Insect & Pests

All Insect & Pests Content

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

Common Stalk Borer Activity Estimate: May 6, 2021

We are beginning to accumulate degree days a little faster for common stalk borers. Eggs will be hatching through much of the state, and we will continue to monitor activity as the season progresses.

Green corn leaf with common stalk borer caterpillar within.

Common Stalk Borer Activity Update: June 6, 2019

It finally warmed up and the insects have definitely become more active. However, our calculations indicate that not enough degree days have been accumulated for common stalk borer activity to warrant any scouting, but spraying field edges should be avoided through most of South Dakota in the next week.

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

Common Stalk Borer Activity Update: May 30, 2019

Another cool, wet week has led to a limited accumulation of degree days. Based on our calculations, common stalk borer activity still doesn’t warrant any scouting, but spraying field edges should be avoided around Hot Springs, Winner and Vermillion.

Green corn leaf with common stalk borer caterpillar within.

Common Stalk Borer Activity Update: May 23, 2019

Not too much is new regarding common stalk borer activity when compared to last week. Another cool, wet week has led to a limited accumulation of degree days. Based on our calculations, common stalk borer activity still doesn’t warrant any scouting. We will continue to monitor the degree days and provide updates.

Green corn leaf with common stalk borer caterpillar within.

Common Stalk Borer Activity Update: May 16, 2019

The hatching and movement of common stalk borer caterpillars can be estimated by using degree days with a developmental threshold of 41 degrees Fahrenheit. Common stalk borer eggs typically begin to hatch at 575 degree days.

White butterfly with black markings on wings, resting on a green leaf.

Cabbage White Butterflies Are Here!

Keep an eye out for cabbage white butterflies in your garden. These butterflies lay eggs on the underside of the vegetable leaves. Once the eggs hatch, their caterpillars feed on cabbage, broccoli, Brussel sprouts, cauliflower, kale, turnips and radishes.

Two, dark green aphids on a bright green leaf.

Small Aphid Populations Observed in Wheat

This week we received the first report of aphids in wheat for the 2021 season. The populations won’t be increasing rapidly until the daily temperatures warm up, but it is still a good idea to scout fields and determine if aphids are present.

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.

A grub that has an orange colored head and legs and a white body with a dark grey tip at the end. The grub is laying on top of the soil.

Do You Have Grubs in Your Lawn?

We’ve had quite a few calls about dead patches in lawns this spring, which could be a sign of grub activity. If areas of your lawn are not greening up or appear to be dying, it is important to scout to determine if grubs are present.