What you need to know about soybean midge

With the harvest fast approaching, it's easy to become complacent with crop screening. The soybean midge, a relatively new pest problem, proves that screening is essential until combinations are in the field.

Shortly after July 4th, Wayne Miller, a farmer in Shelby, Iowa, began to have plants on the edge of dying fields. He asked a drone to look for green corn and noticed another soybean field with significant damage. With his seed merchant, they began to investigate what was causing the damage. Miller discovered that he had a soy midge after being led by Allison Roberts, a phytopathologist from the State University of Iowa.

The soybean midge, also called orange midge, crosses the corn belt, which is now found in Nebraska, Iowa, South Dakota and Minnesota. Here's what you need to know:

How is soy cider spread? "The fly comes in and he lays the eggs in the stalks just above the ground," explained Miller to the AgriTalk Chip Flory host. "Then this eventually turned into larva and apparently they only eat one free meal. Then, finally, they come back to the fly and the cycle repeats itself again. "

What does the larva look like? "The kids they started are almost clear and very short," Miller said. "It's hard to see them with the naked eye." Then, as the larva ages, it turns pink, then dark orange or red, but it's still quite short . "When you find as much as I've seen in some of my booths a month ago, we can have up to 40 in a rod," Miller said. "It's pretty disgusting to see that."

What is soy cider for plants? The fly lays eggs in the stem of the plant. "Often we find a pin stitch. And I guess we're assuming it's where the fly has laid the eggs, "Miller explained. "Then it is there that the bile is formed. It is essentially an enlarged part of this stem that is caused by the change of hormones in this plant. As the [larva] continue to eat in there, it just suffocates the traffic that goes up and down the stem. And above this gall, the plants will die. It's a pretty fast process, especially the numbers we see.

How can you find it? Scouting is the only way to find this pest. At some point, the plants will die, so it is not uncommon to see dead soybeans at the edge of fields that have this problem. However, at first they look good. "The bad side is that even seemingly healthy plants, they can look great, but you can take your hand and slip through and you just hear them snapping," explained Miller. "You inspect these plants and guess what? They also have the damage. "

How widespread is this pest? Soybean midge has been observed in Nebraska, South Dakota, Iowa and Minnesota. On Miller's farm, the damage began in 10-foot strips on the edges of the fields, but recently, he noticed windrows from 60 to 80 feet at nearly 100% of the midge's loss of life. "I'm not talking about a small area and I may be talking about half a kilometer long, and then it's going down toward the center of the field," Miller said.

Can it be treated? Since adult flies do not eat, they only breed on animals whose residual chemical control is very difficult. He says this pest will be treated systemically, but there is no control method at this stage. "We signed with Iowa State [to do] some tests in depth next year, "he said. "We will try to get a maximum rate on a seed insecticide, hoping we can move fairly quickly."

For more information, visit the Crop News blog of the University of Minnesota Extension here.