Moth trapping in Iowa is underway. Each year, we monitor field crop pests to help inform scouting activities in Iowa. In 2020, our moth trapping network includes black cutworm (BCW) and true armyworm (TAW; Figure 1). Both of these pests are migratory, making it difficult to predict where populations will establish year to year.
We ask for volunteers around the state to set up traps (Figure 2) to monitor BCW and TAW flights in Iowa. This year, 36 volunteers established 39 traps of each species (78 total traps!) in 34 counties in Iowa.
These efforts allow us to refine pest movement into the state and estimate scouting and treatment windows for farmers. An intensive flight of BCW occurs when 8 or more moths are captured in a pheromone trap over two nights. No such threshold exists for TAW, but monitoring allows us to inform farmers in the area and support scouting activities.
No significant flights of BCW occurred during the first two weeks of moth trapping.
No moths were reported in March, but reports quickly spiked the first week of April. The first TAW flights occurred April 1, and the first BCW flights occurred April 2. Counties with reports are shown in Figures 3 and 4.
April 6 and April 8 had the highest reports to date. On April 6, 23 TAW and 8 BCW moths were caught across the state. On April 8, 23 TAW and 6 BCW were caught across the state. Counties with reports are shown in Figures 5 and 6.
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: