Our fourth week of monitoring for black cutworm and true armyworm resulted in a slight decline in the statewide average for both pests; however, some counties continue to have high trap numbers. These numbers indicate that both BCW and AMW moths are active in Ohio and may still be laying eggs.
Black cutworm
The statewide average decreased slightly 5.1 during the week ending May 5th to 4.2 for the week ending May 12th. Counties with high averages included Defiance (9.8), Hardin (8.7) and Van Wert (8.6) (Figure 1). Adult moths lay eggs that hatch in 5 – 10 days. The larvae go through 6 instar stages over the next 28 – 35 days. Counties with high trap numbers should plan to scout for BCW larvae after corn is planted until V6 stage, especially in fields with a lot of broadleaf weeds. For more information on how to scout BCW please visit: https://aginsects.osu.edu/sites/aginsects/files/imce/ENT_35_14 BCW.pdf
Black cutworm moth map - Week 4
May 6th to May 12th, 2024
Figure 1. Average black cutworm (BCW) moths captured from May 6th to 12th. 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 traps set up in that county.
True Armyworm
Following a similar trend to BCW, the statewide average decreased for AMW from 9.4 moths for the week ending May 5th to 8.0 for the week ending May 12th. Counties with the highest averages included Van Wert (18.3), Henry (12.0) and Defiance (9.5) (Figure 2). Plan to scout fields after corn is planted in counties that have had high averages, especially in fields that were previously planted to cover crops.
True Armyworm moth map - Week 4
May 6th to May 12th, 2024
Figure 2. Average true armyworm (AMW) moths captured from May 6th to May 12th. 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 traps set up in that county.