Thoughts on Controlling Insects & Future Perils
Farmers around the world have had it pretty darned good for the last couple of decades as it comes to dealing with insects. That’s changing.
Generally, the insects that have done the most damage to crops, especially to corn in the Midwest, have been suppressed by genetic modifications to the plant. The first of these GMOs was released in the mid-1990s and aimed to control the European corn borer. The Bt modification within the plant is termed a high-dose event and it has been really, really effective says University of Illinois Extension Entomologist Nick Seiter.
“That’s an insect that has been controlled by Bt crops for such a long time that we really do not deal with that insect in close to the same degree as was once the case. The other really neat thing about that insect is that we’ve had the same controls available for it for 25 years without any resistance development in the United States and that never happens. I cannot think of another example of something that has been that widely used for that long without resistance development in a major pest.”
Again, the Bt genetic modification used to control the European corn borer is a high-dose event designed to kill all European corn borers feeding on the plant. The genetic modification to control the western corn rootworm is a low dose event. It’s first introduction came in the early 2000s and land grant entomologists were not convinced it would be durable. They were right.
“We are running out of these products, whether it is Bt traits or even to our west – insecticides out in Nebraska – we are running out of products at a time that we are not really developing new products. At least not fast enough to keep up with that. You could think of it as the same situation we have with herbicide-resistant weeds right now. We are a few years behind that but we are on the same path.”
It is a path Seiter says which needs to be blocked. It means changing how the western corn rootworm is managed by introducing more variability and rotation into the management scheme.
“Because if we rely on the same management scheme year-after-year we know exactly where that is going to get us.”
The result will be western corn rootworms that are resistant to all available control methods.