Content by Adam Varenhorst

Dectes Stem Borer in South Dakota Soybeans
Fact sheet on Dectes stem borer in South Dakota soybeans

Aphid Populations Continue To Increase in Wheat
English grain aphid populations are continuing to increase in wheat. With increasing pressure, it is important to scout wheat fields to ensure that the populations do not cause yield loss.

Survey of Grasshoppers in South Dakota
Fact sheet on the abundance and species diversity of grasshoppers in South Dakota

Pesticide Personal Protective Equipment: Glove Selection
Safety gloves are one of the most-important pieces of pesticide personal protective equipment. Glove material is very important, as not all materials provide the same protection for different pesticide ingredients.

Monitor Alfalfa for Pea Aphid Activity
Pea aphids can cause yield reductions to alfalfa when large populations are present. Prolonged feeding by these populations can even cause the alfalfa fields to take on a “golden” color.

Malathion receives special local needs approval to treat red sunflower seed weevils in South Dakota from July 15 to August 31, 2025
The request was submitted and approved by the Environmental Protection Agency due to the large populations of red sunflower seed weevil present in South Dakota that are resistant to pyrethroid insecticides.

Alfalfa Weevil Populations Rapidly Increasing in Western South Dakota and Starting to Show up in Eastern South Dakota This Week
Recent degree day accumulations for alfalfa weevils in western South Dakota would suggest that alfalfa weevil larvae activity should be wrapping up for the 2025 season. However, recent scouting of alfalfa suggests otherwise.

Scout Corn for Black Cutworm Activity
Black cutworms are a migratory moth that moves into South Dakota during early spring. Although black cutworm caterpillars cause minor corn injury by feeding on leaf tissue, serious injury occurs when feeding results in the cutting of young corn plants.

Red Sunflower Seed Weevils in South Dakota
Fact sheet on red sunflower seed weevils in South Dakota

Alfalfa Weevil Activity Prediction Update: May 29, 2025
The lowest calculated degree days in South Dakota indicate that fourth instar larvae should be active, while the highest calculated degree days suggest that pupation is occurring in the field.