Moth Trapping Network 2025 Update 6

Content Author: Rebecca Vittetoe

The week of May 18 – May 14, 2025 saw minimal moth activity for both black cutworms and true armyworms across the state.

A total of 10 black cutworm (BCW) moths were reported last week, with no significant flights. As a reminder, now is the time to be scouting for black cutworm based on our predicted cutting dates from previous significant flights from earlier this spring combined with growing degree days.

Figure 1 below shows where moth traps are established throughout Iowa and summarizes black cutworm moth trap captures by county. 

Black cutworm moth counts across Iowa from May 18 - May 24, 2025
Figure 1. Black cutworm moth captures from May 18 – May 24, 2025. The bigger and bolded number indicates the total moth count for the week (for counties with multiple sites, only the site with the highest weekly moth count is reported. The smaller number in parenthesis represents the season-long total black cutworm captures in that county. Data is current as of May 24, 2025.  

 


For true armyworms, there were no moths caught last week with our trapping network, as indicated in figure 2 below.

No true armyworm moths were caught in our trapping network from May 18 - May 24, 2025.
nnnFigure 2. True armyworm moth captures from May 18 – May 24, 2025. The bigger and bolded number indicates the total moth count for the week (for counties with multiple sites, only the site with the highest weekly moth count is reported. The smaller number in parenthesis represents the season-long total black cutworm captures in that county. Data is current as of May 24, 2025. 


 


Follow these links to see the firstsecondthird, fourth, and fifth moth trapping network updates for 2025. This next week will be our last week for monitoring for black cutworm and true armyworm moth activity for 2025. 

You can also track moth flights, black cutworm significant flights, and projected cutting dates for Iowa, Illinois, and Wisconsin on https://corn.ipmpipe.org/insects/. Iowa’s data is now included on this website! 

Surrounding states also monitor and report black cutworm and true armyworm captures. If you live near the state border, it may be beneficial to check these resources periodically. More resources may be available than what is listed here:

Links to this article are strongly encouraged, and this article may be republished without further permission if published as written and if credit is given to the author, Integrated Crop Management News, and Iowa State University Extension and Outreach. If this article is to be used in any other manner, permission from the author is required. This article was originally published on May 26, 2025. The information contained within may not be the most current and accurate depending on when it is accessed.