Let’s begin at square one with this. “Overwintering” merely means how insects survive during the coldest season. There are several ways they are able to live through temperatures nobody thinks they should be able to survive. They are able to overwinter as eggs, pupae, or as adults, but more often than not, they prefer going indoors, burrowing under fallen leaves, or behind tree bark.
Mosquitoes, ladybugs, caterpillars, boxelder bugs, butterflies, crickets, stink bugs, flies, spiders, and moths are just some of the pests that can overwinter. Wondering how pests survive the winter? Here are just a few of the ways they have been able to stay alive during a New England winter.
Migrate: Not everyone stays put when the temperatures drop. It’s not just humans that will move away during the colder months. Many pests will migrate to warmer weathers to escape extreme cold. The most common example is the monarch butterfly, but there are even some insects that will migrate north in the spring. The most common pests that will use migration during winter months are crop pests like beetles, moths, and dragonflies.
Swaddle: It usually works with an infant, right? Swaddle them up in a blanket and they will rest happily for a while. The same idea will help protect the immature larvae from the cold. A woolly bear caterpillar, for example, will burrow under heavy leaf piles for protection while a spider can actually produce a compound called glycerol that works very much like antifreeze does in your engine. Grubs simply dig down as deeply as they can until the soil is warm again.
Egg: Not many pests actually lay eggs at this point in the year. But the most common Midwest pest, corn rootworms, do. Also the praying mantis – and all praying mantids – and the dreaded spotted lanternfly can!
Pupa: This is one of the stages that all insects who complete a full metamorphosis (for example, butterflies) go through. The pupae are actually kind of swaddled, too, so you can find them attached to plants waiting out the cold.
Genetics: There are some insects that, in their nymph stage, can handle temperatures as low as 23ºF (-5ºC). They have freeze tolerance mechanisms that actually keep their tissue from freezing solid. The nymph stage is kind of like the teenager of the insect world. Not quite mature enough to be an insect, but more so than at the pupal stage. The nymphs of flies like the mayfly, the dragonfly, and the stonefly can actually live in bodies of waters like streams or ponds, even beneath the ice. These nymphs grow the whole winter because they feed the whole time. This helps them come out from their hiding place in the spring as fully grown adults.
Hibernate: Some pests will hibernate in their natural habitat like the honeybee. They form large groups called clusters to create warmth for all. They are even able to bring up the temperature of their bodies by vibrating the muscles in their wings. Many other pests like spiders will be looking for a nice warm home to escape the cold, and your home or business is probably looking pretty good to them. Wasps will be searching out eaves or attics to live out the winter in.
It sounds like insects have a lot of choices when it comes to living through the winter months. It’s even easier for them if the temperatures stay pretty constant and the winter is a milder one than normal. A heavy snow can provide the insects below the soil even more shelter from the cold air, so they seem to be able to survive no matter what.
It also helps that they stay very inactive, going into a suspended state. During that time, development and growth, in addition to activity, are literally suspended. Their metabolic rate only goes high enough to stay alive. With all of these techniques and strategies, if you were wondering where do pests go in the winter, they are all around us.