2019 UMN Cooperative Black Cutworm Trapping Network Report #2

Report #1 Weeks of April 6-12 and April 13-19, 2019

For more information: Black Cutworm Reporting Network

April 23, 2019


Sorry about the delay in reporting last week. Low numbers of migrating black cutworm moths found their way into southern MN.

Black cutworm moth captures April 6-12Figure 1: Maximum two consecutive night black cutworm captures reported by county (April 6-12).

One of the Blue Earth County pheromone traps captured a single moth the morning of April 9 (Figure 1). Captures picked up a bit April 13-19, the 3rd week of trapping, but trap captures were scattered and moth numbers were low (Figure 2). Traps in Faribault, Fillmore, Houston, Jackson, Mower, Nobles, Rock, Waseca, and Watonwan Counties picked up 1-3 moths over a two-night period. The captures in Fillmore and Jackson counties likely arrived April 14 or 15. All other captures probably arrived with April 18 systems.

While the trap network indicated that moths had migrated into the southern two tiers of MN counties, the numbers of moths captured were well below those that would indicate a high risk for crop damage. How many moths indicate risk?  For predictive purposes, when a trap captures eight or more moths over a two-night period, we consider it a significant capture. Significant captures indicate geographic areas where large migrations have arrived and they provide a “biofix” from which to calculate degree-days to predict cutworm development. 

Black cutworm moth captures April 13-19Figure 2: Maximum two consecutive night black cutworm captures reported by county (April 13-19).

Delayed spring field preparation and early-season weeds growth provide habitats attractive for egg laying female black cutworm moths. These conditions now exist across much of southern Minnesota.

Next week’s report will show even greater black cutworm moth activity and we will start calculating degree-days for cutworm development and damage based on significant pheromone trap capture dates.

During the spring, results of the 2019 trap network captures and predictions of BCW cutting will be posted weekly at: UMN Copperative Black Cutworm Network. There will be additional alerts for any BCW high-risk areas picked up by the network! More information on black cutworm biology and damage are locate at this site as well or at: UMN Extension - Black Cutworm.

This project is supported, in part, by the farm families of Minnesota and their corn check-off investment.

Until next week,

Bruce Potter and Travis Vollmer