Pictured: Western bean cutworm trap. Photo by Canadian Corn Pest Coalition
Western bean cutworm moth counts registered during the June to mid-August flight period increased for the fourth consecutive year to set a 20-year survey record.
Each growing season, DATCP Pest Survey field specialists survey alfalfa, corn, soybeans, and small grains across the state to collect data on the leading economic pests of concern to Wisconsin crop producers. In DATCP’s end-of-season wrap of the surveys, western bean cutworm moth counts were the furthest from normal.
The 2024 trapping program captured an average of 227 moths per trap (15,685 moths in 69 traps), surpassing the previous record of 222 moths per trap (9,351 moths in 42 traps) set in 2023, and nearly quadrupling the 20-year average of 57 moths per trap. The highest individual trap catch for the 11-week survey period was 1,834 moths at Crivitz in Marinette County, while one-third of the sites recorded cumulative counts above 250 moths per trap.
This season’s extensive network of 69 traps in 30 counties helped identify high moth count areas in the western and northeastern regions of the state, beyond the traditional WBCW high-pressure zone in central Wisconsin.
Fall surveys found corresponding hot spots in Buffalo, Jackson, Sauk, and Trempealeau counties. Overall, western bean cutworm caterpillars were in ear tips in 8 percent of the 229 corn fields sampled in September and early October.
