Content by Patrick Wagner

Alfalfa Weevils Are Active in Some Parts of South Dakota

Degree day accumulations indicate that alfalfa weevil larvae should be active throughout South Dakota.

Alfalfa Weevil Activity Prediction Update: May 22, 2025

Degree day accumulations for alfalfa weevil larvae indicate that third to fourth instar larvae should be active in fields throughout South Dakota.

Black Grass Bug Activity Ramping Up

Black grass bugs feed on fresh green growth, which can result in stunted plants and decreased forage quality. Monitoring and potential management of black grass bugs will be of increased importance this spring, especially if drought persists.

South Dakota Grasshopper Prediction for 2025

In 2025, it is likely that grasshopper populations will once again reach levels capable of causing issues in some areas of the state. Scouting should begin shortly after planting in areas where they were problematic in 2024 and continue throughout the growing season.

Spring is here, and so are the ticks!

As spring continues to bloom, more arthropods will begin to emerge from winter dormancy. Ticks are among the first to appear, and statewide reports have already been flowing in.

Management Recommendations for Soybean Aphids

In many fields across eastern South Dakota soybean aphid populations have reached economic thresholds, and there have been a lot of questions regarding the best approach to managing the 2024 outbreak.

Sunflower Moths Observed in South Dakota

Sunflower moths have been observed in South Dakota sunflower fields this week. Sunflower heads are most susceptible to damage caused by the sunflower moth caterpillars from the onset of flowering to when the ray petals begin drying.

It’s Time to Scout for Soybean Aphids

Small populations of soybean aphids were observed this week while scouting. Early scouting will ensure that populations do not rapidly increase and exceed the recommended economic threshold.

Potato Leafhoppers Becoming Prevalent

Potato leafhoppers are a migratory pest that impact South Dakota alfalfa each year. At this point in the growing season, they have become established and are now causing widespread issues.

Wheat Stem Sawfly Adults Observed in South Dakota

During the 2024 wheat stem sawfly survey, wheat stem sawfly adults were captured in northwestern South Dakota. Observation is used to determine areas where solid stem wheat varieties should be considered.