Insect & Pests

All Insect & Pests Content

A nest of Asian Needle Ants.

No Documented Sightings of Asian Needle Ants in South Dakota

Despite reports from major news networks citing that Asian needle ants are in South Dakota, we have no evidence that the ant is established or has ever been documented in the state.

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

Green leafhopper with clear wings.

Aster Leafhoppers Showing up in South Dakota Wheat

Aster leafhoppers are present in wheat again this spring. For the last few years, aster leafhoppers have been a common occurrence in South Dakota wheat.

Bird cherry oat aphids, English grain aphids, Greenbugs.

Don’t Forget To Scout for Aphids in Wheat

Aphids are present in South Dakota wheat fields, and that means it’s time to start scouting.

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.

Green corn leaf with ragged holes through-out caused by common stalk borer feeding.

Start Scouting for Common Stalk Borer Activity

Enough degree days have accumulated in some areas of South Dakota for common stalk borer caterpillars to start moving to corn end rows.

Purple-brown caterpillar with orange head on a green corn leaf.

Common Stalk Borer Activity Estimate: June 5, 2025

In the southern counties of South Dakota, degree day estimates indicate that common stalk borer caterpillars are beginning to move from weedy hosts along field edges into corn fields.

Small black and yellow beetle feeding on the green leaf of a canola plant.

Start Scouting Canola for Flea Beetle Activity

There are three species of flea beetles that commonly infest canola and feed on the leaves. The main concern occurs early in the season when these beetles can rapidly defoliate the plants.

Gray beetle with long antennae.

Dectes Stem Borer in Soybean Survey: 2023 and 2024 Results

During the 2023 and 2024 growing seasons, researchers at SDSU surveyed soybean in Eastern South Dakota for the presence of Dectes stem borer adults.