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Agronomic Crops Network

Ohio State University Extension


Lep Monitoring Network Update #10 – Trap Counts for CEW, WBC, and ECB (IA & NY)

The Ohio Lep Network is continuing to monitor moth pests across Ohio. As we enter our tenth week of reporting, we will continue population reports on corn earworm (CEW), Western bean cutworm (WBC), and both variations of European corn borer (ECB - IA & NY).

While monitoring for black cutworm (BCW) and true armyworm (AMW) have both ended for this season, it should be noted that Van Wert County is seeing an increase in both BCW and AMW populations. Across Van Wert County there were an average of 19.5 BCW moths per trap, and 9.5 AMW moths per trap, with there being 12 traps for each in the county.

For more information on these pests and many more, check out our website:

Chasing the Corn Earworm
This is our fourth week monitoring the corn earworm (CEW) pest. Nine counties across Ohio monitored for CEW populations using 13 total bucket traps. The county with the highest average moths was Brown County, which had an average of 24 moths (Figure 1).

Corn Earworm (CEW) is a common pest that we see in Ohio and can be seen in corn, tomato, and legume fields. For corn fields, CEW is typically more of a pest for sweet corn compared to field corn. CEW moths are most attracted to fields in the early green silk stage, and lay their eggs, which upon hatching cause ear-feeding damage, attract birds, and invite the possibility of mold. Most CEW damage is seen near the tip of the corn. CEW are drawn to these corn fields in the early green silk stage in an effort to lay their eggs (Figure 2). CEW are difficult to find during scouting, and have a variety or color variations ranging from dark brown, brown, tan, and green, and may even feature a pink hue. Adult moths are tan to light brown and feature many dark blotches, and feature a large bold spot halfway between the body and wing tip (Figure 3).   For more information on CEW and the threats they pose, check out our previous newsletter:

Corn Earworm Moth Map
July 4th – July 10rd, 2023

Figure 1. Average corn earworm moths (CEW) captured from July 4th- July 10th. The bold number on the left indicates the average number of moths captured. The second number on the right indicates the number of traps monitored in each county.

Figure 2: A single CEW egg on a corn leaf. Photo Credit:

Figure 3: An adult CEW moth, showing typical characteristics, such as the dark blotches on a lighter-colored body. Photo Credit:

Watching the Western Bean Cutworm
This is our third week reporting on adult Western bean cutworm (WBC) populations across Ohio. Overall, 19 counties across Ohio monitored for WBC populations using 61 total bucket traps. Most counties had less than one moth per trap (Figure 4).

WBC is a common Ohio pest affecting dry beans and corn and was historically found in the western Corn Belt. However, staring in 2000, damage was seen in Minnesota and Iowa, in 2006 the pest reached Ohio. Most of the moths have been caught in the northwest and west central parts of Ohio. Adult WBC emerges in late June through early July. Adult moths can be identified by three unique characteristic markings: a white stripe on the top edge of the forewing; a light brown, tan dot on the wing; and finally a crescent-shaped mark behind the dot (Figure 5). Unlike many other pests, there is only one generation per year, with moths laying eggs in egg clusters from 5 to 200 eggs that will hatch within 5-7 days. The eggs are first white, then tan, then a dark royal purple (Figure 6). Scouting for WBC eggs is recommended when your county levels are averaging more than 7 moths per week. To scout for eggs or larvae, select 20 consecutive plants, at 5 random locations, and inspect the upper 3-4 leaves and silk for eggs. For more information regarding the Western bean cutworm, visit our previous article:,corn%20in%20Iowa%20and%20Minnesota.

Western Bean Cutworm Moth Map
July 4th – July 10rd, 2023

Figure 4. Average western bean cutworm moths (WBCW) captured from July 4th- July 10th. The bold number on the left indicates the average number of moths captured. The second number on the right indicates the number of traps monitored in each county.

 Figure 5: An adult WBC moth displaying the characteristic crescent shape on the wings, and white dot above. Photo Credit:

Figure 6: WBC larvae hatch from their eggs, the royal purple eggs will hatch in 24 hours, however oher colors indicate larvae not ready to hatch yet. Photo Credit:

Exploring the European Corn Borer
This is our eighth week monitoring the European corn borer with an average of 0 IA variants and 0 NY variants being reported from July 4th- July 10th (Figure 7). In total, 9 counties across Ohio are monitoring for both ECB variants.

The European Corn Borer (ECB) is a common corn pest of Ohio that bores into corn stalks; these pests cause corn stalk disease, stalk breakage, and ear drop which reduces corn yield. ECB overwinter in corn stalks, and in the early spring will emerge as moths, which then deposit the next generation on mid-whorl stage corn. These eggs hatch and first feed on foliage, before later tunneling into the mid-ribs and stalks of the corn. Male and female adult moths look different, but are typically a straw or light brown color, with a dark wavy line two-thirds of the way outer edge of the hindwing (Figure 8). For more information about the European Corn Borer visit our website:

European Corn Borer Moth Map
July 4th – July 10rd, 2023

Figure 7. Average European corn borer moths (ECB) captured from July 4th – July 10th.The bold number on the left indicates the average number of moths captured. The second number on the right indicates the number of traps monitored in each county. Both variants had a total of 0 moths across all our counties in Ohio.

Figure 8: ECB moths, displaying the differences you can see in color between male and female moths. Photo Credit:

Crop Observation and Recommendation Network

C.O.R.N. Newsletter is a summary of crop observations, related information, and appropriate recommendations for Ohio crop producers and industry. C.O.R.N. Newsletter is produced by the Ohio State University Extension Agronomy Team, state specialists at The Ohio State University and the Ohio Agricultural Research and Development Center (OARDC). C.O.R.N. Newsletter questions are directed to Extension and OARDC state specialists and associates at Ohio State.