One thing many people look forward to as the weather cools off is less pests! But where do they go? Do they really die off? Well… some do and some don’t. All insects have some ability to withstand cold weather, some just do it better than others. In fact, in areas with warmer climates where there isn’t a true deep freeze, some populations go completely unscathed and explode in the springtime. The lower the temperatures drop, the fewer pests survive. The actual temperature to kill off pests varies by species with some able to survive as low as -20 degrees Fahrenheit, while others (like fleas) only able to last until 37 degrees.
When winter comes, pests have a few options about how to survive the cold weather. Some species die off completely, leaving eggs to hatch in the spring to continue the population. Some bury themselves, either underground, under leaf litter, or even under tree bark. Temperatures are usually warmer underneath the surface so they have a better chance of surviving here. Other pests will congregate in natural structures (think bees in a beehive or ants in a pine tree stump). These creatures will huddle together for warmth until the spring thaw. Another option is migration like the monarch butterfly where they make their way to warmer climates for the winter and then return home in the spring. Lots of species go into a state of either diapause or hibernation where their metabolic activity slows down but they don’t die off. They then remerge when warmer temperatures kickstart their systems again. The last option, and the one that affects homeowners the most, are those overwintering pests who come inside buildings or structures to take advantage of the consistently warm temperatures and abundant food and water supplies.
Let’s take a look at how some of the most common pests overwinter, as well as some winter pest prevention tips.
Most species of cockroaches can’t survive temperatures below 15 degrees Fahrenheit. Because of this, many types of roaches including German cockroaches and American cockroaches, will make their way indoors to overwinter in your home. The good news is that lower temperatures also means lower activity and reproduction rates so even though they may be in your home, they aren’t reproducing nearly as much as they do in the spring and summer.
Some species of spiders become inactive at temperatures below 44 degrees Fahrenheit. Some (like the brown recluse) will overwinter inside buildings and shelters while others will go into a state of diapause. Spider activity will also decrease with colder temperatures because there is less prey available for them to hunt.
Many ants (like fire ants) will tunnel deep underground where the soil is warmer to survive the winter. Many ant colonies don’t survive until spring. Argentine ants will nest in pine trees over the winter to protect themselves. Most other ants will gorge themselves on food in the fall and seal themselves up inside their colonies, huddle together for warmth and go dormant until spring. Most ants will not overwinter inside your home unless they already have a colony established there.
Some species of adult female mosquitoes will overwinter in diapause. They will stop feeding and increase their fat reserves and then burrow themselves in storm drains, caves, or anywhere else they are protected from the elements until spring. Other female species can survive as larvae or eggs. Male mosquitoes don’t usually go into diapause and will die off with the colder temperatures.
Some tick species (American dog tick, lone star tick) are not active in the winter months. These ticks will decrease their activity levels, conserve water, and produce substances (like antifreeze) to help protect them from freezing and find a warm place to overwinter (burrowing underground or attaching themselves to a nice warm deer or dog). Other species (like the black legged tick) will stay active as long as temperatures are above freezing. All tick activity then increases in the spring in conjunction with an increase in the activity of their hosts.
Bees & Wasps
Lower temperatures lead to a decrease in sources of pollen for bees, decreasing their activity in the winter. Honeybees will return to their hives during the winter, forming a huddle around the queen and shivering and vibrating their wings for warmth. They will even rotate the bees on the outside of the huddle to the inside to make sure no one gets too cold. Bumblebees will produce several queens at the end of summer who will mate and then nest, usually in a hole in the ground. The rest of the bees in the colony die off. Carpenter bees will return to their hive and hibernate until spring with some of the older bees dying off toward the end of summer. Wasps usually die off in large numbers in the winter. In the fall, only mated females will find a safe place to overwinter while the rest of the colony dies off.
Regardless of what type of pest you are dealing with this winter, some simple steps can help you keep even the most troubling pests out of your home.
- Seal cracks and holes on the exterior of your home.
- Replace any loose mortar.
- Replace weatherstripping.
- Store firewood away from your home.
- Keep storage areas organized and store boxes off the floor.
- Check for leaky pipes and clogs.
- Keep gutters clear.
- Use door sweeps.
- Screen windows, doors, and chimneys.
- Keep attics, basements, and crawlspaces dry and ventilated.
If you have a pest that is taking over your home this winter, contact a professional pest control company for a free evaluation and customized treatment plan.