Trapping Update
Between April 20 and April 26, 19 trap sites reported a total of 96 black cutworm moths captured in traps (Figure 1). There were five significant flights during the week (Figure 2), including Buena Vista, Cerro Gordo, and Franklin counties on April 22, and Marshall and Tama counties on April 24.
Using historical temperature data from the Midwest Regional Climate Center database, Table 1 shows the current projected cutting dates in counties that have had a significant flight. Actual spring temperatures will change these projections, so stay tuned to weekly updates! Remember that it is recommended to begin scouting well before these predicted dates to find larvae before they cut plants.
| County (Crop Reporting District) | Significant Flight Date (Biofix) | Projected Cutting Date |
|---|---|---|
| Tama (Central) | April 12 | May 9 |
| Jackson (East Central) | April 12 | May 8 |
| Polk (Central) | April 13 | May 9 |
| Buena Vista (Northwest) | April 22 | May 22 |
| Cerro Gordo (North Central) | April 22 | May 22 |
| Franklin (North Central) | April 22 | May 22 |
| Marshall (Central) | April 24 | May 22 |
| Tama (Central) | April 24 | May 22 |
Although no significant flights have been reported in southern Iowa yet, it is worth noting that scouting should begin even earlier in southern counties since temperatures are warmer and more degree days have likely accumulated.
More Information
For more information on black cutworm identification, injury, and management options, read the black cutworm encyclopedia article. You can find previous weekly reports on the ICM Blog.
Surrounding states also monitor and report black cutworm captures, as well as other moth species. If you live near the state border, it may be beneficial to check these resources periodically. More resources may be available than those 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 April 29, 2026. The information contained within may not be the most current and accurate depending on when it is accessed.
- Extension Specialist II