Do Freezing Temps Kill Bugs?

By Paul James

In the past few weeks, I’ve repeatedly heard the claim that the recent snap of cold weather means the bugs won’t be bad this year. The idea of course is that bugs can’t survive prolonged cold temperatures and therefore their populations will be greatly reduced if not eliminated entirely. But does that claim have any basis in fact?

Sorry, no. While it’s true that a number of bugs can’t survive freezing temperatures, they’ve developed truly remarkable ways of protecting themselves and furthering their progeny.

The simplest way to beat the cold is to migrate to a warmer spot, just as Monarch butterflies do. Moving into your house is another common means of survival for numerous insects including crickets, ants, ladybugs, stink bugs, moths, and even wasps.

Insects that can’t survive cold temperatures at least know how to sustain their populations by laying eggs underground, in leaf litter or garden refuse, and in buildings.

And what about fleas and ticks and mosquitoes? Again, sorry.

Fleas are clever enough to find ways to stay warm, whether on wild or domesticated animals or in garages, under decks, and around foundations.

Ticks begin a process of acclimation long before winter arrives by moving water out of their cells before it freezes and crystallizes, thereby allowing them to survive freezing temperatures. They also escape the cold beneath leaf litter and other warm spots.

Mosquitoes actually hibernate both inside and out. They also lay eggs in the fall that can survive the cold – even in frozen water -- and remain dormant until spring.

And there are some insects – the Emerald Ash Borer for example, as well as some mosquitoes – that produce a sort of antifreeze in their blood called glycerol, which enables them to survive freezing temperatures in a state of suspended animation. It’s insect cryogenics, basically.

Let’s face it. Insects have been around for millions of years, and rarely do we hear of them becoming extinct. They’ve survived predators, pesticides, an asteroid that killed off the dinosaurs, and yes, even nuclear explosions. Among living things, they are the ultimate survivors.

And you think something like a little cold weather is going to affect them?