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Agronomic Crops Network

Ohio State University Extension


Insect Concerns for Late Planting

cereal leaf beetle feeding in wheat

With much of the state still yet to plant, growers should be keep a few insect pests in mind as they get in into fields this week:

Wheat: The two most important insects in wheat right now are armyworms and cereal leaf beetle.  Armyworms are difficult to predict, although the trap data from the University of Kentucky suggests that we may not be in an outbreak year. Nonetheless, it would be good to scout for these striped caterpillars in wheat fields, as well as any cover crops that may have corn planted this week.  Adult cereal leaf beetles have just started to be seen, so we would expect larvae to begin feeding soon.  We have increasing problems with this pest, so growers should watch out for these small, black larvae that look like “bird droppings.”  More information on cereal leaf beetles and armyworm at  and

Corn: Reports of high numbers of black cutworm in traps across the Midwest suggests that it may be in a few fields.  As these larvae develop, they will be hungry and willing to feed on emerging corn. While there are some Bt-corn varieties that offer some protection, rescue treatments work very well.  Over the next few weeks during corn emergence we recommend to keep an eye out for any corn with leaf feeding or stem cutting.  Growers in southern OH may see feeding this week.  We have also seen Asiatic garden beetles rearing their ugly heads again in northwest Ohio (see scouting video at: ). Unfortunately, control is difficult with this pests—the good news is that we have historically seen less pressure with later planting.  Please keep us informed of this pest, as we are continually doing research to find new solutions for its control. 

Soybean: As much soybean hasn’t been planted, there isn’t much of a concern for insects. However, those fields that were planted may be at risk for bean leaf beetle feeding—especially if there are very few other soybean fields planted. More information at

Slugs: With the rain and cool weather, we may be entering a period of heavy slug feeding.  As corn emerges, these young slugs will also be hungry and feed on corn and soybean.  No-till fields with high residue are at particular risk.  During emergence, fields should be inspected for slugs, especially in fields with a history of slug damage.  The two available baits are those containing metaldehyde (Deadline MPs and others), and those with iron phosphate (Sluggo). More information can be found in our fact sheet at:   

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.