Purdue University Extension entomologist Christian Krupke says farmers who were hoping that western bean cutworms didn’t survive the winter are probably going to be disappointed.
“And that’s not because of the temperature of the air, it’s more because we had so much snow, especially in those northwestern Indiana counties,” said Krupke. “And that snow of course creates insulation on the fields, keeps the soil temperature higher than it would be if there were bare soil and actually helps the larvae to survive, so we would not anticipate a lot of winter mortality.”
Krupke says that means growers should plan now to scout fields during moth flight in the late June, early July timeframe.
“That’s when the moths are flying, mating and laying eggs,” Krupke said. “Scouting is usually very effective if it’s done at the appropriate time and we like to recommend a threshold of 5 percent, so if you scout twenty plants and you see an egg on just one of them, you’re over threshold and you’re going to want to treat with an insecticide.”