Content by Patrick Wagner

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.

Stable fly, face fly, and horn fly.

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.

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.

Nearly microscopic elongate organism.

Springtails Are Active in South Dakota

Recent reports of seemingly millions of very small insects moving around on driveways and around homes was the result of a springtail population boom. Springtails typically become a nuisance during drought conditions or saturating rains.

Dense swarm of mosquitoes in the evening sky

West Nile Virus Update: July 2, 2026

On June 15, 2026, the South Dakota Department of Health released a press release that the first West Nile Virus positive pool of mosquitos was detected in Brown County. Although much of the state is still experiencing drought, recent heavy rains will promote already active mosquito populations.

Sunflower moth, banded sunflower moth, and sunflower maggot adult.

Sunflower Pest Recap

During 2026, we will be producing a new weekly update on sunflower insect pest activity. This information will be attained via a sampling network of eight locations that are in central South Dakota.

Small shiny black beetle with two light tan stripes on elytra.

Alfalfa Should Be Scouted for Presence of the Palestriped Flea Beetle

Palestriped flea beetles have recently been observed in alfalfa fields in South Dakota. Large populations of palestriped flea beetles can cause rapid defoliation and stunt seedling alfalfa.