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Content by Philip Rozeboom

Two common caterpillar pests of corn. Top: Corn earworm caterpillar. Bottom: European corn borer.

A Case of Mistaken Caterpillar Identity

Tweets about European corn borer (Ostrinia nubilalis) caterpillars in the stems of conventional corn and feeding in the whorls of corn are crossing my Twitter feed. Unfortunately, there is a problem with some of these tweets. Not all of the caterpillars that are being identified as European corn borer caterpillars are actually European corn borer caterpillars!

Three common soybean defoliating pests. From left: Green cloverworm, grasshopper nymphs, and thistle caterpillar.

Monitor Soybean for Defoliating Insects

While scouting soybean this week I noticed quite a few defoliating insects that were present in the field. So far, the feeding injury is minimal, but it is a reminder that we need to be diligent in monitoring leaves for defoliation and fields for these insect pests.

Green soybean with wilting/dying soybean within the same row.

Soybean Gall Midge Larvae Found in South Dakota

Although we have yet to capture any adult soybean gall midges, the reports and observations of soybean gall midge larvae in soybean are pouring in this week. In Clay and Union counties, infested soybeans are now showing signs, with plants beginning to wilt and die in some cases.

Group of small grey insects with clear wings on green plant.

Monitor Canola Fields for False Chinch Bug Activity

While scouting canola this week, I came across a field that had plants along the edge that looked like they were suffering from drought stress, but given the recent rain I doubted that to be the case. Closer inspection of the stressed plants indicated that they were covered in false chinch bugs. Although false chinch bugs are not normally an issue in canola, very large populations do have the potential to reduce yield.

Top view of a black colored ant inside of a clear plastic container.

Watch Out For Carpenter Ants

With the continued moisture and warmer temperatures, carpenter ants have become a more common appearance in South Dakota. Similar to termites, this insect can be a structural pest, causing damage to homes and other buildings. It is important to identify and treat carpenter ants early to prevent any potential damage.

Black and white county map of South Dakota, Minnesota, Nebraska and Iowa. Red dots within counties indicate soybean gall midge emergence. Black dots represent trap locations.

Soybean Gall Midge Are Emerging Around Us, But No Captures in S.D.

Last year, the soybean gall midge caused a lot of issues in soybean, including lodging and up to 50% yield loss. In an effort to determine when soybean gall midge adults are emerging in 2019, a network of emergence traps has been established in South Dakota, Nebraska, Iowa and Minnesota. So far, emergence of the adult soybean gall midge have been reported from Iowa, Nebraska and Minnesota.

Small black fly.

What Are Those Little Flies That Keep Biting Me?

If you have been swarmed and bitten by small black flies this year, you’re not alone. The culprits of these bites are commonly referred to as black flies or buffalo gnats. The reason we are noticing so many in 2019 is likely due to favorable spring conditions that included a lot of moisture.

United States Environmental Protection Agency logo.

Cancellation of Several Neonicotinoids

On May 20, 2019, the United States Environmental Protection Agency announced the cancellation of registrations for 12 products that contain neonicotinoid insecticides. The cancellation of the product registrations was voluntarily requested by the companies that had registered the products.

Numerous grayish-brown bugs gathering on the stems of a Brassica plant.

False Chinch Bugs in the Garden

Swarms of false chinch bugs have started appearing in South Dakota this month. Although they are typically only a nuisance pest, their populations can become magnified during cool, wet springs (like this year). In high abundances, false chinch bugs can pose a threat to garden plants, especially Brassica plants such as broccoli, cauliflower, turnips, and cabbage.

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.