Grasshopper nymphs were found in central Iowa during late May and they now have reached a size where they are getting the attention of crop scouts. No economic injury has been reported, but their appearance in weedy areas and field edges should serve as an early warning of potential crop damage. There are no good economic thresholds for grasshoppers in either soybean or corn. Old thresholds recommended that you count the number of grasshoppers per square yard, but I have always found this method frustrating.
Iowa State University
Rice, Marlin E., "Grasshoppers are here, but no damage yet" (2001). Integrated Crop Management News. 1924.
The Iowa State University Digital Repository provides access to Integrated Crop Management News for historical purposes only. Users are hereby notified that the content may be inaccurate, out of date, incomplete and/or may not meet the needs and requirements of the user. Users should make their own assessment of the information and whether it is suitable for their intended purpose. For current information on integrated crop management from Iowa State University Extension and Outreach, please visit https://crops.extension.iastate.edu/.