In most parts of the world, winter cold is downright dangerous for humans.
Temperatures as high as 50 degrees Fahrenheit can leave you in a hypothermic state if you’re wet and unprotected, and once it’s around minus 30 degrees a healthy person wandering around would be dead in around 10 minutes without some exceptional survival gear.
Curled up and warm by the fire and/or heating vent, it’s hard to imagine any creature having a life cycle that not only involves living in cold and freezing temperatures, but relies on them to properly survive. Many insects live such frigid existences, braving the cold in a variety of forms between larva and adult.
While it may seem that winter landscapes are completely devoid of insect life, in fact most local insects take shelter in plain sight during the colder months.
Insects are able to survive long periods of low temperatures and rare to nonexistent food and water. Many insects have a period in their life cycle that excels at winter survival.
The habitat necessary for insects to wait out the winter is pretty simple – loose bark, fallen and/or hollow trees and thick leaf litter or mulch all serve as insect bungalows.
Hollows in large fallen logs can stay quite warm compared to the outside world, and are home to hundreds if not thousands of bees, wasps, butterflies and other beneficial wildlife all huddled together until spring.
A good many local insects wait out the winter as an egg or young immature form, using a layer of leaf litter, soil and/or special adaptations to help them survive.
Some worms, for example, leave eggs in the top layers of soil that hatch in early spring. Like migrating birds, a few insects use the mobility of their adult forms to simply run from the cold, as in the case of monarch butterflies who travel thousands of miles each year.
Most don’t have that luxury, and rely on controlling how their body freezes in extreme temperatures. Many insects actually find a way to either prevent their bodies from freezing entirely or they control exactly where they freeze, sacrificing sections of their body.
This is accomplished by distributing sugars and other substances throughout their bodies, and in some cases also dehydrating their cells, turning themselves into insect mummies. Many of these animals enter a state called diapause, which is like hibernation but the participant is sometimes also semi-frozen.
Many of our native solitary bees, which only live for a few frenzied weeks in their adult forms, mature for almost a year in their young and pupal states, relying on similar adaptations along with specialized cocoons to weather the elements.
Avoid cutting down or pruning any trees or shrubs in the winter, as beneficial insects could be sheltered in their branches and trunks, especially underneath loose bark or inside of hollows. I tend to let most of my plants stand for the winter, and cut perennial wildflower stalks in early spring.
Some insects use pithy stems and the base of grass tufts for nests, so leave anything with hollow stems to at least a foot when trimming. Leaf piles, thick mulch and other similar locations are important overwintering sites for insects, especially bumble bee and wasp queens. Try and establish an area that is always covered by at least a few inches of leaves throughout the year. Don’t pile your leaves right at a woodland edge – instead try and have them either included in your garden designs or farther into the forest. Maintaining these overwintering sites will help your local insects and other beneficial wildlife settle down for the long haul.
Brannen Basham and his wife, Jill Jacobs, operate Spriggly’s Beescaping, a business dedicated to the preservation of pollinators. He can be reached at email@example.com.