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Insect & Pests

All Insect & Pests Content

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.

Alfalfa weevil larvae and adult.

Alfalfa Weevils Are Active in Some Parts of South Dakota

Degree day accumulations indicate that alfalfa weevil larvae should be active throughout South Dakota.

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

Alfalfa Weevil Activity Prediction Update: May 22, 2025

Degree day accumulations for alfalfa weevil larvae indicate that third to fourth instar larvae should be active in fields throughout South Dakota.

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

Alfalfa Weevil Activity Prediction Update: June 5, 2024

Although the degree day estimates suggest that alfalfa weevils are no longer active in the fields and should be pupating, scouting has indicated otherwise.

2025 Rangeland Grasshopper Hazard map. Photo Courtesy of USDA APHIS, PPQ.  ALT TEXT: Map of South Dakota of Northern Great Plains and the Western United States. Colors indicate the number of grasshoppers per square yard in each of the sampled locations. For a detailed description, please call SDSU Extension at 605-688-4792.

South Dakota Grasshopper Prediction for 2025

In 2025, it is likely that grasshopper populations will once again reach levels capable of causing issues in some areas of the state. Scouting should begin shortly after planting in areas where they were problematic in 2024 and continue throughout the growing season.

A small black bug with tan margins on its wings resting on a grass seed head.

Black Grass Bug Activity Ramping Up

Black grass bugs feed on fresh green growth, which can result in stunted plants and decreased forage quality. Monitoring and potential management of black grass bugs will be of increased importance this spring, especially if drought persists.

Four common South Dakota ticks: American dog, Rocky Mountain wood, blacklegged and Lonestar.

Spring is here, and so are the ticks!

As spring continues to bloom, more arthropods will begin to emerge from winter dormancy. Ticks are among the first to appear, and statewide reports have already been flowing in.

A male and femail dung beetle rolling a ball of dung in a pasture. Courtesy: Beverly Skinner/USFWS (CC BY 2.0)

Managing Livestock for Dung Beetles and Other Beneficial Species

South Dakota researchers have taken a closer look at the function of dung beetles in Eastern South Dakota over the last few years. This article summarizes findings related to management of livestock grazing and chemical pesticides in relation to dung beetle and insect community health.

Three grassland insects. From left: white grub, dung beetles and Dakota Skipper Butterfly.

Rangeland Insects Are Critical Indicators of System Health

Insects, in general, may offer more indication of rangeland health than any other type of organism. They serve as key building blocks that other organisms depend on.

Monarch butterfly collecting pollen on a blazing star plant.

Understanding the Critical Role of Broadleaf Pollinator Plants in Pastures

Understanding the economic role of pollinators is the first step towards understanding their value to grassland and crop systems.