Source: Ohio State University
A substantial increase in western bean cutworm catches has been observed in Ohio, according to Ohio State University. The total for 2010 so far is 47. Last year, only 47 were caught by July 13, so moths are being seen much earlier this year. A couple of observations suggest that some of these moths may be coming from states to the west.
Although much of the state is a little behind the pre-tassel stage, some fields in southern and west-central Ohio have begun to tassel. This is important because multiple moths are being caught in these areas.
To scout for eggs, inspect a minimum of 20 plants at five locations in your field. Eggs are normally laid on the upper surface of the top most leaves. Eggs are laid in masses of 20-100, and are first white in color. After a few days, they turn tan, and then turn a deep purple. Egg stage lasts about a week, but once eggs turn purple, larvae will emerge within 48 hours. If 5 percent or more of corn have egg masses, treatment is necessary once larvae have emerged — western bean cutworms are protected against treatment in the egg stage.