Sunday, April 24, 2011

Black Cutworm Flights Indicate Need for Scouting

Corn growers should start scouting corn fields May 4 and May 13 for Black Cutworm. There have been two intensive moth flights and given the dates of flights, these are suggested dates to scout for black cutworm in corn fields.
One trap is located north of St. Joseph on the 102 River Bottom and the other is south of Oregon on the Missouri River bottom. The catching of moths indicates when growers should examine fields but does not mean that we will have widespread cutting. Both traps picked up the two moth flights during the same time period. Also, statewide trapping of insect pests can be viewed on MU IPM Pest Monitoring Network website.
Black cutworm do not over winter in northwest Missouri but migrate from the Gulf of Mexico on strong spring winds northward. Typically, injury occurs from April to May as corn emerges.
Black cutworm passes through six to seven larval stages or instars. Larvae must be at the fourth instar to be large enough to feed on corn. Black cutworm can cut from the fourth instar to pupation which may last from two and one half to three weeks. Corn can be cut through the 5-leaf growth stage. Rarely, corn can be injured past this stage as they will feed into the base of the stalk damaging the growing point.
For more information, contact Wayne Flanary at 660-446-3724 or Heather Benedict at 660-425-6434, Regional Agronomists, University of Missouri Extension.

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