The 2024 moth trapping season is underway, and our volunteers began placing traps the week of March 24. Black cutworm (BCW) monitoring is a long-standing project in Iowa to detect moths migrating from southern overwintering sites each spring. By monitoring adult black cutworms, we can provide scouting recommendations to growers to avoid significant injury from black cutworm larvae.
Iowa State University’s IPM Team has monitored field crop pests for a long time. The pests have changed over the years, but the goal is the same: to help inform farmers about pest activity in Iowa. Our moth trapping efforts target black cutworm, which is a migratory moth. Since timing of arrival is variable between growing seasons, trapping black cutworm helps us predict when injury will occur.
The trapping season for true armyworm (TAW) and black cutworm (BCW) has come to an end. We appreciate our cooperators for tirelessly checking traps the last two months and reporting their captures so we can provide the most accurate scouting information for these pests. To recap, we had 31 volunteers participate from 26 counties in Iowa. A total of 34 BCW and 34 TAW traps were placed and monitored during April and May.
Moth flights into Iowa slowed down a bit during Week 7 (May 14 to May 20). Cooperators for the Iowa Moth Trapping Network reported 147 black cutworm (BCW) and 130 true armyworm (TAW) moths, with three new significant flights of black cutworm. More details on significant flights and cutting dates can be found in the resources below:
Week 6 (May 7 to May 13) of the Iowa Moth Trapping Network was vastly different than the week before. Our cooperators reported 239 black cutworm (BCW) and 295 true armyworm (TAW) moths, with several significant flights occurring around the state.
Very few moths were reported by our cooperators last week. During week 5 of the Iowa Moth Trapping Network (April 30 to May 6), our cooperators reported 41 black cutworm (BCW) and 32 true armyworm (TAW) moths around the state, and there were no new significant flights of BCW to report. However, based on significant flights that occurred during April, we were able to predict initial cutting dates for BCW using accumulated and forecasted growing degree days.
Fewer moths were reported last week than in previous weeks, but even so, the northward migration of two pest species continues. During week 4 of the Iowa Moth Trapping Network (April 23 to April 29), our cooperators reported 71 black cutworm (BCW) and 85 true armyworm (TAW) moths around the state.
Even with some cooler weather last week, moths continue to migrate northward into Iowa. During week 3 of the Iowa Moth Trapping Network (April 16 to April 22), our cooperators reported 83 black cutworm (BCW) and 110 true armyworm (TAW) moths around the state. Three additional significant flights of black cutworm occurred last week (refer to the Week 2 update for an explanation of significant flights).
Warm weather and strong winds during the second week of moth trapping pushed many moths northward into Iowa. During week 2 of the Iowa Moth Trapping Network (April 9 to April 15), our cooperators reported 95 black cutworm (BCW) and 46 true armyworm (TAW) moths around the state. Two significant flights of black cutworm occurred last week, as well as two potentially significant flights.
The 2023 moth trapping season is underway, and our volunteers began placing traps the week of March 26. Black cutworm (BCW) monitoring is a long-standing project in Iowa, and true armyworm (TAW) was added in 2017. Both of these pests are migratory, making it difficult to predict where populations will establish year to year.
