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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

Red-brown colored weevil with bent antennae originating on the elongated mouthparts.

Red Sunflower Seed Weevils in South Dakota

Fact sheet on red sunflower seed weevils in South Dakota

Green alfalfa weevil larvae with a white stripe running down its body.

Alfalfa Weevil Activity Prediction Update: May 29, 2025

The lowest calculated degree days in South Dakota indicate that fourth instar larvae should be active, while the highest calculated degree days suggest that pupation is occurring in the field.

A yellow beetle with a black head, and square black markings on its back standing on a soybean leaf.

South Dakota Overwintering Bean Leaf Beetle Predicted Mortality: 2024-2025

Each year we evaluate the overwintering success of bean leaf beetles in South Dakota. For adult bean leaf beetles that successfully overwintered, emergence will begin in the spring and they will move into soybean fields.