Content by Philip Rozeboom
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.
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.
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.
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.
Black Cutworm Caterpillars Are Actively Feeding in South Dakota
We received numerous reports this week of small holes in V1-V2 corn plants. The holes are the result of early instar cutworm caterpillar feeding and, more specifically, black cutworm caterpillars. After hatching, black cutworm caterpillars initially feed on the leaves. As they develop and become larger, they pose a clipping or cutting threat to corn.
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.
Monitor Newly Emerged Corn for Black Cutworm Activity
There are several important insect pests that can severely injure corn during the early vegetative stages. One of these pests is the black cutworm. Although black cutworm caterpillars injure corn by feeding on leaf tissue, the serious damage occurs when caterpillar feeding results in the cutting of young corn plants.
Watch Corn for Bronzed Cutworm Activity
Bronzed cutworms are not a common pest of corn in South Dakota. However, they can become an issue when corn is planted into areas that were previously grassland. Like its name implies, bronze cutworms feed on corn above the soil surface, which often results in cutting or clipping.
Common Stalk Borer Activity Update: May 23, 2019
Not too much is new regarding common stalk borer activity when compared to last week. Another cool, wet week has led to a limited accumulation of degree days. Based on our calculations, common stalk borer activity still doesn’t warrant any scouting. We will continue to monitor the degree days and provide updates.
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.