By Bruce Potter
The black cutworm can be a significant pest of corn, sugarbeets and other crops. Because they cannot survive our Minnesota winters, the risk of economic crop loss depends on how many moths arrive and when they arrive with respect to crop development.
In some areas of Minnesota, planned fall tillage that did not happen and the later start to 2019 spring fieldwork both increase the proportion of fields that are attractive egg-laying sites for early-arriving migrant moths. Additionally, more corn acres are expected to be planted to hybrids susceptible to black cutworm damage.
To help predict risk of economic damage and help time scouting efforts, the UMN Cooperative Black Cutworm Trapping Network is once again operating during 2019. Each day, cooperators check their pheromone traps to look for moths that have migrated into the state. The timing of arrivals of large numbers of moths is used to predict when, and to a limited extent where, risk of damaging populations of black cutworm larvae is greater.