What’s up with the bugs?

How insects survive the winter

As fall moves to winter, there are no more pesky fruit flies in the kitchen or ants at the picnic. But, there are also no more butterflies, bees, and other more fun insects. Where do some of our favorite bugs go during the colder months? Some migrate, some hibernate (in a sense), and some leave their eggs to overwinter in a safe place to support next year’s generation. Let’s take a look at what some of the Chesapeake’s more iconic insects do during the winter months.

Butterflies

A monarch butterfly visits butterfly milkweed (Asclepias tuberosa) blooming at the headquarters of the Alliance for the Chesapeake Bay in Annapolis, Md., on June 6, 2019. (Photo by Will Parson/Chesapeake Bay Program)

Some butterflies, like the beloved monarch, migrate all the way down to Mexico during the winter. Others spend the cold months in a dormant state similar to hibernation, and/or endure the cold as caterpillars, a chrysalis (similar to a cocoon), or an egg. The time they are in this dormant period depends on the species.

Those that survive as adult butterflies could even hunker down in your own house. They might get lucky and find a spot in your cellar, closet, attic, etc. If you find a butterfly in the winter, lend them a hand. Try to get the butterfly into a simple enclosure like a cardboard box somewhere safe, and include a way for it to exit for when the weather becomes more advantageous.

Like many other insects, butterflies face threats year round. Habitat loss, including invasive plants overtaking their favorite natives, are a main threat. Consider researching your favorite butterfly species and planting some butterfly-friendly habitat for them to enjoy in the coming years.

Bees

One of our many buzzing friends on a purple coneflower

Some bees are social, and some are solitary. One of the most famously social bee species is the honeybee. I remember going to the science museum and feeling the honeybee exhibit for the heat they create around the queen. This is how honeybees spend the winter! Referred to as thermoregulation, they like to huddle around the queen to keep her warm in their hives.

During the colder months, they survive off honey reserves, and can generate enough heat to be 20 degrees higher than frigid outside temperatures. During the winter, honey bees can live in colonies as large as 50,000. To keep the heat in, some bees repair cracks in the hive or nest, similar to how we fix up a drafty wall in a wood cabin. Worker bees are certainly always at work.

To complicate things further, there are also semi-social bees. They don’t adhere to either bee lifestyle, but like to alternate, like an introverted extrovert. Bumble bee queens, especially new ones, hibernate in the soil as opposed to a hive. They like to dig little nests to wait out the cold, ready to reemerge and socialize in colonies of up to 200 when the weather warms. Some bumble bees require areas of undisturbed vegetation as well. These areas are best for bees when free of pesticides or other chemicals, of course.

Other solitary bee species also hibernate without a colony. Solitary species like carpenter bees like to find a nice place to hunker down like dry leaves, old logs, or old nests. Once they find their perfect spots, they reduce their metabolisms and use their fat stores from gathered nectar until it’s time to reemerge.

Whether a bee is on their own or surrounded by others, all bees face threats when they come out to greet the spring. To help our buzzing friends, reduce or eliminate your own pesticide use when plants start budding. If you must use pesticides, check labels to ensure it’s not harmful to helpful pollinators like bees. In the midst of habitat loss and climate change, planting some more habitat for the bees doesn’t hurt either!

Macroinvertebrates

An adult mayfly out and about after the cold months end

Benthic (aquatic) macroinvertebrates, or macros, have a pretty special life cycle. They generally survive the winter as larvae, gathering nutrients and preparing for the warmer months. Some spend all their time in the water, while others only live in the water when they’re young. Once mature, macroinvertebrates leave the water to pursue a life on land. A species like mayflies can take years to mature in the water, but survive as adults on land for only a few days to mate and lay their eggs for the next generation.

But, during the winter, macroinvertebrates shelter in the chilly water. Water is a surprisingly good insulator and keeps temperatures relatively consistent, especially if there’s an additional insulation layer of ice. Some macros will also find heat from the ground temperature, nuzzling under stream rocks or within sediments in a creek bed.

Macros are a great organism to sample during winter as well. If there’s an abundance of macros in a winter stream, that’s a good sign the water is clean and healthy. They’re a key indicator in how well a stream is doing, so don’t ignore them. Like the other insects discussed, pesticides, chemicals, etc. can all threaten macros during this time. Clearly, clean water is the most important thing when it comes to aquatic macroinvertebrates.

Beyond the bugs, don’t forget about the other critters sensitive to climate change, water quality, or habitat loss. Reptiles and amphibians also need safe places to stay during the chilly Chesapeake months. Habitat can also include simply not raking your leaves. Either way, remember to plant some things pollinators will enjoy, reduce your pesticide use, and do everything you can to ensure clean water for the critters.

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