After a brief break, cold temperatures have returned to the region. While that might mean you have to turn up the thermostat at home and bundle up before heading outside, a horticulture educator with the University of Illinois Extension said there is a silver lining to the extreme cold.
“Think about all of the bugs that it’s killing right now,” said Chris Enroth.
In particular, invasive insects such as the Japanese beetle are accustomed to milder climates and could struggle to survive during extremely cold conditions, though Enroth said it will take more than a week or two of low temperatures to kill off the pests.
“Right now the Japanese beetles are in their grub stage, they’re living underground. And most of them live in the four-to-six inch layer of soil. They can go up to 10 to 11 inches deep, though.” And he said freezing soil temperatures have yet to reach that deep.
He also said the bugs can super-cool their bodies, allowing them to survive temperatures down to 19 degrees.
“It has to get a little bit colder, and it would be ideal if there was no snow on the ground to allow the soils to freeze much deeper,” Enroth said. He said snow acts like a blanket and prevents the soil from getting as cold as it otherwise would.
But he said it’s a two-edged sword because snow also helps protect some soils, and when snow melts it supplies moisture, which might be needed given how dry it was this past fall.
Enroth said native insects are fairly well adapted to the region’s climate and are less likely to be killed by extremely cold or hot temperatures. And he said cold conditions convince pollinators to remain dormant. He said mild winters can encourage them to emerge and begin foraging when no nectar or pollen is available to help them to survive.