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Adam Varenhorst

Associate Professor & SDSU Extension Field Crop Entomologist

605-688-6854

Berg Agricultural Hall 226
Box 2100A
Brookings, SD 57007

As the SDSU Extension Field Crop Entomologist Adam serves South Dakota stakeholders by addressing insect pest issues in field crops. He conducts applied research that focuses on corn, soybean, wheat and sunflower. Additionally, he assists the other extension entomologists to address questions pertaining to insect questions for the home and garden, urban insect pests and general entomology questions.

State & Regional Offices

SDSU Campus

Also by Adam Varenhorst

Greenish brown bugs on a white sweep net cloth.

Alfalfa Plant Bugs Showing Up in Abundance

There have been several insect pests showing up in alfalfa this season, including the alfalfa plant bug. We consider the above-average spring temperatures and drought-stressed plants in Eastern South Dakota to be the primary drivers of these issues.

Gray beetle resting on the purple blossom of an alfalfa plant.

Blister Beetles Already Appearing in Alfalfa

Large blister beetles populations were observed while scouting alfalfa this past week. While they usually aren’t an issue until after the first cutting, this early activity means growers should monitor alfalfa fields prior to harvest for the remainder of the season.

Left: Alfalfa weevil larvae. Right: Alfalfa weevil adult.

Alfalfa Weevils Are Active in South Dakota

Alfalfa weevil larvae are active across South Dakota. Although they had a somewhat slower start this year, we are now observing all instars of the larvae in alfalfa fields.