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Content by Patrick Wagner

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

Is it Time to Spray Red Sunflower Seed Weevils?

Red sunflower seed weevil adult activity is well underway on sunflowers in South Dakota. Even though the red sunflower seed weevil numbers are down, we are still observing populations in South Dakota that are above threshold.

A soybean leaf infested with numerous soybean aphids.

Soybean Aphids Exceeding Thresholds in Some Parts of South Dakota

There have been a few fields this week that were infested with soybean aphids that are getting closer to threshold. We have also received reports of insecticides being applied to manage soybean aphids in South Dakota.

True armyworm caterpillar on a corn leaf.

Reports of Pyrethroid Failures for True Armyworm Caterpillar Management

True armyworm caterpillars reached thresholds in oats and wheat in many areas of South Dakota recently. Management efforts to reduce populations had varying levels of success, with SDSU Extension receiving numerous reports of pyrethroid insecticide failures.

Gray beetle on a green alfalfa plant with purple flowers.

Watch for Blister Beetles in Later Alfalfa Cuttings

The frequent rain events experienced this summer has helped boost forage production. Although this is great for growers, the possibility of encountering blister beetles at harvest increases later in the summer.

Three bean leaf beetles. From Left: Brown beetle with black spots on a green leaf. Yellow beetle with black spots on a green leaf. Red beetle with black spots on a green leaf.

Bean Leaf Beetles Showing Up in Soybean

Despite the prediction of low overwintering survival we have observed bean leaf beetles in soybean this week. See our latest observations and management recommendations.

U.S. Environmental Protection Agency offices in Washington, D.C.

Update on Chlorpyrifos Use in South Dakota

As of June 30, 2025, the labeled uses for chlorpyrifos products for food and feed are limited to alfalfa, soybean, and wheat in South Dakota. Chlorpyrifos can no longer be used to treat sunflowers.

Cream colored larvae on white and green soybean stem on brown dirt.

Dectes Stem Borer Adults Detected in South Dakota Soybean

Dectes stem borer adults have been collected from soybean in Southeastern South Dakota this week. As a reminder, the larvae of insect pest are capable of reducing soybean yields from 0-17% due to its feeding activity inside of the main stem.

Blue container with lid visible that has a label indicating it is only for pesticide contaminated clothing/PPE.

How to Properly Launder Pesticide Contaminated Clothing

Many types of personal protective equipment are intended for single use only and should be discarded after use, but how do you wash reusable equipment and clothing contaminated with pesticide residue?

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.