2019 Weather Impact on 2020 Insect Pressure

This year’s turbulent weather led to an abundance of issues, including planting delays which translated into harvest delays. Unfortunately, later-maturing crops were an open invitation for extended or additional generations of pests in corn and soybean fields. Mike Leetch is the Syngenta agronomy service manager for the western Midwest. He says that certain insects expanded, both in terms of their geographic range and higher-than-normal populations this year.

Leetch shares his insights on this year’s top pests and potential impact on the 2020 crop, starting with the corn crop…

“Probably the most important thing in corn we’ve seen this year is a resurgence in the corn rootworm population. In the western Corn Belt, I can see a lot of corn that has root lodging, and a lot of it could be blamed on rootworm. There’s always a threat of both cutworms and armyworms coming in. All of these pass, but most importantly, focus on the rootworm issues. They can have a significant impact on yield, but then the other component is the impact early rootworm damage larvae feeding has on the harvest ability of our corn crop. It just makes it slow and we lose an awful lot.”

For soybeans, Leetch says many farmers saw issues with the thistle caterpillar…

“They hit hard in July and August. Many farmers saw that rather attractive butterfly out there and they thought, “Well, butterflies are probably good for my crop. That’s a beneficial.” When in fact, they lay an egg and the larvae bores into the plant and then significantly later on, it will destroy the bean in the pod. We also have a couple of pests that are more centered towards the western Corn Belt. The soybean gall midge is one that, it exploded last year in its geographic range in western Iowa, eastern Nebraska, and a little bit of South Dakota, Minnesota. This year, it went farther east, across Iowa and has consumed a lot of southern Minnesota. And then the second one that is expanding that we’ve seen for many years in Kansas and Nebraska is Dectes stem borer. Growers need to pay attention to those if you live east, because those populations are moving.”

The good news is Syngenta offers solutions for numerous pests so growers can effectively manage them in 2020. Leetch says it’s important for growers to take an integrated approach to pest management…

“Scouting and knowing what’s going on in the field is absolutely the first premise to good management. And then monitoring the populations. So when we’re addressing the rootworm issue, the first and easy button is to use a traited corn rootworm hybrid. But even in the worst-case scenario, a product like Force®, a soil applied at planting product with your corn, is going to be the best protection against high populations, even with a traited corn product. Now, of course with cutworms or armyworms, Syngenta has a full range of insecticides that are excellent performers in terms of knocking those populations down. The most common for either one would be either Besiege® insecticide or Endigo® ZC insecticide as a foliar application.”

In soybeans, he explains what options growers have…

“Besiege® insecticide or Endigo® insecticide are going to be very good for the thistle caterpillar. It’s very quick knock-down and long residual from either one of those products.Now, with soybean gall midge, I have to stop and say we really don’t have a good solution for growers at this point. Dectes stem borer, we still have a lot to learn on that one in the soybean, but a foliar application when the adult emerges and begins laying eggs is the best management tool, but it’s difficult to estimate when that timing is. So it is still a challenge, and I’ll just assure the listeners that not only Syngenta, but across the industry on Dectes stem borer and soybean gall midge, we are putting a lot of research emphasis in trying to find a solution.”

To learn more about how to manage insect pressure from 2019 going into 2020, check out the Syngenta agronomy blog at www.KnowMoreGrowMore.com. For more information on Syngenta products, visit www.SyngentaUS.com or talk to yo ur local Syngenta dealer. Always read and follow label instructions. Besiege, Engido ZC, Force, Force 3G, Force 6.5G, Force CS and Force Evo are Restricted Use Pesticides.