Picture the scene: A bitterly cold, winter day. Grey skies, with cutting winds blowing the snow into deep, waist-high drifts. I’m standing on the porch, shivering, with my two, very young children, who don’t seem to mind the cold.
My daughter asks, “Daddy, where do all the bugs go in winter?”
“They die” replies my son, with a certainty that was admirable, but misplaced. “No,” my daughter came back, “Now I remember. They migrate.”
I had to explain that they were both right, and wrong. Which, I confess, defies the laws of logic, but there you are.
I remembered their questions the other day and it occurred to me that the answer to their question ̶ Where do bugs go in winter? ̶ might actually be important. It is.
Do Bugs and Insects Survive the Winter?
Generally speaking, insects are better able to survive winter weather if temperatures are relatively constant and don’t careen between extreme highs and lows. Many insects find refuge ̶ and sustenance ̶ in an assortment of micro-habitats. These havens can be beneath the soil, inside logs and trees, or in certain plants. Layers of snow can also help insects by insulating them underground.
According to Dr. Scott Hayward, a lecturer in molecular ecophysiology at the University of Birmingham in the UK, insects make it through the winter because, "The vast majority actually becomes dormant."
Dormancy (or diapause) in the long, cold months
This particular form of dormancy is called diapause, which is defined as, "an inactive state of arrested development:"
The shorter days of fall trigger insects to enter diapause. During diapause
an insect's metabolic rate drops to one tenth or less, so it can use stored body fat to
survive winter. Also, many insects produce alcohols for antifreeze. Their bodies can
supercool (reach temperatures below freezing) without forming cell-damaging ice.
Insects' survival techniques vary, depending on what kind of bugs they are and their state of development. For example, some insects survive the winter as larvae (such as the woolly bear caterpillar or turf feeding grubs), either protected by heavy leaf cover or replacing the water in their bodies with glycerol, the organic equivalent of antifreeze! Others escape the cold by burrowing deep into the soil to escape the freezing temperatures.
Some insects ̶ such as the praying mantis and corn rootworms ̶ survive as eggs, while others overwinter as nymphs. Dragonfly, mayfly and stonefly nymphs, for instance, endure in ponds and streams, often beneath ice. They grow all winter and emerge as adults in early spring.
Yet others, such as the moths in the silkworm family, go through the winter as pupae, as do cecropia moths and swallow tail butterflies. They too emerge as adults in the spring.
Forget Bugs. What about Pests?
But...can you get bed bug bites in the winter?
What happens to those pests whose habits and ‘lifestyles’ have graced the pages of these blogs over the years? I mean, of course, such annoying bugs as bed bugs, mites, ticks, fleas and the like.
Unfortunately, bed bugs don’t become dormant in the winter. But this isn’t because they are some sort of super bug that can withstand cold temperatures! Bed bugs don’t become inactive because they prefer to live and breed in homes (and offices) which usually boast the kinds of warm, unvarying temperatures they prefer. More important, perhaps, is the fact that they have easy access to their main source of food ̶ us!
That, combined with a protected environment, means that bed bugs rarely have to undergo diapause to survive. However, it has been shown that bed bugs do not function well in temperatures lower than 60° Fahrenheit or so. Then they can become dormant, surviving up to a year without food.
Alas, the same is generally true of mites, Extreme heat or cold will kill them, but since they live in a variety of habitats ̶ including our homes and offices ̶ they are very difficult to eliminate.
If you do have them in your home, here are some tips for getting rid of bed bugs.
What about Ticks: Where Do They Winter?
Now, you would think that ticks ̶ which usually prefer the outdoors as their regular habitat ̶ would succumb quickly during winter weather, right? Wrong! Ticks are just as resilient as bed bugs, although they use a variety of means to survive the cold weather.
Strategy #1 is to find a ready host and stay attached.
Strategy #2 is to go dormant and hide in the woods and bushy areas that generally call home. Abandoned birds’ nests, woodland debris and leaf litter make for ready hideaways, for instance. And again, snow only serves as an effective, efficient insulating agent.
Which Insects Migrate in the Winter?
My daughter was right in one respect: some insect species do migrate in the winter, the most famous being the monarch butterfly. Chances are that you’ve seen them ̶ in your garden, in a park, perhaps in the woods. Their wings sport an unmistakable black, orange, and white configuration that’s hard to miss.
