Finishing up our eighth week of monitoring for the LEP Network, we are happy to announce that we have begun monitoring for corn earworm! While we are past the projected scouting season for black cutworm and true armyworm in Ohio, there were a handful of counties that still saw some of these springtime pests. This past week, Clinton County saw the highest average of CEW moths, Hardin County saw the highest for BCW, and Van Wert County saw the highest for AMW. The total number of counties participating in scouting this week is lower than usual due to setting up new CEW traps and retiring old BCW and AMW traps for this season.
Corn Earworm
As mentioned in last week's newsletter, this is our first week scouting for corn earworms in Ohio. While reports of this pest are low as of now, expect CEW numbers to increase as we get further into the season scouting for this damaging corn pest. The statewide average for CEW pests during this first week of scouting hit 0.89 during the week of scouting from June 3rd to June 9th. Counties with the highest averages included Clinton (5.0), Hardin (2.0), and Auglaize (1.0) (Figure 1). It is important to be ready for CEW pests in Ohio and scouting is the best way to stay ahead of any infestations before they happen. As the name implies, corn earworm is a common pest of sweet corn in its larval stage. When looking for a place to lay their eggs, CEW moths are attracted to fields that are in the early green silk stage of development; this is when fields will be most susceptible to damage. Caterpillars vary in color from light to dark but will always have the same characteristic markings (Figure 2). While scouting for the caterpillars of this pest is all but impossible, monitoring for adults (Figure 3) is important to predict larval damage in a field. To monitor for CEW moths, we are using green bucket traps with a lure that attracts adults to the trap. Traps are checked weekly, and an average is reported for each monitoring county. 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
Corn earworm moth map
Week 1
June 3rd to June 9th, 2024
Black Cutworm
The statewide average for BCW pests decreased from 0.61 during the week ending on June 2nd to 0.42 for the week ending June 9th. Counties with the highest averages included Hardin (4.0) and Van Vert (3.2) (Figure 4). As mentioned in our most recent newsletter, 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 the time corn is planted until it reaches the V6 stage of growth. 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 8
June 3rd to June 9th, 2024
True Armyworm
The statewide average for AMW slightly decreased from 0.43 moths for the week ending on June 2nd to 0.41 for the week ending June 9th. Counties with the highest averages this week included Van Wert (3.4), Hardin (3.0), and Trumbull (1.0) (Figure 5). 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. In addition to scouting corn fields, be sure to keep an eye on hay for armyworm and cutworm caterpillars, we have been receiving reports of high numbers in Van Wert County while scouting. 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
