Reports are coming in of large grasshopper populations throughout South Dakota this summer and early fall. While these populations will continue to decline, there is still the possibility for significant populations to remain until after the first hard frost.
In areas where grasshopper populations have been consistently high, it is important to scout emerging winter wheat for injury, and manage grasshopper populations when necessary. The limited amount of green vegetation in the fall makes the newly emerging winter wheat very attractive to grasshoppers. Grasshoppers are capable of causing stand loss to emerging winter wheat by clipping the plant back due to the limited amount of foliage on seedlings. This type of injury will be more noticeable on the field edges as grasshoppers reside in the vegetation along field margins. Before and after planting, farmers should monitor fields and pay close attention to the margins to determine grasshopper population densities.
Grasshopper management options before planting
Management should be considered if grasshopper populations in the field and non-crop borders are in the range of 11-20 grasshoppers per square yard prior to planting. Management options to consider include:
Grasshopper management options after planting
If grasshopper populations are observed causing severe defoliation or clipping in newly emerged wheat, it is important to determine if the populations are above 11-20 grasshoppers per square yard. Additionally, determine how far into the field the grasshopper populations are. Management options to consider for emerged wheat include:
Source: Adam J. Varenhorst, South Dakota State University
Update your browser to view this website correctly. Update my browser now