Insect & Pests

All Insect & Pests Content

a brown bug with wings on a wood stick with a black background

Wheat Stem Sawfly Parasitoid: Bracon lissogaster

Factsheet on indentification and lifecycle of Wheat Stem Sawfly Parasitoid.

Testing Center on the South Dakota State University campus.

SDSU Extension Pesticide Applicator Testing Locations

Whether you are interested in becoming certified as a private or commercial pesticide applicator, SDSU Extension is proud to offer in-person pesticide applicator testing locations throughout South Dakota.

Small beetle with elongated black snout. Beetle is red-orange in color.

Vertento® Insecticide Approved for Red Sunflower Seed Weevil Management

Recently the Environmental Protection Agency approved a Section 18 Emergency Exemption label for Vertento® Insecticide for use on sunflowers for red sunflower seed weevil management in South Dakota. This exemption is effective from July 15 to August 31, 2026.

A brown and black cow standing in a feedlot with flies on its face.

Summer Fly Control in Feedlots

Just as longer days mark the beginning of summer, so does the arrival of increased number of flies in feedlots. Flies are not only are an annoyance, they can reduce performance and worsen heat stress. Successful control strategies start with sanitation.

Fly Management for Cattle

There are several species of flies that can reduce the production value of livestock, particularly during hot, dry weather. To manage these pests, it’s important to be able to accurately identify them and understand their life cycles.

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.

Numerous nymph grasshoppers feeding on corn.

Large Grasshopper Nymph Populations Detected in Southeast South Dakota

This week we received several reports of large grasshopper populations originating from southeast South Dakota. The populations were well above threshold and actively defoliating crops.

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

Keep an Eye on Your Wheat: True Armyworm caterpillars may be present

Every year, true armyworm caterpillars pose a threat to South Dakota wheat fields, and they most frequently show up during the end of June and early July. However, strong southerly winds during the spring can cause populations to show up earlier.

Circular holes in a green corn leaf. The holes are in a straight line.

European Corn Borer Caterpillars Are Active: Scout your conventional corn

European corn borer caterpillars have been observed in conventional corn at several locations. Indicators for presence of are a line of straight holes in the upper leaves that is often referred to as shot-hole injury.

Small shiny fly larvae with black heads on a brown plant root.

Fungus Gnats Affecting Soybean Emergence

We have recently received a report of a maggot attacking soybean seedlings. During most years, we would immediately expect this to be a case of seedcorn maggots, but it was fungus gnat larvae.