No. 12 Article 5/June 10, 2005

Corn Rootworm Reports Trickling In

The first reports are in. The article "Corn Rootworm Hatch Confirmed" from the Bulletin last week detailed the first detection of corn rootworm larvae in Indiana. As predicted, reports from Illinois were soon to follow. Jim Donnelly, Ag View FS, floated roots from a field northeast of Princeton (Bureau County) last week and found one larva approximately 1/8 inch long. On Monday, Matt Montgomery, crop systems educator for Sangamon-Menard counties, found rootworms in three separate fields near Virden and Petersburg. Darren Bakken, a crop sciences master's degree candidate, and Dan Lamoreux, an IPM summer intern, also found first-instar corn rootworm larvae near Mahomet.

Corn rootworm larva found in Bureau County, June 2, 2005 (photo courtesy of Jim Donnelly).

Based on degree-day accumulations (base 52°F, 4-inch soil profile), 50% of rootworm larval hatch will occur after the accumulation of 684 to 767 degree-days. To determine degree-days accumulated near you, visit the degree-day maps and project heat units at the Degree-Day Calculator.--Kelly Cook

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