Lep Monitoring Network Update #4 – Black Cutworm and True Armyworm Numbers Remain High

We have concluded our fourth week of monitoring for black cutworm (BCW) and true armyworm (AMW)! A reminder to all of our monitors, all traps that have lures that have been in since mid-April should have been changed by now (they last about 5 weeks in the field). In this weeks newletter arcticle we are reporting findings from May 4^th through May 10^th. This past week the weather has continued to be a mix of rainy days and some nice warm days mixed in and the insects are remain out and about in abundance.

Black cutworm

Over the past week we monitored a total of 48 traps in 17 counties and saw a slight decrease in our statewide average, which is now at 9.8 moths (down from 10.6 moths the previous week). This indicates we may be past our peak BCW flight in some counties – but moths are still out and laying eggs so make sure you are monitoring into mid-June for this pest. 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 Allen, Auglaize, Defiance, Fulton, Henry, Lucas, Putnam, Van Wert and Wood (Figure 1).

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 4^th to May 10^th, 2026

Figure 1. Black cutworm (BCW) moths captured from May 4^th to May 10^th. The bold number indicates the average moth count for the week, followed by the total number of traps in that county.

True Armyworm

True armyworm was also monitored last week with 43 traps in 16 counties (Figure 2). The statewide average for the week also remains high, but overall decreased to 18.3 moths (down from 21.5 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, Hardin, Henry, Lucas, Putnam, 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.

True Armyworm Moth Map

Week 4: May 4^th to May 10^th, 2026

Figure 2. True armyworm moths captured from May 4^th to May 10^th. The bold number indicates the average moth count for the week, followed by the total number of traps in that county.