News

Corn rootworm populations building

An extension entomologist is seeing northern and western corn rootworm populations build following a mild winter.

Ken Ostlie with the University of Minnesota says many parts of the Corn Belt experienced warmer-than-normal temperatures the first three months of the year, leading to lower pest mortality.

“For the most part, conditions this year have allowed them to lay eggs last fall and survive the winter just fine.  And areas that haven’t had a lot of rainfall, (the corn rootworms) seem to be doing quite well.”

He tells Brownfield this is a prime time to be scouting for adult rootworm beetles.

“The nice thing about scouting corn rootworms (is) it gives you an idea of what you’re going to be facing down the road, as well as kind of a snapshot on how good your management is right now.”

Ostlie says as farmers consider going away from Bt traits to save money, it’s important to evaluate rootworm pressure for future growing seasons.

“This would be one case where a little bit of information can help make those decisions with a little more confidence.”

Brownfield interviewed Ostlie during Minnesota Extension’s Ag Pro Field School last week.