Western bean cutworm flight and egg masses increasing

Christina DiFonzo<difonzo@msu.edu>, Michigan State University Extension, Department of Entomology -

Recent lower temperatures may cause western bean cutworm egglaying to increase, especially in corn fields.

There are about 70 traps in the western bean cutworm network in 23 Michigan counties. Traps in Branch/Hillsdale counties picked up a moderate flight last week (tens of moths). This week, moth numbers in Montcalm County increased (100-plus in some traps) and we found a few egg masses. With the lower temperatures, egglaying should pick up, especially in areas that got some rain on Friday (July 19, 2013).

The variability in corn development, both within a field and from field-to-field, will benefit western bean cutworms. Females are great at finding pre-tassel corn, and this year they will be able to find attractive egglaying sites for many weeks. I am not sure if or how this will impact infestation of dry beans. Perhaps western bean cutworms will spend more time and lay more eggs in corn fields versus beans. On the other hand, late-planted dry beans may still be very attractive to moths and, depending on flight levels, whose fields may still need to be treated.

Dr. DiFonzo's work is funded in part by MSU's AgBioResearch.

This article was published by Michigan State University Extension. For more information, visit https://extension.msu.edu. To have a digest of information delivered straight to your email inbox, visit https://extension.msu.edu/newsletters. To contact an expert in your area, visit https://extension.msu.edu/experts, or call 888-MSUE4MI (888-678-3464).

Did you find this article useful?

You Might Also Be Interested In

Tag List
  • agriculture,
  • corn,
  • dry beans,
  • field crops,
  • msu extension
Michigan State University
  • Spartans Will.
  • © Michigan State University

MSU is an affirmative-action, equal-opportunity employer, committed to achieving excellence through a diverse workforce and inclusive culture that encourages all people to reach their full potential.

Michigan State University Extension programs and materials are open to all without regard to race, color, national origin, gender, gender identity, religion, age, height, weight, disability, political beliefs, sexual orientation, marital status, family status or veteran status. Issued in furtherance of MSU Extension work, acts of May 8 and June 30, 1914, in cooperation with the U.S. Department of Agriculture. Quentin Tyler, Director, MSU Extension, East Lansing, MI 48824. This information is for educational purposes only. Reference to commercial products or trade names does not imply endorsement by MSU Extension or bias against those not mentioned.

The 4-H Name and Emblem have special protections from Congress, protected by code 18 USC 707.

We comply with the Federal Trade Commission 1998 Children’s Online Privacy Protection Act (COPPA).