wireworm problems, and be prepared to recommend or use control measures (insecticides or insecticidal seed treatments) if either pest poses a threat. Remember, differences in infestations of white grubs and wireworms vary significantly from field to field, so field-specific information is extremely important.
Finally, a lot more data-gathering related to soybean aphids occurred in 2001. During the winter months we will accumulate data and observations from our colleagues in the states where soybean aphids have caused significant problemsprimarily Michigan, Minnesota, and Wisconsin. We also will summarize what our research teams have learned in Illinois. From this information we will draw up a "battle plan" in preparation for the return of soybean aphids in 2002.
In addition to these by-now-familiar insect pests, we probably will have to deal with others that we cannot anticipate right now. So, be preparedlearn and plan to implement appropriate strategies as needed.--Kevin Steffey