To quote Wikipedia: “The monarch in North America migrates from as far north as Canada southward to Mexico and Southern California annually from about August to October.”
However, unlike migrating birds, which fly South at the onset of winter, then return when the weather improves, the trip for the Monarch Butterfly is strictly a one-way affair! They lay their eggs all along their southern migration routes, and it is this new generation that makes its way back North at the end of the breeding season.
So, as you can see, insects have developed a variety of ingenious ̶ and for the most part, effective ̶ means of surviving those long winter days.
What about Bees and Ants?
I haven’t mentioned the survival techniques deployed by the many species of ants that make their home in the Lower 48, nor have I said anything about my favorite insect, the honey bee. Both bees and ants are fascinating creatures and deserve an entire blog to themselves. However, for our purposes we will have to limit what we say.
A look at how bees stay warm all winter
Honey bees are truly remarkable insects whose ingenuity and, yes, intelligence, is often underestimated. In the cold, winter months, they behave differently from many other insects: They neither hibernate, nor migrate. If the temperature in your area stays above 50 degrees Fahrenheit, you will probably see them flying around. But once the temperature dips permanently they retreat to their nests, where they remain safely ensconced all winter long.
However, honey bees do not ‘heat’ their hives, as commonly believed. Their response to the cold is altogether more ingenious: They gather in a ‘Winter Cluster,' where an entire hive huddles together and, by vibrating their bodies and wings, produce more than enough heat to survive. In fact, with the precious queen sitting at the center of this cluster, the worker bees are able to generate temperatures of 80 degrees Fahrenheit!
If you’ve ever seen March of the Penguins, you’ll recall that male penguins incubate the eggs, huddling together for warmth in temperatures that can fall as low as minus 80 degrees Fahrenheit. Like the penguins, honey bees regularly rotate their positions from the center to the edge, then back again to the center of the ‘huddle.’ The temperature at the edge hovers around 45-48 degrees Fahrenheit, but at least every single bee gets to share the collective warmth. As for food, honey bees have a built in solution! They survive by eating the honey stored within the hive.
Do Ants Also Hibernate?
Honey bees may be my favorite insect, but I also possess a great deal of affection for ants. Now, that may sound silly, but like honey bees they are remarkable creatures who can teach us a lot about the advantages of cooperation and family stability.
Like many insects, ants are exothermic, which means that they are particularly sensitive to changes in temperature. Basically, this means that they can't regulate their own body temperature.
Since winter temperatures tend to slow ants down considerably, they usually try to winter in warm places. Ants have been known to seek shelter under rocks, in decomposing leaves, underneath tree bark or deep undergrounds.
Like many animals, ants consume large quantities of food during the fall and bulk up to stay fed all winter long. Similar to their flying friends, the bees, ants also cluster together to maintain their collective temperature ̶ and, of course, to protect their precious Queen from the rigors of winter.
Insects: Don't Overlook the Little Guy
I dare say that most of us, most of the time, don’t think too much about insects and their ‘role’ in our world. But we should. To begin with, insects are among the most plentiful and diverse animals on the planet. In fact, they make up some 75% of all known animals. We have already cataloged just over one million species of insects and, if our entomologists are to be believed, there may 10 to 30 million more yet to be identified.
Some of those species ̶ cockroaches, bed bugs, mosquitoes, ticks, fleas and so on ̶ justifiably remain on our collective ‘hit list.’ But insects are a vital, indeed irreplaceable, part of our global ecosystem and life without them would simply be impossible. Just think of the crucial role that bees play as pollinators, and it’s easy to see why we value them so much.
Bugs We Love...and Bugs We Don't
It can be hard to understand why we feel so fondly for honey bees and cringe at cockroaches. Logic aside, much of our gut reaction towards bugs and insects has to do with where they're found. A cricket or toad in your lawn can be cute, but less so on your bed.
That being said, some bugs do pose health risks and, sentiments aside - you have to get rid of them. Ticks, mites, scabies and bed bugs, for example, can cause itchy rashes, allergic responses and even diseases like Lyme.
And so, with bug season just around the corner, you may want to read our tips on how to get rid of bugs this spring. Just please don't harm those honey bees!