Monitor Emerging Winter Wheat for Grasshopper Populations

By Adam Varenhorst and Philip Rozeboom et.al

During 2025, large grasshopper populations have been observed in many areas of South Dakota. These populations have required management in other crops and will probably be an issue for winter wheat when it begins to emerge. 

Common Species

The most common grasshopper, pest species in South Dakota include the twostriped grasshoppers (Figure 1), differential grasshopper (Figure 2), and the redlegged grasshopper (Figure 3). Because many crop and non-crop hosts are starting to naturally dry down during this time of the season, grasshopper populations will be actively seeking alternative food options including winter wheat seedlings.

Scouting and Management

It is important to scout emerging winter wheat fields before and after planting for grasshopper numbers and feeding injury, especially in areas where large grasshopper populations are being observed. Grasshoppers can cause stand loss by clipping back the emerging plants. This type of injury will be more noticeable along the field margins, as grasshoppers reside in the nearby vegetation.

Prior to Planting

Before planting, scout the vegetation around the field edges and count the number of grasshoppers that are present in approximately one square yard. Management should be considered if 11-20 grasshoppers per square yard are present in the non-crop borders.