 Hello, my name is Jan Knudel. I'm the Extension Entomologist for North Dakota State University. And we're here today in the soybean field to scout for soybean aphids. Soybean aphid was introduced into the United States in 2000, and it quickly spread throughout the north-central soybean-producing states. It was found in North Dakota in 2001, and since then it's been a major pest of soybeans in North Dakota. A critical component of an IPM integrated pest management program is scouting. And with aphids it's particularly important because the populations fluctuate year to year. Some years are bad aphid years and other years are not. So scouting is especially critical for this insect pest. Part of the reason is we have aphids that migrate up into North Dakota from the southern states and also the population levels vary year to year within the state because the eggs overwinter on the buckthorn. And also it has multiple generations up to 15 or more generations per year so the populations can fluctuate. For scouting you want to conduct a V or a W pattern and walk throughout the field. In general you want to sample 38 plants per 50 acres of soybeans. This is our first spot where we're going to sample for soybean aphids. You start by looking at the bottom of the plant looking for the aphids and you need to be able to identify the aphids. They're a small yellow aphid with black cornicles or tailpipes. They're about one sixteenth of an inch long. They may be winged or wingless. Because they're so small you can estimate the number of aphids once you have an idea of how many aphids look like for 10 aphids, 50 aphids, and 100 aphids per leaf and then you can estimate them. And moving up the plant as you're sampling aphids are often concentrated on the upper leaves of the plant. When counting aphids avoid counting the white caskins of the aphids and only count the yellow alive aphids for estimating your numbers. Another thing to note in the field is honeydew. You can see the glossy material and that's all honeydew extract that the aphids excrete. You can look for any predators such as this lady beetle larvae that feeds on the aphids. Other predators of the soybean aphids besides the lady beetle predator include surfid flies and larvae of the green and brown lace wings. For sampling begin when the crop is in the late vegetative stage. Typically in North Dakota that's mid to late June and then continue sampling all the way up through our five. Which is the early seed set. Aphids can occur in hot spots but treatment decisions should be based on a broad sample randomly selected plants. Use the action threshold of 250 aphids per plant. 80% of the plants in the field infested and when populations are actively increasing. This has a built in window to arrange for a foliar insecticide treatment. It's about one week long. With a high market value we recommend that you cut that interval in half three to four days. Once the soybean reaches the full seed set R6 research has not shown a reliable yield gain from an insecticide treatment. Conditions that favor aphid population growth are cool temperatures high 70s to low 80s. Plant stress like drought stress and the lack of aphid predators. For insecticide selections please see the North Dakota field crop insect management guide and be aware if you have spider mites in the field only certain insecticides will control spider mites and soybean aphid. Thanks for learning how to scout for soybean aphids today.