This is our 14th week of monitoring moth pests in Ohio. Between July 21st and July 27th, we continued to monitor Corn Earworm (CEW) and Western Bean Cutworm (WBC). The statewide averages for WBC and CEW decreased in the majority of counties over the past week. We plan to continue monitoring for WBC and CEW into August and then will likely switch our traps over to fall armyworm.
Western Bean Cutworm
This week 21 counties monitored WBC (Figure 2) with a total of 54 traps. A total of 18 counties recorded having WBC this week, which is an increase from the previous week. However, the average moths per county experienced a drop to an average of 4.1 moths, almost 66% less than last week’s average of 13.2 moths. These numbers indicate we may be past the peak of WBC in Ohio. Counties with the highest averages included Sandusky (10.0), Huron (10.0), Lorain (8.0), Geauga (8.0) Lucas (14.0), and Wayne (10.5) (Figure 2). The numbers for WBC are expected to remain high, so counties with an average greater than 7.0 moths should consider inspecting their fields.
How to scout for WBC egg masses
A field of corn that is in the process of forming tassels is an ideal place to start looking for WBC eggs. Examine 20 plants in 5 different locations (100 plants total). Typically, eggs can be found on the underside of upright leaves near the tassel or on the upper side of leaves near the leaf collar. Newly laid eggs are usually a whitish color, and the older eggs can be dark purple (Figure 1). Treatment options should be considered if 5% of plants have egg masses. For optimal results, treatment should be applied when the majority of the eggs found are purple (indicating they are close to hatching).
To view a more detailed video on scouting – click here: https://youtu.be/qGjpwtfkObM?si=CFPzX1rlqt6jzyJw
For more information on how to scout WBC please visit: Western Bean Cutworm | Ohioline
Western Bean Cutworm Moth Map
Week #8
July 21st to July 27th, 2025
Corn Earworm
This week we monitored 32 traps in 15 counties across Ohio for CEW moths (Figure 3). The statewide averages of CEW decreased across the state with an average of 0.8 moths per county (Figure 4). Morgan County had the highest moth average, which was 5.3. Overall, the statewide averages of CEW have remained low since the beginning of June.
More information on CEW can be found here:
Corn Earworm in Field Corn; Watch for Molds | Agronomic Crops Network
Corn Earworm Moth Map
Week #8
July 21st to July 27th, 2025
