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Agronomic Crops Network

Ohio State University Extension


Black Cutworms and Armyworms Still a Concern

Cutworm damage on corn

Reports of black cutworm and armyworms catches are still coming in from surrounding states. The big concern over the next few weeks will be egg hatch and larval growth. Both hatch and growth is difficult to predict and is largely based on temperature and growing degree days. From the temperature outlook, we should see 3rd or 4th instars of black cutworm by the 2nd or 3rd week of May, weather dependent.

Corn from the V2 to the V6 stage is vulnerable to damage and cutting, and, if much of the planting starts at the end of this week or the beginning of next, we may see some fields with heavy feeding.  For armyworm, we expect to see larvae a bit earlier, perhaps by the 2nd week of May.

Rescue treatments are still a good option for control. However, I failed to mention last week that some transgenic corn varieties will provide control for both pests.  For a list of which varieties have which traits against which insects, you can look at this handy Bt trait table developed by Dr. Chris DiFonzo at Michigan State:

Crop Observation and Recommendation Network

C.O.R.N. Newsletter is a summary of crop observations, related information, and appropriate recommendations for Ohio crop producers and industry. C.O.R.N. Newsletter is produced by the Ohio State University Extension Agronomy Team, state specialists at The Ohio State University and the Ohio Agricultural Research and Development Center (OARDC). C.O.R.N. Newsletter questions are directed to Extension and OARDC state specialists and associates at Ohio State.