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Crop Management

All Crop Management Content

Small black and yellow beetle feeding on the green leaf of a canola plant.

Flea Beetles Defoliating Canola in South Dakota

This year flea beetle emergence is behind schedule, but so is a lot of the canola emergence. We are observing very large flea beetle populations on late-planted canola that is just emerging. As a result, much of this canola is being heavily defoliated and will likely require foliar insecticide management.

Three types of plant bugs. From left: Meadow plant bug, Lygus bug, and alfalfa plant bug.

Plant Bugs Showing Up in Alfalfa Fields

Plant bugs are now becoming active in alfalfa fields across the state. A common question we receive is why some of these bugs looks so different from others. There are actually three different types of plant bugs that commonly appear in alfalfa fields: meadow plant bugs, Lygus bugs (aka tarnished plant bugs), and alfalfa plant bugs.

Green beetle larvae with white stripe and brown head.

Alfalfa Weevil Activity: June 7, 2019

Quite a few degree days were accumulated over the course of the last week. Alfalfa fields should be closely monitored for alfalfa weevil activity for the next couple of weeks, even in areas where degree days indicate the alfalfa weevils are pupating.

Teardrop shaped green insect with long legs and antennae on a lighter green leaf.

Pea Aphid Populations Increasing in Alfalfa

While scouting alfalfa this week, we noticed pea aphid populations are starting to increase. The forecast is looking favorable for this pest, so it will be important to continue monitoring populations prior to and after the first cutting.

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

Alfalfa Weevil Activity Update: May 30, 2019

It was another cool week for most of South Dakota, with little degree day accumulation occurring. However, alfalfa fields should still be monitored for alfalfa weevil activity, although the cool, wet weather might have slowed the pest down.

Brown beetle with long snout.

2019 Alfalfa Weevil Activity

It was another cool week in South Dakota with not a lot of degree day accumulation occurring. Alfalfa fields should still be monitored for alfalfa weevil activity even though the cool wet weather might have slowed this pest down.

Sun rising over a vast spring landscape with green corn emerging from the soil.

Large Farms More Dominant in South Dakota Crop Production

Large farms play a more dominant role in South Dakota crop production, according to the recently released 2017 U.S. Census of Agriculture. As of 2017, large farms of more than 2,000 acres operate 66.8% of South Dakota total cropland aces compared to 47.7% as of 1997.

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

2019 Alfalfa Weevil Activity Prediction

One of the major insect pests of alfalfa in South Dakota is the alfalfa weevil. In 2018, we received fewer reports of alfalfa weevils, which may have been a result of the cooler and wetter spring conditions. It’s possible that populations may also be lower in 2019 due to the similar spring conditions that we are currently experiencing.

grasshopper sitting on plant leaf

Grasshopper Mites in South Dakota

Fact sheet that covers the ectoparasite grasshopper mites.

Two weevil larva. Top: alfalfa weevil. Bottom: clover leaf weevil.

How to Differentiate Alfalfa Weevils From Clover Weevils

When scouting alfalfa, there are two species of weevils that are commonly observed. They are the alfalfa weevil and the clover leaf weevil. Although they are similar in size and coloration, each species has unique characteristics that can be used to identify them.