Degree days are a useful tool to estimate when common stalk borer larvae begin moving into cornfields. Start scouting corn for larvae when 1,300-1,400 degree days (base 41°F) have accumulated. Temperatures have been variable this spring and degree days have been slowly increasing. Southeastern Iowa reached this important temperature benchmark this week (Fig. 1) and therefore scouting for migrating larvae in corn should begin now to make timely treatment decisions. Consider applications at peak larval movement, or 1,400-1,700 degree days (base 41°F).
Iowa State University
Hodgson, Erin W. and Sisson, Adam, "Stalk Borers Begin Migration to Corn" (2015). Integrated Crop Management News. 331.
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 Users are hereby notified that the content may be inaccurate, out of date, incomplete and/or may not meet the needs and requirements of the user.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/.