No. 17 Article 3/July 18, 2008

With a Few Exceptions, Corn and Soybean Insects Are Relatively Quiet Thus Far

The obvious exception to the otherwise low-key state of affairs regarding corn and soybean insects is Japanese beetles. However, in a July 14 teleconference of extension entomologists in the north-central region, most participants indicated that not much was happening insectwise in most states. Insect pests of interest throughout the Midwest right now are western bean cutworms (initial captures have been reported in all states) and soybean aphids, which are very low in number in most of the eastern Corn Belt and are common but not numerous elsewhere. Marlin Rice, extension entomologist at Iowa State University, shared a report from northeastern Iowa of 3 of 25 plants infested, with 779 aphids on one plant. A large number of aphids on such "starter plants" can represent the beginning of a larger, fieldwide infestation, so vigilance for similar situations is encouraged. Also worthy of note are very large numbers of armyworm moths being captured in traps in some Midwest locations. Several entomologists recalled that numbers of armyworm moths captured during midsummer in 2001 and also in 2007 in some locations also were very large, but little resulted from these large flights. Nonetheless, we will want to be watchful for armyworms feeding on corn leaves.--Kevin Steffey

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