Insect & Pests

All Insect & Pests Content

Light colored moth on a yellow sunflower head.

Sunflower Moths Active in South Dakota Sunflowers

We have received reports of sunflower moths present on early planted sunflowers this week. The observed sunflower moth populations are above the recommend threshold of an average of 1 to 2 moths per five heads.

Dark green and tan curled caterpillars with an orange stripe along their sides.

True Armyworm Caterpillars Are Active in South Dakota Wheat

We have received a few reports of true armyworm caterpillars in wheat that are heavily feeding on the leaves. The big concern with these pests is that they will also clip wheat heads prior to harvest, so scouting is necessary to ensure that they don't cause yield losses.

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.

Small, green teardrop shaped insects on a green, soybean stem with pink flower.

Soybean Aphids Detected in South Dakota

While scouting soybean aphids this week we observed small colonies of 5 to 10 soybean aphid nymphs. This indicates that the soybean aphids are just starting to arrive in South Dakota soybeans and weekly scouting for them should be occurring.

Top: Green cloverworm caterpillar. Bottom: Cabbage looper caterpillar.

Green Caterpillars Causing Defoliation in Soybean

This week we observed several species of caterpillars in soybean fields. The most common species were the green cloverworm and the cabbage looper.

Rows of empty white, plastic pesticide containers.

2025 Pesticide Container Recycling

The South Dakota Department of Agriculture and Natural Resources is again offering pesticide container recycling services across the state. View a complete list of 2025 dates and locations.

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

Dectes Stem Borer Adults Are Active in Soybean: 2025 Management Recommendations

Dectes stem borer adults have been collected from soybean in Southeastern South Dakota. The larvae of this pest are capable of reducing soybean yields by 10-15% due to tunneling activity in the main stem. Learn some tips for scouting and managing them this season.