Ohio State Entomologist: Begin Scouting for Spring Pests at Planting Time

WOOSTER, Ohio – A migrating moth that can cause significant stand loss in corn is just one of the pests growers should be on the lookout for as they gear up for spring planting, an entomologist with Ohio State University’s College of Food, Agricultural, and Environmental Sciences said.

Black cutworms have been reported in the neighboring states of Indiana and Pennsylvania in significant numbers in traps set up by entomologists to determine the number of moths migrating up from the south, said Andy Michel, an Ohio State University Extension pest expert.

That means Ohio growers should be prepared to begin scouting their fields for this insect, he said.

The pest, while not a widespread problem throughout Ohio, tends to prefer to infest fields with significant ground cover and weed presence, said Michel, who also has an appointment with the Ohio Agricultural Research and Development Center.

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

“It’s hard to predict where an infestation may occur (because) black cutworm is a migratory moth and wherever they land, they land,” he said. “With black cutworm, growers can find significant injury especially after planting, right when the corn is starting to emerge.

“If you do have an infestation, you could have some significant stand loss, with areas that may need replanting or rescue treatments.”

The concern for this pest is that the migrating moth lays eggs in cornfields, which can cause severe cutting of the plant, Michel said. The resulting stand loss in corn is generally associated with below- or at-ground level feeding injury, which occurs below the growing point, he said.

Growers who find black cutworm infestations may find that while preventative treatment, including insecticidal seed treatment, is not as effective, rescue treatments are, Michel said.

“But the best management tool for growers is to scout for cutting after corn emergence,” he said.

More information on black cutworm can be found in an OSU Extension fact sheet at http://ohioline.osu.edu/ent-fact/pdf/0035.pdf.

Another pest growers can look out for is the seedcorn maggot, which can impact both corn and soybeans, Michel said. This pest also tends to be found in fields with heavy organic matter or recently tilled-under alfalfa, hay or wheat fields.

Growers who find seedcorn maggots can control the pests with insecticidal seed treatments or commercially applied insecticide seed treatments, he said.

Lastly, growers who find seedcorn maggots in their fields can delay planting by three to four weeks in a field that has green cover tilled under, Michel said. That should be plenty of time for seedcorn maggots to have finished their larval stage, which would limit damage, he said.