Skip to main content

Plants or Crops

All Plants or Crops Content

Green, teardrop shaped insects on a green leaf that has dark spots. Courtesy: Alton N. Spark Jr., University of Georgia, Bugwood.org.

Low-Level Aphid Populations Present in Wheat

Reports of aphid populations in wheat fields have been slowly increasing in the past week. Most of these populations are well below the economic threshold, but there is a potential for them to increase.

Red-brown colored weevil with bent antennae originating on the elongated mouthparts.

It’s Time to Start Scouting for Red Sunflower Seed Weevils

In South Dakota, sunflower flowering is getting underway. That means it is time to start scouting fields for red sunflower seed weevils.

Green canola plants infested with false chinch bugs with dying leaves.

False Chinch Bugs Are Active in Canola

We have received reports of false chinch bug populations in canola this week. Heavily infested canola fields will sometimes appear drought stressed, but closer inspection reveals that false chinch bugs are the culprits for the wilting plants.

Green and yellow grasshopper resting on a head of wheat.

Grasshoppers Are Causing Concerns in Close-to-Harvest Winter Wheat

During the end of last week, we received reports of grasshoppers feeding on winter wheat that was close to being ready to harvest. One of the questions with the report was, “What insecticide can be sprayed that won’t delay harvest?”

A pasture containing a mixture of grasses and alfalfa.

Start Scouting for Grasshopper Activity in Crops and Grasslands

Most of Eastern South Dakota is experiencing very low grasshopper populations. However, this is not the case for many areas in Central and Western South Dakota.

Small reddish-orange beetles on a green sunflower bud with a larger grey beetle also present.

Identifying Red and Gray Sunflower Seed Weevils

When scouting sunflower, the most observed weevil is the red sunflower seed weevil. However, there are two species of seed weevils that can be present on sunflower heads in South Dakota.

Numerous grasshoppers feeding on a yellow sunflower head.

Watch Sunflowers for Grasshopper Defoliation and Flower Feeding

Grasshoppers continue to be an issue in some areas of South Dakota. The hotspots seem to be along the Missouri River, but it is a reminder that everyone should be monitoring their crops for grasshopper feeding.

Diseased sunflower head, showing sclerotia bodies that have replaced seeds.

Sclerotinia Concerns in Sunflower

Sclerotinia diseases are a concern in sunflowers, because the fungus can infect the plant through the root, mid-stalk or the head. Wet weather and cool temperatures two-to-three weeks prior to and during flowering favor disease development.

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.

Green bee on yellow flower.

Bees and Other Pollinators Visiting Sunflower

While insecticides are often necessary to reduce pest populations and prevent yield loss in sunflower, it is important to consider the impact they may have on beneficial insects, like bees and other native pollinators.