Integrated Crop Management is published by the Department of Entomology , Iowa State University , Ames, Iowa. Grasshopper populations are abundant in some soybean fields this summer. Red-legged grasshoppers are common in soybeans.
Reports indicate that half-inch grasshoppers are abundant in many ditches, fencerows and waterways.
Paul Kassel, extension field specialist in crops at Spencer, reports that border rows in some soybean fields are heavily defoliated. Only nymphs have been found so far. Grasshopper nymphs defoliating soybean leaves. There are no good economic thresholds to use in either corn or soybeans. Old thresholds recommended counting the number of grasshoppers per square yard, but I do not like this method.