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Content by Adam Varenhorst

Gray beetle with long antennae.

Dectes Stem Borer in South Dakota Soybeans

Fact sheet on Dectes stem borer in South Dakota soybeans

Green aphid with black cornicles and black patterns on legs.

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.

Grasshopper with red hind tibia. It’s sitting on a green grass stem.

Survey of Grasshoppers in South Dakota

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

Examples of three commonly used protective gloves used for pesticide applications.

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.

Green aphid with red eyes and cornicles with black tips.

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.

Adult red sunflower seed weevil on a sunflower leaf.

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.

Plastic bag containing numerous green larvae.

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.

A small green corn plant that has been cut and is laying on the ground.

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-brown colored weevil with bent antennae originating on the elongated mouthparts.

Red Sunflower Seed Weevils in South Dakota

Fact sheet on red sunflower seed weevils in South Dakota

Green alfalfa weevil larvae with a white stripe running down its body.

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.