Volume 58 Number 6 Date 06/06/2013
BLACK CUTWORM - Larval infestations in corn have been observed in Columbia, Green Lake, Marquette, Waupaca and Waushara counties. Damage estimates were low and ranged from 0.5-2.5%, with the exception of one Marquette County field in which 23% of plants were injured. Larvae observed in the infested fields were about ½ inch in length. The primary cutting period is now under way and could extend through late June this year. Crop consultants and field scouts should carefully inspect corn for evidence of this pest in the next 2-3 weeks. A rescue treatment is justified if more than 3% of plants are damaged.
EUROPEAN CORN BORER - The spring flight of European corn borer moths began three weeks ago and egg deposition is now occurring on weeds, vegetables and various hosts other than corn. No moths were registered this week at any of the DATCP black light trap locations.
CORN ROOTWORM - Excessively wet soils and a delayed corn planting season suggest conditions may prove unfavorable for larval establishment this month. The first larvae are emerging in the far south, with 50% hatch projected for June 15-19 in the Beloit area and June 22-27 near Madison. This event occurs from 684-767 degree days (base 52°F).
TRUE ARMYWORM - Moderate flights have been documented at a few locations since mid-May, signaling a potential for larval outbreaks in small grains and corn. Reduced tillage corn fields following sod or small grains cover crops, and fields with early-season grassy weed pressure, are candidates for armyworm problems. Damage usually appears first at the margins of fields where the worms have migrated from another food source.
WESTERN BEAN CUTWORM - Pheromone trap installation is planned for the next 2-3 weeks statewide. If warmer weather prevails this month, the first moths could emerge by early July. Persons interested in participating in the program should email Tracy Schilder at firstname.lastname@example.org before June 12. Please supply your name, address, telephone number, and specify the number of traps to be placed.
-- Krista Hamilton, DATCP Entomologist