Farmers Needed for Second Year of Soil Pest Research in Corn and Soybean in Southern Minnesota

Drs. Fei Yang, Extension corn entomologist, and Bob Koch, Extension soybean entomologist, are continuing a project to evaluate pests that feed on seeds and seedlings in corn and soybean fields in southern Minnesota. In areas with severe infestations, these pests can cause significant stand losses or even require replanting of fields. Despite these potential impacts, much remains unknown about these pests in Minnesota corn and soybean. This article serves as a request for additional cooperating farmers for 2025, and an update on results from 2024.

Request for cooperating farmers for 2025

They are seeking cooperating farmers in southern Minnesota to allow their research team to sample corn and soybean fields from April to June 2025.

They are especially interested in sampling corn and soybean fields with the following characteristics:

• have recently come out of pasture, CRP, etc.,
• are no-till,
• are following cover crops,
• have high organic matter, and/or
• have not had insecticide seed treatments used in recent years.

However, the sampling will not be limited to fields with those characteristics.

Farmers with fields selected for sampling will receive a free report on the pests encountered in their fields.

Please fill out this short form by March 31, 2025 if you are interested in allowing their research team to sample your field.

Fill out the form

If you have questions, contact:
Hunter Ness (graduate student in Entomology), nessx205@umn.edu or 612-289-3475.

Update on 2024 results

We conducted soil insect surveys in 24 corn and soybean fields across southern Minnesota. These surveys consisted of two parts:

• Dig out 1 cubic foot of soil from 5 or 7 locations in each field, and sift through for wireworms and white grubs.
• Deploy 10 “baits” per field. Baits consisted of a ball of germinating corn and wheat buried 6 inches below ground. Baits were collected 2 weeks later and brought back to the laboratory to detect any wireworms or white grubs.

Overall results

Soil pest pressure was low in all of the fields we surveyed. White grubs were found in 7 fields and wireworms were found in 6 fields. All fields sampled showed pest pressure below the economic thresholds of 2 white grubs or 1 wireworm per soil sample or per trap.