Dr. Nick Seiter, Research Assistant Professor and Field Crops Entomologist at University of Illinois Urbana-Champaign, and his team will be conducting dectes stem borer counts in fields around Illinois again this fall as part of an ongoing investigation into soybean stem pests funded by Illinois Soybean Association. The sampling will begin in late September/early October around R7-R8 growth stages in soybeans. Additionally, they will conduct counts in stubble post-harvest for dectes larvae that made it to the base of the stem and could successfully overwinter. Dr. Seiter’s group welcomes farmers and ag professionals who are in the field to conduct counts and contribute to the survey.

If you are interested in participating in the dectes stem borer counts, download the protocol here. Send your completed survey sheets to Ashley Decker at alvance@illinois.edu and put “Illinois Dectes Survey” in the subject line of your email. You may print off the sheet to fill it out and send back a scanned copy or send your results in an Excel file. On the protocol sheet, there are lines for both the GPS coordinates and the county of the field where the survey was conducted. If you do not wish to disclose the GPS coordinates of the field, listing the county name only is sufficient.

Dectes stem borer typically does not impact the development of soybeans but can contribute to lodging issues that impact harvest. This survey will help researchers understand the reach of dectes stem borer in Illinois and provide management recommendations to growers in impacted regions.

Read about the 2022 dectes stem borer survey conducted by Dr. Seiter’s lab by clicking here. 

Dectes stem borer larva within a soybean stem; note tunnel lined with brown frass (Photo: Scott Stewart, University of Tennessee)