Black cutworm (BCW) is a migratory pest that arrives in Iowa with spring storms each year. It is sporadic and unpredictable, making it essential to scout to determine whether BCW larvae are present in a field and management is required. Since much of the corn planting around the state is complete and many fields have emerged, now is a good time to begin scouting for larvae.
Even though the weather has been variable this past week, one thing is certain: black cutworm is moving through Iowa. During week 2 of the Iowa Moth Trapping Network (April 4 to April 10), our cooperators reported 122 total black cutworm (BCW) and 21 true armyworm (TAW) moths. Windy conditions last week likely helped move so many moths into the state. Both species take advantage of powerful low-level jet streams at night to move long distances from their overwintering sites in the south.
The 2021 moth trapping season is underway, and our volunteers placed traps the week of March 28. Black cutworm (BCW) monitoring is a long-standing project in Iowa, and true armyworm (TAW) was added in 2017. Both of these pests are migratory, making it difficult to predict where populations will establish year to year.
The black cutworm (BCW) is a migratory pest that cuts and feeds on early vegetative-stage corn. Black cutworm moths arrive in Iowa with spring storms each year. These moths lay eggs in and around fields and the emerging BCW larvae cut seedling corn. The sporadic nature of this pest makes scouting essential to determine if management is needed. Scouting for BCW larvae helps to determine if an insecticide application will be cost effective.
By Adam Sisson, Integrated Pest Management; Laura Jesse, Plant and Insect Diagnostic Clinic; and Erin Hodgson, Department of Entomology
Scouting for black cutworm larvae helps to determine if an insecticide application will be cost effective.
By Erin Hodgson, Department of Entomology, Adam Sisson, Integrated Pest Management, and Laura Jesse, Plant and Insect Diagnostic Clinic.
By helping monitor the arrival of cutworm moths, industry and farmer cooperators provide data that helps Iowa State experts track pest activity, which in turn helps growers know when to scout and make treatment decisions.
