Brian Denning sees a lot of corn. He's an area agronomist who writes a newsletter for Stewart Seeds, Greensburg. He covers an area as big as southern Indiana, southern Illinois and parts of Kentucky. Recently, he noted corn earworm and fall armyworm were beginning to show up in ears in fields susceptible to the pests.
Some GMO hybrids are resistant to these pests. Others aren't resistant. Non-GMO corn would all be susceptible. He's relayed word that in some fields these insects are already becoming an issue. Part of the problem is after the insect invades, the ears are set up for secondary disease infections. These include various molds that can do as much or more damage to grain quality as the insects themselves.
It will be a good year to scout for these types of problems, especially in fields that are susceptible and that were stressed, he believes. There was a large amount of earworm and armwyworm moths in flight that coincides with the period later when larvae began appearing in the ears in various areas.
It's also a good year to compare different technologies in the field, he notes. That might best be done in a plot. Hybrids that have Bt protection form an even that doesn't control corn earworm, for example, may be free of corn borer, but could still have earworm attacking.
Some of the newer technology coming onto the market or already on the market has resistance to this pest. Earworm and armyworm weren't the first pests targeted by developers of Bt traits because year in and year out, they don't do as much damage over as wide an area of the Corn Belt as other pests, including European Corn Borer and rootworm. However, in isolated situations like this year, the damage can be significant. And it can also be significant in fields where the pests invade.If you haven't looked at your fields, it might be a good time to take a closer look, he advises. About all you may be able to do know, other than to make notes on hybrids for next year, may be to mark fields that are infested with insects and/or molds for early harvest. It may pay to harvest those fields at higher moisture contents and dry them rather than risk further deterioration in grain quality and yield if left standing in the field.