We have concluded our third week of monitoring for black cutworm (BCW) and true armyworm (AMW)! Monitoring traps took place between April 27th – May 3rd. While many counties saw a lot of rain over the past week, the temperatures are slowly ticking up, and with that, so are our numbers!
Black cutworm
Over the past week BCW moth had a range of averages from 0 to 45.0 moths. Overall, we monitored a total of 46 traps in 19 counties. Our statewide average continues to increase and is now 10.6 moths (up from an average of 8.8 moths the previous week). Counties that had averages of 7.0 moths or more are over our threshold level and encouraged to scout your fields in the next two weeks. These counties included Auglaize, Defiance, Fayette, Fulton, Hardin, Henry, Lucas, Madison, Van Wert, and Wood (Figure 1).
Black cutworm moths are dark brown to black with a small black dagger mark two-thirds of the way toward the outer edge of the wing (Figure 2). Moths lay eggs, which hatch in 5 – 10 days. Once hatched 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 (such as chickweed and purple dead nettle). 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 3: April 27th to May 3rd, 2026
Figure 1. Black cutworm (BCW) moths captured from April 27th to May 3rd. The bold number indicates the average moth count for the week, followed by the total number of traps in that county.
Figure 2. Black cutworm moth. Photograph by Robert J. Bauernfeind, Kansas State University
True Armyworm
True armyworm was also monitored last week with 43 traps in 18 counties (Figure 3). The statewide average for the week also increased to 21.5 (up from an average of 9.8 moths the previous week). Most of the moth activity we are seeing is in northwest Ohio. Counties with averages higher than 7.0 moths include: Fulton, Henry, Lucas, Madison, Putnam, Trumbull, Van Wert, and Wood. Again, we suggest that counties with a weekly average of 7.0 moths scout for AMW larvae in the coming weeks. This week, Lucas and Van Wert had averages higher than 7.0.
Adult AMW are tan to reddish brown and have a single white mark in the center of their wing (Figure 4). Adults lay eggs in grasses and rye cover crops. The eggs hatch and the feed on young corn plants. Counties with high trap numbers should monitor for AMW larvae after corn is planted, especially in areas of grassy no-till fields or fields that had rye cover crop.
True Armyworm Moth Map
Week 3: April 27th to May 3rd, 2026
Figure 3. True armyworm moths captured from April 27th to May 3rd. The bold number indicates the average moth count for the week, followed by the total number of traps in that county.
Figure 4. True armyworm moth. Photograph by John Capinera, University of Florida.