Western Bean Cutworm Monitoring is Underway in Ohio

Traps were deployed for Western bean cutworm (WBC) monitoring the week of June 14th. The first trap counts were collected from June 21 – 27, and monitoring counties reported a total of 16 WBC adults (0.25 statewide average moths per trap; Figure 1). There are currently no counties at the WBC threshold requiring scouting for egg masses. 

Western bean cutworm is a pest of corn in Ohio and has increasingly caused concern for growers since reports of resistance to Cry1F hybrids. Monitoring for WBC is an important tool to track populations and make management decisions for our growers. Monitoring for WBC adults requires green bucket traps set with a pheromone and checked weekly (Figure 2). When trap counts result in an average of more than 1 moth/day (or a county average of 7 or more moths), we recommend scouting for WBC egg masses. While the pheromone is specific to WBC, occasionally other moth species can be found in the trap, such as yellow striped armyworms. It is important to look for identifying features on WBC moths, which include boomerang and dot markings on the wings (Figure 3).

Figure 1. Average Western bean cutworm adult per trap (in blue) followed by the total number of traps monitored in each county (in white) for the week ending June 27th, 2021. Map developed by Suranga Basnagala, Ohio State University, using ArcGIS Pro.

Figure 2. Western bean cutworm green bucket trap deployed at the edge of a cornfield. Photo credit: Amy Raudenbush.

Figure 3. Adult Western bean cutworm moth. To identify, look for boomerang structure and dot on wings. Photo credit: Amy Raudenbush.

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.