A pheromone trap network is being ran for monitoring flights of European corn borer (ECB) in conventional, non-Bt corn fields. We have 14 trap sites in 7 counties of ND including Barnes, Cass, Cavalier, Richland, Steele, Traill and Ward Counties. Last week, the Z-pheromone and the E-pheromone traps each captured only one moth in Cass County. This is the univoltine flight (one flight per year), which is the predominate ECB ecotype in ND, and typically emerges in mid-July. The damage from the univoltine ECB includes eardrop, stalk lodging and reduced corn yields when economic populations of ECB larvae tunnel inside stalks of corn. We will be posting weekly maps of the trapping results for European corn borer moths on the IPM website. Thanks for support from the North Dakota Corn Council.

The current degree day model for the univoltine ECB ecotype (base of 50⁰F) indicates that the flight is starting in SE ND (see table at right). As with other degree day models, it helps identify priority times for field scouting since the models pinpoint the occurrence of key biological events. In this case, the model is indicating the proportion of moths that have emerged. Use the Insect Degree Day application on NDAWN, select map, select 50⁰F for the base temperature and select ‘Degree Days’ for the map type. See NDAWN map below.

Janet J. Knodel

Extension Entomologist