After rounding out our sixth week of monitoring for black cutworm and true armyworm, the slight decline that was seen over the past two weeks in the statewide average for both pests has continued to drop. Hardin county recorded the highest average of BCW pests last week, while Van Wert has continued to see the highest average of AMW pests this past week. These low averages indicate that we are nearing the end of the season for both BCW and AMW moths in Ohio.
Black Cutworm
The statewide average for BCW pests decreased from 2.7 during the week ending on May 19th to 1.3 for the week ending May 26th. Counties with the highest averages included Hardin (4.0), Brown (3.5) and Clinton (3.0) (Figure 2). When scouting for BCW larvae, fields with broadleaf weeds, specifically chickweed, should be more closely monitored from after the time corn is planted until it reaches the V6 stage. Counties with high trap numbers throughout the season should pay close attention to and plan to scout for BCW larvae. See below (Figure 1) for what to look for when scouting. For more information on how to scout BCW please visit: https://aginsects.osu.edu/sites/aginsects/files/imce/ENT_35_14 BCW.pdf
Figure 1. Black cutworm on hand. Photo Credit: Amy Raudenbush, The Ohio State University CFAES
Black cutworm moth map
Week 6: May 20th to May 26th, 2024
Figure 2. Average black cutworm (BCW) moths captured from May 19th to 26th. The bold number on the left indicates the average moth count for the week, followed by the standard number on the right which indicates the total number of active traps set up in that county.
True Armyworm
Similar to the trend we have been seeing, the statewide average for AMW again decreased from 2.1 moths for the week ending May 19th to 1.5 for the week ending May 26th. Counties with the highest averages this week included Van Wert (3.1), Henry (3.0) and Muskingum (3.0) (Figure 3). As previously mentioned, be sure to scout fields after corn is planted in counties that have had high averages thus far, especially in fields that were previously planted to cover crops.
True Armyworm moth map
Week 6: May 20th to May 26th, 2024
Figure 3. Average true armyworm (AMW) moths captured from May 19th to May 26th. The bold number on the left indicates the average moth count for the week, followed by the standard number on the right which indicates the total number of active traps set up in that county.
Start Scouting for Corn Earworm
As we are closing out of our season for black cutworm and true armyworm pests in Ohio, it is important to be prepared and ready for our next seasonal pest coming. We only have two more weeks reporting on BCW and AMW pests but will be switching to reporting on corn earworm (CEW) very soon (Figure 4). To learn more about corn earworms, check out one of our previous newsletters: https://agcrops.osu.edu/newsletter/corn-newsletter/2019-27/corn-earworm-field-corn-watch-molds
Figure 4. Corn earworm feeding on an ear of corn. Photo Credit: Robert J. Bauernfeind, Kansas State University, Bugwood.org