Each year, Iowa State University’s IPM team monitors field crop pests to help inform farmers and scouting personnel about pest activity in Iowa. This year, our moth trapping network includes black cutworm (BCW) and true armyworm (TAW), two migratory pests of crops in Iowa that are unpredictable year to year and thus require monitoring.
To aid in this effort, we ask for volunteers around the state to establish trapping locations and report their findings. This year, we established 45 BCW and 45 TAW locations in 32 Iowa counties (Fig. 1) with the help of 8 ISU research farms and 34 private volunteers.
These volunteers allow us to accurately refine pest movement into the state and estimate scouting and treatment windows for growers based on intensive flights. An intensive flight for black cutworm moths occurs when 8 or more moths are captured in a pheromone trap over two nights. No such threshold exists for true armyworm moths yet, but monitoring is done to confirm presence in an area and support scouting activities.
No intensive flights have occurred for black cutworm yet, but moths of both species have been captured in several counties (Tables 1 and 2). As the trapping season continues, additional reports of moth captures will be provided. Ultimately, cutting dates for black cutworm will be predicted and provided in May following any intensive captures reported by our cooperators.
Surrounding states also monitor and report findings of BCW and TAW. If you are near the state borders, it may be beneficial to check these resources periodically. Some state resources are listed below, but others may be available online soon: