Final Iowa Moth Trapping Network Update for 2020

June 3, 2020 9:59 AM
Blog Post

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 36 cooperators participate from 34 counties in Iowa. A total of 78 traps (39 of each species) were placed and monitored during April and May. Because of these efforts, we were able to provide weekly updates of moth activity and predict cutting dates for BCW in Iowa.

Last week, our cooperators reported 183 TAW and 84 BCW moths statewide. Most of these reports occurred during the first half of last week. Typically, moth activity is winding down by this time, but this year we saw prolonged arrival of both species into the state. Moths were caught the first week of trapping, and large flights began during mid-April and continued through May.

No additional significant flights of BCW occurred last week. With updated degree day information, predicted cutting dates could extend through June 10 across the state. Continue to scout fields weekly until V5 to account for any prolonged arrival of BCW larvae into the area. If you see BCW larvae or evidence of feeding, please email bugtraps@iastate.edu. This can help us refine our predictions in the future.

Figures 1 and 2 show the total moth captures in each county from May 24 to June 1 for TAW and BCW, respectively.

TAW reports May 24 to June 1 2020
Figure 1. True armyworm moth captures from May 24 to June 1. The total moth count for the time period is noted on the map; highlighted counties without numbers indicate that traps are placed but no reports have been received. Data is current as of June 3, 2020.

BCW reports May 24 to June 1 2020
Figure 2. Black cutworm moth captures from May 24 to June 1. The total moth count for the time period is noted on the map; highlighted counties without numbers indicate that traps are placed but no reports have been received. Data is current as of June 3, 2020.

Follow the links to see reports from Weeks 1 and 2, Week 3, Week 4, Week 5, Week 6Week 7, and Week 8.

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:

Author: 

Ashley Dean Extension Program Specialist III

Ashley is an extension program specialist for field crop entomology at Iowa State University. She coordinates the Iowa Moth Trapping Network, develops educational resources for field crop pests in Iowa, and aids in the research efforts of the