Western bean cutworm.
Western bean cutworm.

Late-harvested corn may be at risk for some growers this year thanks to western bean cutworms that have infested some fields, leaving some damaged crops susceptible to toxin-contaminated mold, said plant and insect experts in the College of Food, Agricultural, and Environmental Sciences at The Ohio State University.

The concern is that in some late-harvested corn fields, western bean cutworm feeding has left some corn crops susceptible to fungi such as Fusarium, Gibberella and Aspergillus that produce mycotoxins that can be harmful to animals and humans if used in corn for grain and human food consumption, said Pierce Paul, an Ohio State University Extension corn and small grain specialist.

The holes and damage caused by the western bean cutworm feeding could lead to secondary infestations from mold and fungi that could lead to toxin-contaminated grains, said Paul, who is also a plant pathologist with the Ohio Agricultural Research and Development Center. 

OSU Extension and OARDC are the outreach and research arms, respectively, of the college. 

“The important thing for growers to do at this point is to check their crops for damage caused by insect feeding,” he said. “Those damaged crops should then be checked for mold growth.

“Fields found infected with mold growth should be harvested separately from non-infected fields.”

However, just because the grain has mold, doesn’t mean that it is associated with mycotoxin contamination, Paul cautioned.

“Some of the damaged kernels may be colonized by opportunistic molds,” he said. “Therefore, samples from the infected grains should be sent to an approved laboratory to determine whether vomitoxin or other toxins are present and whether they exceed thresholds established by the U.S. Food and Drug Administration.

“Until you know for sure, it’s best to avoid feeding moldy grains to livestock.”

Growers who find that they must use moldy grain should be sure that it doesn’t exceed the recommended limit for the detected toxin based on what animal is being fed, Paul said.

More information on mycotoxin testing is available at go.osu.edu/graintest.