2024 Iowa Moth Trapping Network Update: Week 8

Moth flights into Iowa were drastically reduced during Week 8 (May 19 to May 25), partly because of fewer moths but also likely due to the fact that recent storms took out several traps across the state. Our cooperators recorded only 51 black cutworm (BCW) moths and, for the first time since Week 1, no significant flights were recorded.

Figure 1 shows where moth traps are established throughout Iowa and black cutworm trap captures by county. Figure 2 shows the maximum 2-night capture in each county. This is an important distinction because although total moth counts tell us a bit about moth activity in the region, we determine whether a significant flight has occurred based on total captures over two nights. The red coloration on both maps indicate significant flights occurred, but Figure 2 gives a better sense of where large flights occurred even if they were not significant.

Since BCW moths are still arriving in Iowa, plan to scout corn until the V5 growth stage. Look for missing or cut plants, and refer to this encyclopedia article to help make management decisions. First cutting dates have already been posted, but continued flights into Iowa could mean a prolonged risk of black cutworm to seedling corn.

Follow the links to see reports from Week 1, Week 2, Week 3, Week 4, Week 5, Week 6, and Week 7. You can also track moth flights, black cutworm significant flights, and projected cutting dates for Iowa, Illinois, and Wisconsin at https://corn.ipmpipe.org/insects/.

Surrounding states also monitor and report BCW and TAW 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:

• University of Minnesota
• University of Missouri
• University of Illinois
• University of Nebraska-Lincoln