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Lep Monitoring Network – Last week for Black Cutworm and True Armyworm Update # 7

After rounding out our seventh and final week of monitoring for black cutworm and true armyworm in Ohio, it can be noted that this past week, Trumbull County saw the highest average of BCW pests, while Van Wert County has continued its streak of seeing the highest average of AMW pests. Despite nearing the end of the season for these pests, it should be noted that Van Wert saw a drastic jump in AMW pest numbers this past week, averaging a whopping 10.8 pests per trap, with the max number in one trap hitting 23 true armyworm moths.

Black Cutworm

The statewide average for BCW pests decreased from 1.3 during the week ending on May 27th to 0.61 for the week ending June 2nd. Counties with the highest averages included Trumbull (6.5), Hardin (5.5), and Van Vert (5.2) (Figure 1). Counties with high trap numbers throughout the season should pay close attention to and plan to scout for BCW larvae. When scouting for BCW larvae, closely monitor fields with broad-leaved weeds, specifically chickweed, from when corn is planted until it reaches the V6 growth stage. For more information on how to scout BCW please visit: https://aginsects.osu.edu/sites/aginsects/files/imce/ENT_35_14 BCW.pdf

Black cutworm moth map

Week 7

May 27th to June 2nd, 2024

Figure 1. Average black cutworm (BCW) moths captured from May 27th to June 2nd. The bold number on the left indicates the average moth count for the week, followed by the standard number on the right which indicates the total number of active traps set up in that county.

True Armyworm

Similar to the previous trend we have been seeing, the statewide average for AMW decreased again from 1.5 moths for the week ending May 27th to 0.43 for the week ending June 2nd. Counties with the highest averages this week included Van Wert (10.8), Hardin (5.3), and Trumbull (2.0) (Figure 2).  As previously mentioned, be sure to scout fields after corn is planted in counties that have had high averages thus far, especially in fields that were previously planted to cover crops. 

It is also important to be scouting hay fields for AMW larvae at this time (Figure 3). Recently a field in Van Wert reported high numbers of AMW larvae. For more information on the True Armyworm and the threat they pose to Ohio crops, please visit: https://agcrops.osu.edu/newsletter/corn-newsletter/2020-18/true-armyworm-infestations

True Armyworm moth map

Week 7

May 27th to June 2nd, 2024

Figure 2. Average true armyworm (AMW) moths captured from May 27th to June 2nd. The bold number on the left indicates the average moth count for the week, followed by the standard number on the right which indicates the total number of active traps set up in that county.

Figure 3. True armyworm found in a hay field in Van Wert County this past week (May 27th to June 2nd). Photo credit: Curtis Young, OSU Extension, Van Wert County

Start Scouting for Corn Earworm

As mentioned in last week's newsletter, this will be out last week scouting for black cutworm and true armyworm pests in Ohio, and it is important to be prepared and ready for our next seasonal pest coming. For In next week's newsletter, expect to see reports beginning on the corn earworm (CEW) pest (Figure 4). To learn more about corn earworms, check out one of our previous newsletters: https://agcrops.osu.edu/newsletter/corn-newsletter/2019-27/corn-earworm-field-corn-watch-molds

Figure 4. Corn earworm feeding on an ear of corn. Photo Credit: Jack Dykinga, USDA Agricultural Research Service, Bugwood.org

Crop Observation and Recommendation Network

C.O.R.N. Newsletter is a summary of crop observations, related information, and appropriate recommendations for Ohio crop producers and industry. C.O.R.N. Newsletter is produced by the Ohio State University Extension Agronomy Team, state specialists at The Ohio State University and the Ohio Agricultural Research and Development Center (OARDC). C.O.R.N. Newsletter questions are directed to Extension and OARDC state specialists and associates at Ohio State.