During the 1980 growing season a series of standard, single-cup pitfall traps were maintained in wheat, oat, barley, and rye fields in Michigan. The traps were maintained by Pest Management Field Assistants (PMFAs) and entomology students from Michigan State University. The traps were primarily used to monitor insect pest activity as part of pest management scouting.
Dunn, Gary A.
"Ground Beetles (Coleoptera: Carabidae) Collected by Pitfall Trapping in Michigan Small-Grain Fields,"
The Great Lakes Entomologist, vol 15
Available at: https://scholar.valpo.edu/tgle/vol15/iss1/5