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Content by Adam Varenhorst

A pasture containing a mixture of grasses and alfalfa.

An identification guide for Alfalfa Insect Pests in South Dakota

Pictorial guide for common insect pests of alfalfa in South Dakota

Green and brown grasshopper with two yellow lines that originate on the head and meet on the abdomen.

Grasshoppers May Be an Issue for Winter Wheat This Fall

Large grasshopper populations have been observed in Central South Dakota. These populations have required management in other crops and should be monitored prior to and during winter wheat planting.

Black, yellow, and brown wasp in a clear container

Huge Wasps on My Tree! No, Those Still Aren’t Murder Hornets.

Another insect that has been mistaken for the Asian giant hornet (also known by its media-popularized name of ‘murder hornet’) is the horntail wasp. Horntail wasps are wood-boring insects that are harmless to humans, as they do not have venom and cannot sting.

Left: Black beetle with a red head on soybean leaf. Right: Green soybean leaf with small holes near the center and edges.

Monitor Soybean for Redheaded Flea Beetle Feeding

An additional soybean defoliator to monitor this week is the redheaded flea beetle. Although these beetles are typically not a serious soybean pest, large populations can result in considerable defoliation.

Small white cylindrical mites on a wheat leaf.

Wheat Streak Mosaic Virus is Prevented Before Planting Winter Wheat

Wheat streak mosaic disease (WSMD) is one of the important diseases in winter wheat and can lead to severe yield losses.

Three bean leaf beetles. From Left: Brown beetle with black spots on a green leaf. Yellow beetle with black spots on a green leaf. Red beetle with black spots on a green leaf.

Bean Leaf Beetles Are Active in Soybean

We have received reports of bean leaf beetles feeding on soybean in a couple different areas of the state. Bean leaf beetles go through two generations each year in South Dakota. Adult bean leaf beetles can vary in color from brown, yellow and orange to red.

Gray beetle with long antennae that are alternating white and black pattern on green leaf petiole.

Will Dectes Stem Borers Be an Issue in 2020?

Every year, there is a risk that sunflower in South Dakota will be infested by Dectes stem borer larvae. At this point in the season, adults are active, and females have likely been laying eggs in sunflower plants.

Gray tear drop shaped bugs feeding on a yellow squash.

Squash Bugs Are Active and Ready to Kill Your Plants

Squash bugs are a headache for gardeners almost every year in South Dakota. As their name implies, squash bugs feed on squash along with many other cucurbits. Injury caused by extensive feeding appears as wilting and may result in the death of infested plants.

Small pale green leafhopper on a green alfalfa leaf.

Potato Leafhoppers in Alfalfa

Potato leafhoppers are a migratory pest that commonly impact alfalfa fields throughout South Dakota. Feeding injury caused by potato leafhoppers resembles drought stress and, if left untreated, can reduce both yield and forage quality.

Cream colored moth with a dark brown band in the middle of its body.

Monitor Sunflower for Banded Sunflower Moth Activity

Banded sunflower moths are active in South Dakota, which means it is time to start scouting sunflowers for their eggs. Banded sunflower moth caterpillars can reduce yields and oil content by feeding on the developing florets and tunneling into developing seeds.