The Ohio Lep Monitoring Network has kicked off its third year of monitoring for Lepidopteran (moth/caterpillar) pests in agronomic crops. This year, we will be monitoring for black cutworm (BCW), true armyworm (AMW), corn earworm (CEW), and fall armyworm (FAW). In addition, a larger network of counties will report on Western bean cutworm (WBC) later in the season.
Our 2024 monitoring season has started off earlier than last year, with our first report of BCW and AMW moths from traps checked April 15th – 21st. To monitor for both BCW and AMW, wing traps with lures to attract the adults are deployed along the edge of fields and checked weekly (Figure 1).
Figure 1. A wing trap set up along a field edge. Separate traps are used to monitor BCW and AMW. Photo credit: Amy Raudenbush.
Black cutworm
Black cutworm is an early season agronomic pest. Adults are a brownish color and can be identified by a dagger shape on each forewing (Figure 2, circled in yellow). Adult moths are attracted to fields with broadleaf weeds, such as chickweed and purple dead nettle, where they lay eggs that then hatch and feed on developing plants.
Figure 2. Black cutworm moth with black, dagger shaped markings on the forewing (circled in yellow). Photo credit: Curtis Young.
Black cutworm is not able to overwinter in Ohio. The moths migrate from southern regions as temperatures begin to increase. Over the past week, we have had a mix of weather conditions in Ohio, including some warm temperatures, therefore, it is not surprising that some counties in Ohio have already started reporting BCW numbers.
During our first week, April 15th – 21st, we monitored 24 traps in 8 counties (Figure 3). Counties with the highest averages were Van Wert followed by Hardin (13.7 and 5.3 moths, respectively). Moths were not reported in three of the monitoring counties including: Auglaize, Pike and Wayne.
Counties with high trap numbers should plan to monitor BCW larvae after corn is planted, especially in fields with a lot of broadleaf weeds such broadleaf weeds, such as chickweed and purple dead nettle. For more information about BCW please visit: https://aginsects.osu.edu/sites/aginsects/files/imce/ENT_35_14 BCW.pdf
If BCW is a concern, and you are interested in reviewing corn varieties tolerant of BCW, please review the Handy Bt Trait Table: https://www.texasinsects.org/uploads/4/9/3/0/49304017/bttraittable_jan_2024.pdf
Black cutworm moth map
Week 1
April 15th to April 21st, 2024
Figure 3. Average black cutworm (BCW) moths captured from April 15th to 21st. 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 traps set up in that county.
True Armyworm
Similar to BCW, true armyworm (AMW) adults migrate to Ohio from southern regions in April and May. Adults are a light tan moth with a white dot on both wings (Figure 4). Moths are attracted to fields with grasses, winter wheat, barley, and rye cover crops, to lay their eggs.
Figure 4. True armyworm moth with white dot on wings (circled in yellow). Photo credit: Kylie Harbert.
Our first week of monitoring for AMW, April 15th – 21st, included 24 traps in 8 counties (Figure 5). Counties with the highest averages were Van Wert, and Auglaize counties (22.7 and 5 moths, respectively). Counties with high trap numbers should monitor for AMW larvae after corn is planted, especially in areas of grassy no-till fields or fields that had rye cover crop.
For corn varieties tolerant of AMW, please review the Handy Bt Trait Table: https://www.texasinsects.org/uploads/4/9/3/0/49304017/bttraittable_jan_2024.pdf
True Armyworm moth map
Week 1
April 15th to April 21st, 2024
Figure 5. Average true armyworm (AMW) moths captured from April 15th to April 21st. The bold number indicates the average moth count for the week, and the standard number in parentheses is the total number of traps set in that county.