Pictured: Western bean cutworm moth. Photo by OSU.edu
Preliminary results of the 20th annual western bean cutworm trapping survey show a cumulative state count of 11,871 moths in 69 traps, or an average of 172 per trap. This is according to the Department of Agriculture, Trade, and Consumer Protection.
This season’s current average moth catch is below last year’s all-time record high capture of 223 moths per trap (9,351 moths in 42 traps), although there are still three more weeks of monitoring left and the flight has not yet peaked in parts of northern Wisconsin.
Peak activity should occur Aug. 2-8 in areas north of Wausau, as western bean cutworm growing degree day accumulations reach 2,704. The modified base 38°F column in DATCP’s degree day table shows Wausau has accumulated 2,677 gdds as of July 31, Medford has 2,631 gdds, and Crandon is at 2,451 gdds: https://datcp.wi.gov/Pages/Programs_Services/DegreeDays.aspx
For the week ending Aug. 1, the total catch was 4,660 moths, an increase from 3,658 moths July 19-25. This week’s high individual trap count was 367 moths near Taylor in Jackson County, while seven monitoring locations reported catches above 200 moths per trap.
DATCP expects counts across southern and central Wisconsin to drop off sharply next week as the flight subsides. Western bean cutworm trapping network participants should continue reporting counts through Aug. 22.
