A little snow won’t stop insects with spring fever
When you’re a little guy looking for love, you have to bid adieu to home, writes TOM SPEARS.
Insects are awake as winter ends, a whole landscape of them crawling around in the March snow, mostly looking for love.
This is mating time for snow fleas, snow flies and snow scorpions, all insects that contain enough natural antifreeze to be active at several degrees below zero.
They are little dark specks on the surface of snow — like flecks of dirt just a couple of millimetres long, a Carleton University biologist says, “except these ones move.”
Late winter is when they come to the surface, protected against freezing by antifreeze they make themselves.
“They’re around yearround, but in the case of snow flies they live as larvae most of the year,” said Carleton’s Mike Runtz.
The larval period is an immature stage when they live in mouse burrows, eating the mouse droppings.
That keeps them warm all winter. But late in the season they pop up to the surface, even though it’s colder above ground. A theory says leaving home to find a mate avoids inbreeding.
They’re visible “especially on overcast days in the afternoon. They’re active between minus-five and zero degrees Celsius,” Runtz said. “On sunny days, they tend to be active much later in the day, but on cloudy days they’re active all day long.
“These snow flies, when they feel threatened, pull their legs in and just look like a piece of debris on the snow. That’s probably their way of avoiding predation. They sort of play dead.”
Snow fleas are about half the size of snow flies. Properly, they aren’t fleas but collembolans, a group of insects also called springtails because they have a springlike appendage that lets them jump a long way. They have no wings. Last week’s snow wouldn’t bother the snow insects. Runtz said they simply crawl up to the surface as long as it isn’t too cold.
“You rarely, if ever, see one snow flea. You tend to see hundreds, thousands, millions at a time. They can darken the snow like pepper grains.”
pressions such as footprints or ski tracks.
Runtz has never seen a snow scorpion, but looks each year. They aren’t scorpions, but are named for their shape.
“People see them frequently, especially in Gatineau Park on the ski trails, and Algonquin Park,” he said. “I’m determined to find a snow scorpion this spring. I’m glad there’s more snow; it makes it easier to find them.”
But why should insects fight the cold when they could wait for spring weather?
“Because they can do it. Whenever there’s an opening in nature, something takes hold of it.”
All these insects produce glycer- ol, a natural liquid antifreeze once used in cars and still widely used in industry.
It’s a different system from the antifreeze proteins used by cold water fish such as Arctic cod.