Western Bean Cutworm trapping in the Panhandle and Southwestern NE

2026 Weekly Update (July 3): overall numbers are two weeks earlier than they were at this time last year.

The Western bean cutworm can be a serious pest in corn and dry beans. When their populations or infestations exceed thresholds, insecticide treatment is warranted, and timely treatment is crucial for management success. Moth flight data can be used to inform timing of in-field scouting and treatment. However, insecticide treatment should not solely rely on moth flight data.

• Table 

For corn, a match between moth flight and the late whorl to early tassel stage of corn can result in high levels of infestation. For beans, if the cumulative moth catch at the peak moth flight (50 percent emergence) per green bucket trap is < 1200, between 1200 and 1700, and > 1700, the risk of significant damage is low, moderate, and high, respectively. Note that it is a risk assessment. Actual bean damage and economic risk from larval feeding require scouting.

More information on scouting, treatment recommendations, and insecticide options https://cropwatch.unl.edu/2020/scouting-and-treatment-recommendations-western-bean-cutworm/. 

Cumulative moth catch numbers will be updated weekly. Green bucket traps are monitored by UNL PREEC Entomology Lab (Scotts Bluff and Sioux Counties), John Thomas (Nebraska Extension Educator; Box Butte County), Samantha Daniel (Nebraska Extension Educator; Chase, Dundy, Perkins Counties), and Dr. Vinicius Zuppa (Nebraska Extension Educator; Cheyenne County). Weekly trap data are compiled by the UNL PREEC Entomology Lab.

-University of Nebraska-Lincoln