Integrated Crop Management

Earliest capture ever for western bean cutworm in Iowa

It was quite a surprise today (June 18) when I received an e-mail confirming the first capture of an adult western bean cutworm in Iowa for 2007. Ben Linn, and previously his sister Sara, have operated a blacklight trap on their parents' farm near Correctionville in Woodbury County now for six years. Their earliest collection of an adult western bean cutworm has previously been June 24 but sometimes coming as late as July 10 (Table 1). Ben sent a photograph showing the moth on the day's newspaper.

The first confirmed western bean cutworm of 2007 was captured on June 18 in Woodbury County, Iowa. (Ben Linn) [1]The first confirmed western bean cutworm of 2007 was captured on June 18 in Woodbury County, Iowa. (Ben Linn)

This early capture date of a western bean cutworm suggests two items. First, our pheromone trapping network across Iowa was scheduled to begin on June 20, so we should be right on target for capturing the first moths as soon as the traps go up.

Second, moths are going to be attracted to corn that is in the pretassel and beginning tassel stages. Corn fields in these growth stages but not planted with a Herculex® I or Herculex® Xtra hybrid should be scouted for eggs and newly hatching larvae about a week after the first moth capture. I'll provide more information next week on scouting recommendations for this insect.

Table 1. Six-year blacklight captures of western bean cutworm adults from Woodbury Co., Iowa, 2002-2007.

Year First Capture Peak Capture Last Capture Total
2002 June 28 July 13 August 11 12,739
2003 July 10 August 1 August 17 244
2004 July 5 July 23 August 10 531
2005 June 28 July 13 August 10 1,328
2006 June 24 July 15 August 14 1,183
2007 June 18 -- -- 1

Marlin E. Rice is a professor of entomology with extension and research responsibilities.

This article originally appeared on page 181 of the IC-498(15) -- June 18, 2007 issue.


Source URL:
http://www.ipm.iastate.edu/ipm/icm//ipm/icm/2007/6-18/wbc.html