By Angie Peltier
Pheromone traps are set up at various locations throughout the state in order to register when a "significant" black cutworm flight, which occurs when nine or more moths are trapped over a 2-day period, has taken place.
Figure. Black cutworm. Note the small, black dagger-shaped marking on each outer wing.
A significant flight indicates that these migratory insects have made their way into the area this spring and are in populations significant enough that it is likely that they have found a mate and laid eggs. The eggs will hatch in a period of between 5 and 10 days. Significant flights can alert ag professionals about when they might begin scouting their corn fields for injury and larvae to ensure that action can be taken before significant injury occurs.
The black cutworm trap at the Northwestern Illinois Agricultural Research and Demonstration Center (NWIARDC) has not yet registered a "significant flight" in 2015. However, traps in Illinois counties to the North have. Iowa State University Entomologists have also commented on the fact that unlike past years, this year fewer of the traps in their trapping network have captured significant flights. Regardless of the reasons behind the NWIARDC's lack of a significant black cutworm moth capture, corn producers in the area are urged to begin scouting corn for injury.
Although, hatching larvae are small, they go through several molts and can cause more damage the larger they become. Additionally, although some corn hybrids contain Bt traits that offer black cutworm protection, not all do. Checking out Michigan State University's Dr. Chris DiFonzo, Handy Bt Trait Table can help to narrow down which Bt traits provide protection against black cutworms and other insects.