The Ohio Lep Network is back for a second year of monitoring Lepidopteran (moth/caterpillar) ag pests in 15 Ohio counties. The counties that will be monitoring in 2023 include Auglaize, Brown, Gallia, Hardin, Highland, Lucas, Muskingum, Pike, Putnam, Trumbull, Van Wert, Wayne, Williams and Wood. Pest populations that will be monitored this field season are the black cutworm (BCW), true armyworm (AMW), European corn borer (ECB-IA, ECB-NY), corn earworm (CEW), and fall armyworm (FAW). In addition, a larger network of counties will report on Western bean cutworm later in the season. Updates on trapping will be reported weekly in CFAES’s C.O.R.N newsletter.
To start off our season, wing traps with lures to attract black cutworm and true armyworm were deployed the week of April 24th (Figure 1). Traps were checked between May 1st – 7th and results are reported below.
For information on corn varieties tolerant of various insect pests, please review the Handy Bt Trait Table: https://aginsects.osu.edu/bt-corn-trait-table
Figure 1. Wing trap set up in field. Wing traps are used to monitor both black cutworm and true armyworm moths. Photo credit: Amy Raudenbush.
Black cutworm
Black cutworm is an early season pest that is not able to overwinter in Ohio. The moths migrate from southern regions as temperatures begin to increase. Over the past week temperatures started off low, but increased towards the end of the week. The moth numbers reported in this newsletter were likely from the warmer nights that occurred at the end of the week. Black cutworm adults are a brownish color and can be identified by a single dagger shape on each forewing (Figure 2). Adult moths are attracted to fields with broadleaf weeds, such as chickweed and purple dead nettle, to lay eggs.
Figure 2. Black cutworm moth (BCW). Distinct black, dagger shaped markings on the forewing (circled in yellow). Photo credit: Curtis Young.
For our first week, traps were monitored between May 1st - 7th for BCW adult moths. Over the past week, we monitored 29 traps in 9 counties (Figure 3). Counties with the highest averages were Muskingum and Hardin counties (7 and 6 moths, respectively). Moths were not reported in four of the monitoring counties including: Auglaize, Brown, Henry, and Lucas. 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
- https://aginsects.osu.edu/sites/aginsects/files/imce/ENT_35_14%20BCW.pdf
- https://aginsects.osu.edu/sites/aginsects/files/imce/ENT_35_14 BCW.pdf
For corn varieties tolerant of BCW, please review the Handy Bt Trait Table: https://aginsects.osu.edu/bt-corn-trait-table
Black cutworm moth map
Week 1: May 1 to May 7, 2023
Figure 3. Average black cutworm (BCW) moths captured from May 1st to 7th. 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 from the south in April and May. Adults are a light tan moth that have 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.
We are also in our first week of monitoring for AMW. For our first week of monitoring, traps were monitored between May 1st - 7th. Over the past week, we monitored 30 traps in 10 counties (Figure 5). Counties with the highest averages were Wood, Van Wert, and Putnam Counties. (7, 6 and 6 moths, respectively). Moths were not reported in the following monitoring counties across Ohio: Auglaize, Brown, Henry, Lucas, and Muskingum. 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.
True Armyworm moth map
Week 1: May 1 to May 7, 2023
Figure 5. Average true armyworm (AMW) moths captured from May 1st to May 7th. 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.