Does Cold Weather Really Kill Bugs?

January 8, 2018By

For most of us in southern Louisiana, winter is more than a respite from the heat. It’s a chance for plants to renew their strength, and for living things to slow down and rest. It also supposedly marks a time of the year when insects go dormant, and if the temperature drops low enough, die off.

However, emerging science is calling this assumption into question.

Does cold weather really kill off bugs?

Formosan termites hibernate underground

Maybe, but Maybe Not

Between polar vortices and arctic cold fronts, it seems like anything that might have to live outdoors during the winter will have a tough time surviving. That would seem to imply that many insects will die off during this time of year, but the truth is that this doesn’t really work that way. All insects have some degree of cold tolerance, and all of them have strategies they can employ to give themselves the best possible chance for survival.

In order to really kill off those pests, you need deep-freeze like temperatures. When the mercury doesn’t plummet that low, it doesn’t really phase them.

In fact, because of warmer than average temperatures for the past several years, the deer tick, infamous carrier of Lyme disease, is now found farther north than ever before.

Some Do Die

Some insects do die with the onset of winter. Field crickets are good examples. They have very little cold tolerance, and will usually die off with the first hard frost. However, there’s a catch – they’re designed by Mother Nature this way, which means they spend the weeks before winter descends laying eggs to ensure the continuation of their line.

Even insects that don’t survive cold temperatures lay eggs that overwinter just fine in most cases. When the weather warms up, the eggs hatch, and the next generation begins.

It Needs to Be REALLY Cold

The assumption that temperatures falling below the 32-degree F mark mean death to bugs is sadly mistaken. While cold weather can and does kill bugs, it needs to be really, really cold. In fact, if temperatures don’t drop below 0 degrees F, many insects are totally fine.

Even when temperatures do reach the 0-degree mark, many insects are not all that perturbed. For instance, the emerald ash borer, the infamous architect of pine tree destruction across the US, can withstand cold of up to -20 F.

Termites fall into the category – not because they have any innate resistance to the cold, but because they live in a protected environment (underground, or within a tree, or even in your home), so freezing temperatures have very little effect on them, or other colony insects, including bees and ants.

Other Strategies to Survive

As mentioned, many insects have ways to survive the winter. Some burrow into the ground. Some already live primarily underground, like Formosan termites. Others move into your home with you and your family – stink bugs and ladybugs are probably the two most visible examples, but there are plenty of others.

Spiders regularly move into homes during the winter, and then back out again when the weather warms up a bit.

Other insects don’t need to worry about finding a new home. They go into hibernation where they live now. During this time, the insects need little or no food, and can survive very cold temperatures.
Ultimately, cold weather is not a good indicator of the year to come, at least in terms of insect life. Neither is warm weather, as it can encourage insects to emerge early, before their food source is active, and then they starve. For homeowners, the best defense is to stay vigilant, and ensure that you have proactive help from a trusted pest control company.

Filed in: Bugs