Diseases & Disorders

All Diseases & Disorders Content

ash leaves with orange to yellow gall-like spots

Tree Rust Diseases

Ash rust and crown rust are two common rust diseases that impact South Dakota trees.

Two side-by-side grape diseases. Left: Black Rot. Right: Downy Mildew.

Black Rot & Downy Mildew: Two diseases that can rot grapes

There are several different diseases that can infect the fruit, but two of the most common are black rot and downy mildew. Their symptoms are quite different.

hand holding grape leaf with several bumps throughout

Phylloxera: A Grape Pest

Some grape growers may notice that some of their shoots have bumpy growths on the bottom of new leaves. These bumps are galls caused by the grape phylloxera, an aphid-like insect.

closeup of a pig's face, focused on its eyes

Swine Respiratory Health: Detecting Multiple Viruses

Over the past decade, surveillance and diagnosis of respiratory agents have been revolutionized by the use of non-invasive techniques such as oral fluids sampling.

West Nile in South Dakota: Expect Cases Into Early Fall

While it’s true that in South Dakota most West Nile Virus cases occur during August, new human infections are detected well into September in most years.

Two dairy calves in a small pen wearing warming jackets.

Dairy Calf Respiratory Disease: Treatment in the Aftermath of Cold Weather

Cold weather is not just hard on the people taking care of animals, it can be tough on the animals themselves. Consider respiratory disease (pneumonia) in dairy calves.

Sawyer Beetles and Pine Wilt Disease

A sample came in from a recently felled Scotch pine tree down in Southeastern South Dakota. The hole and sawdust is due to a sawyer beetle that had infested the tree.

A cluster of yellow flowers with a large patch of green, wilting flowers on the right.

Fall Yard and Garden Cleanup

Before the snow falls, a few tasks can help make for a healthier yard and garden next year.

An ash tree branch with ash flower gall damage.

Ash flower galls are appearing on the twigs of ash throughout the state. The brown to black “balls” hang in clusters beneath the branch shoots. The galls are due to the feeding activity of the ash flower gall mite (Eriophyes fraxiniflora) and this mite only feeds on the male flowers of ash.

Aphids On Trees

Aphids are appearing on many trees at this time of year and their activity is generally noticed by the abundance of honeydew they excrete on the lower leaves and any plants or objects beneath the tree.