Content by Philip Rozeboom

Young woman applying insect repellant before an evening hike.

Enjoying the Outdoors Without Tick and Mosquito Bites

Outdoor activities seem extra inviting this time of year, and many people are already enjoying the long days and warmer temperatures. Ticks and mosquitoes share the outdoors with us, but there are things you can do to prevent bites from both.

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

Common Stalk Borer Activity Estimate: June 10, 2021

The hot temperatures last week have resulted in a large increase in degree days for common stalk borer. Common stalk borers should now be scouted for in areas around Hot Springs, Lemmon, Mission, Pierre, Winner, Huron, Mitchell, Tyndall, Sisseton and Vermillion.

Green caterpillar with prolegs at the end of its body that form “V” shape.

Diamondback Moth Caterpillars Active In South Dakota

Diamondback moth caterpillars have been observed in South Dakota gardens. These pests feed primarily on cole crops, such as broccoli, Brussel sprouts, cabbage, cauliflower and kale, leaving behind irregular-shaped holes.

Brown insect with two pincher like appendages at the end of its body.

Earwigs Are Active

Although earwigs typically prefer wet conditions, quite a few have been observed so far this year. It’s important to remember that watering lawns or potted plants around the house provides ideal earwig habitat.

Seecorn maggot larva feeding on a seed in a field.

Seedcorn Maggot Degree Day Activity Estimates: June 3, 2021

We are currently between the second and third generation peak emergences in South Dakota. Seedcorn maggot management must be done before planting, or the populations can be avoided by not planting during times of peak emergence.

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

Alfalfa Weevil Activity Prediction Update: June 3, 2021

It has been a busy week for alfalfa weevils. Throughout the state, alfalfa weevils have been causing significant feeding damage. We recommend scouting alfalfa fields for the next week and treating when necessary.

Aflafla field with light colored alfalfa mixed in with green alfalfa.

Why’s My Alfalfa Field Turning White?

There have been a lot of reports of alfalfa fields in South Dakota with a white or light-brown canopy. This discoloration is the result of extensive alfalfa weevil larvae feeding.

Common Stalk Borer Activity Estimate: June 3, 2021

We still haven’t reached the degree day accumulation levels to see common stalk borers moving into corn fields. However, if weeds and grass are sprayed out along field borders, there is a very high probability that they will be forced into corn early.

Alfalfa Weevil Activity Prediction Update: May 27, 2021

Alfalfa weevil activity is still being reported across much of the state. Although the degree day estimates for South Dakota indicate that much of the state has populations that are pupating, these estimates are not accurate. Scouting should continue throughout South Dakota.

Yellow wireworm on an orange sweet potato.

Wireworms in the Garden

With warming soil temperatures, overwintering wireworms have become active throughout South Dakota. Wireworms are soil-dwelling insects that can be pests of germinating seeds, seedlings and root crops.