Week 15 of our Lep (moth) monitoring covered July 20th – July 26th. WBC numbers are still increasing but are expected to slow down in the next few weeks. For more information, read below.
Western Bean Cutworm
This week, 20 counties monitored WBC using 55 traps (Figure 2). The statewide average continues to increase with an average of 10.4 (compared to 6.0 last week). Similar to previous years, northwest Ohio seems to be trapping the bulk of WBC. Several counties in Northern Ohio continue to be above our scouting threshold of an average of 7.0 moths per week. These include Fulton (10.0), Henry (9.7), Lucas (91.0!), Sandusky (39.0), Trumbull (10.0), Wayne (10.5), and Williams (21.0). Counties above the threshold are encouraged to scout their fields for WBC egg masses.
How to scout for WBC egg masses
Corn that is in the process of forming tassels is an ideal place to look for WBC eggs. To scout: 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.
To view a more detailed video on scouting – click here: https://youtu.be/qGjpwtfkObM?si=CFPzX1rlqt6jzyJw
Western Bean Cutworm Moth Map
Week 8
July 20th – July 26th, 2026
Corn Earworm
This week we monitored corn earworm in 17 counties, with a total of 36 traps. Most monitoring counties continue to report low CEW numbers, under the threshold of an average of 7.0 moths per week. (Figure 3). Henry is the only county above threshold with an average of 14.0 moths. The statewide average is holding steady with a slight increase to 1.4 from 1.0 last week.
Corn Earworm Moth Map
Week 8
July 20th – July 26th, 2026
