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Content by Adam Varenhorst

Young corn emerging in a no-till field.

Estimating Corn Emergence With Growing Degree Days: Data from May 7, 2021

With corn planting well underway in South Dakota, the next step is monitoring its emergence. One of the factors that can speed up or delay corn emergence is air temperature.

Two photos of alfalfa weevils during different lifecycle stages. The left is the larva stage and has a longate, green larvae that looks like a caterpillar with white stripe running down the body and brown h

Alfalfa Weevils Are Active, and It’s Time to Scout

Scouting and managing alfalfa weevils when they reach the determined thresholds can prevent yield loss and encourage healthy regrowth of infested alfalfa stands.

Green beetle larvae with a white stripe running down its body.

Alfalfa Weevil Activity Prediction Update: May 13, 2021

Although last week was warmer, we still didn’t accumulate a lot of degree days for alfalfa weevils. However, the upcoming forecast looks more favorable for alfalfa growth and alfalfa weevil development.

Purple-brown caterpillar with orange head on a green corn leaf.

Common Stalk Borer Activity Estimate: May 13, 2021

The upcoming weather forecast looks warmer than the last few weeks, and that means we will begin to accumulate degree days for the common stalk borer at an increased rate.

Numerous small black beetles feeding on a green leaf.

Flea Beetles Already Active In Gardens

It may seem early, but flea beetles are already active in gardens in South Dakota. Adult beetles feed on leaves and stems, and their feeding will leave behind a multitude of small, irregular holes or pits.

Winter wheat plants at the tillering growth stage with leaves yellowing as a result of wheat streak mosaic virus infection.

Wheat Streak Mosaic Developing in Winter Wheat Fields

A few winter wheat fields in central South Dakota have been found with wheat streak mosaic disease. Incidence of this disease varied from a few plants to large portions of the field with yellowing leaves.

A small black bug with tan margins on the wings. This insect is resting on a grass seed head.

Drought Conditions Magnifying Impact of Black Grass Bugs

With much of South Dakota continuing to experience moderate-to-extreme drought conditions, black grass bugs could become a concern in some areas. Large populations of black grass bugs can cause severe damage to pasture.

Top: Army cutworm caterpillar. Bottom: Pale western cutworm caterpillar.

Monitor Wheat for Early-Season Cutworm Activity

It's finally warming up in South Dakota, and insect activity in wheat fields will be increasing. For wheat, a couple of early-season pests that may already be active are the army cutworm and the pale western cutworm.

Grain bin fan with a plywood cover installed on the exterior.

Check Your Bins This Spring

As it warms up this spring, don’t forget to check the bins. Grain bins work as solar heat collectors, and the grain inside of them may be much warmer than expected.

Green beetle larvae with a white stripe running down its body.

Alfalfa Weevil Activity Prediction Update: April 29, 2021

With another warmer week in the forecast, the need to scout for alfalfa weevils continues. Based on current degree day accumulations, overwintering alfalfa weevil adult activity is likely throughout all of South Dakota.