Western bean cutworm or WBC is an insect pest whose larvae feed on the kernels, leaves and other parts of the corn plant. Iowa State University coordinates a WBC monitoring network which records adult moth trap captures in Iowa. Trap captures can be used to help determine when to begin scouting for this insect pest. The results also provide a handle on how heavy the infestations are in various areas of the state each year.
Adam Sisson of ISU's Corn and Soybean Initiative, and Laura Jesse, who runs the ISU Plant and Insect Diagnostic Clinic at Ames, provide the following summary of WBC activity for 2010.
Trap information helps ISU alert growers as to when to scout
In 2010, there were 32 WBC traps located across 23 of Iowa's counties. Trapped moths were first recorded in Iowa on June 15 in Clayton County. Fayette County reported the most captures with 1,218 moths and a few counties, Marshall and Ringgold, had traps but no moths recorded. Overall, 2,657 WBC moths were reported in Iowa in 2010.
Participants in the trapping network were supplied with pheromone lures and instructions on how to build jug style traps out of milk cartons. Some participants used wing style traps. The pheromones lured moths to the traps and cooperators then counted moths and reported this data to Iowa State University's WBC monitoring network website. This trapping information was used in combination with degree day accumulations to alert growers as to when to scout for WBC in their fields, as was explained in a July 2010 ICM News article.
For more information on western bean cutworm, see the previous ICM News article "Use Treatment Thresholds for Western Bean Cutworm."