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Insect & Pests

All Insect & Pests Content

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

Alfalfa Weevil Activity Prediction Update: May 24, 2024

Degree day accumulations continue to estimate alfalfa weevil activity throughout South Dakota. Alfalfa weevil activity is likely greater in southern counties, but alfalfa should continue to be scouted statewide.

Seecorn maggot larva feeding on a seed in a field.

Seedcorn Maggot Degree Day Activity Estimates: May 24, 2024

Parts of South Dakota are currently at, slightly below, or over the 1,080 degree days for the peak second generation emergence of seedcorn maggots.

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

Common Stalk Borer Activity Estimate: May 24, 2024

Throughout South Dakota, common stalk borer caterpillars are still active in alternative weed and grass hosts.

Green corn leaf with ragged holes through-out caused by common stalk borer feeding.

Common Stalk Borers and Why They Matter in Early Season Corn

Based on current degree day accumulations, the common stalk borer caterpillars are developing within weeds and grass hosts. Once the caterpillars outgrow these hosts they will begin moving into corn fields.

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

It’s Time To Start Scouting for Alfalfa Weevils

This week, alfalfa weevil larvae have been spotted in the fields. Routine scouting is the best method to ensure that alfalfa isn’t heavily defiolated by this pest.

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

Common Stalk Borer Activity Estimate: May 16, 2024

Common stalk borer caterpillars are still active in grass and weeds along field edges. Based on recent degree day data throughout the state, no scouting is necessary for common stalk borer activity in fields yet.

Seecorn maggot larva feeding on a seed in a field.

Seedcorn Maggot Degree Day Activity Estimates: May 16, 2024

Based on accumulated degree days, areas in southern South Dakota are approaching the peak emergence period for the second generation of seed corn maggots.

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

Alfalfa Weevil Activity Prediction Update: May 16, 2024

South Dakota finally warmed up and as a result, alfalfa across the state should be scouted for alfalfa weevil larvae.

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

Common Stalk Borer Activity Estimate: May 8, 2024

No scouting is necessary for common stalk borer activity based on current degree days. Across South Dakota, the young common stalk borer caterpillars are active in alternative weed and grass hosts.

A green pasture with patches of bare soil under a blue sky containing several wispy white clouds.

Dying Patches in Your Pasture? Make Sure You Don’t Have White Grubs.

There have been an increasing number of reports of pastures with dead areas showing up this spring. A little digging into these areas has revealed that part of the problem is the presence of true white grubs, which are the larva of June beetles.