Western Corn Rootworm Hatch Underway Across Central Illinois

Larry Bledsoe and his Purdue University entomology colleagues have a long tradition of being the first to report the annual hatch of western corn rootworm larvae. Larry  indicated to me and some other entomologists that hatch began to occur on June 2 on one of the research farms near the Purdue University campus.

Provided below is a list (19 years) of western corn rootworm hatch dates (for central Illinois and central Indiana) taken from previous Pest Management and Crop Development Bulletin articles (since 1996) and based upon observations by Larry Bledsoe and other  Purdue University entomologists.

  • 1996–June 12
  • 1997–June 13
  • 1998–late May (no precise date reported)
  • 1999–June 1
  • 2000–May 22
  • 2001–May 16
  • 2002–May 31
  • 2003–May 29
  • 2004–May 28
  • 2005–May 31
  • 2006–May 29
  • 2007–May 18
  • 2008–June 4
  • 2009–June 1
  • 2010–June 3 (second instars observed)
  • 2011–June 6
  • 2012–May 4–6 – Earliest observation of hatch by Larry Bledsoe in 35 years!
  • 2013 – June 4
  • 2014 – June 2

A quick review of these dates reveal the considerable range (5 weeks)  in the initiation of hatch: from May 4-6, 2012 (earliest) to June 13, 1997 (latest). In most years, you would be correct in predicting hatch would occur in late May and early June. So, it seems that we are off to a typical year in terms of hatch for this important insect pest of corn. I encourage producers in the coming weeks to report any significant root injury that may be taking place. I look forward to sharing the results of our root evaluations in July with the readers of this Bulletin.

Mike Gray