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Posted 21 July 2008. PMN Crop News.

Western Bean Cutworm Expands Its Reach

Pioneer Hi-Bred Recommends Early Scouting

Pioneer Hi-Bred International, Inc.

Des Moines, Iowa (July 18, 2008)--Recent western bean cutworm trappings by university entomologists and field professionals from Pioneer Hi-Bred, a DuPont business, indicate the pest continues to move eastward through the Corn Belt. As a result, experts from Pioneer recommend early scouting.


Pioneer agronomists and sales professionals in high-risk states are placing more than 200 western bean cutworm (WBC) pheromone traps. Pioneer also has partnered with university extension entomologists at several universities, including Iowa State University, University of Missouri, University of Illinois and others, for trapping and migration information.

WBC can reduce yields up to 40 percent in heavily infected fields. Trappings in late June and early July indicate WBC is continuing to move farther east. Nebraska, Iowa, Illinois, Indiana, Michigan, Minnesota, Wisconsin, Missouri and parts of Ohio have all seen the pest in recent years. This year, WBC has migrated farther into Ohio and potentially other states.

WBC can be detected by looking for a number of unique features. The forewings are a mixture of buff, tan and gray with a cream-colored bar extending four-fifths the length of the wing along the front edge. There also are two spots in the shape of a “full moon” and a “boomerang” touching the cream-colored bar near the mid-length of the wing.

Young WBC larvae feed on tassels and silks, but eventually tunnel through the silk channel to reach developing kernels. Direct yield loss occurs as larvae consume all or parts of developing kernels. Partially consumed kernels may be attacked further by ear molds or secondary insect feeders that enter the ear through the WBC feeding channel.

Growers can get in-plant protection against WBC. Herculex® I and Herculex® XTRA insect protection traits, available in Pioneer® brand hybrids, are the only traits on the market that protect against WBC.

“Pioneer hybrids offer growers a great amount of security,” says Michael Rupert, Pioneer agronomy research manager in Bloomington, Ill. “In times of high commodity prices, in-plant solutions such as Herculex I and Herculex XTRA technologies offer additional protection, allowing growers to produce an optimum crop.”

If growers have concerns or suspect WBC infestation, they can contact their local Pioneer sales professional or agronomist for management information. Growers also can visit university monitoring Web sites for current trapping locations.

“Growers need to continue to scout their fields,” says Rupert. “If a grower did not plant hybrids with Herculex I or Herculex XTRA insect protection, timely insecticide applications can be an effective treatment.”

Insecticide products, such as DuPontTM Asana® XL, are available against WBC and provide outstanding, longer-lasting control. With its unique cottonseed oil formulation, Asana® XL resists washoff and provides superior UV stability – even under intense sunlight. With its unique cottonseed oil formulation, Asana® XL resists washoff and provides superior UV stability – even under intense sunlight.

Jerry Harrington
800-247-6803, ext. 6908