By this time in the spring, moth activity typically quiets down a bit. Not this year – we were still seeing large flights of moths last week! True armyworm (TAW) activity picked up again with a total of 84 TAW moths reported across the state. Black cutworm (BCW) captures decreased compared to the previous week with a total of 55 BCW moths caught around the state.
A significant flight of BCW occurred in Washington County (southeast Iowa) on May 14. This is in addition to other significant flights that occurred in Washington County and throughout the state in previous weeks. We have already predicted cutting dates for BCW based on significant flights that occurred in April in southeast and central Iowa. We suggest using the estimated cutting dates as a baseline for scouting and continue to scout cornfields until V5 to account for any prolonged arrival of BCW into the area. For southeast Iowa (climate division 9), potential BCW cutting could extend into the first few weeks of June based on the significant flight on May 14.
Figures 1 and 2 show the total moth captures in each county from May 10 to May 16 for TAW and BCW, respectively.
Follow the links to see reports from Weeks 1 and 2, Week 3, Week 4, Week 5, and Week 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:
Ashley Dean Agriculture and Natural Resources Extension Specialist II
Ashley is an education extension specialist for field crop entomology at Iowa State University. She coordinates the Iowa Moth Trapping Network, the Regional Corn Rootworm Monitoring Network, and the Iowa Pest Alert Network. She also develops educational resources for field crop pests in Iowa and ...