Cold-weather insects: these winter pollinators are super cool(ed)

Humans have evolved several traits that make us special—big brains and complex cognitive abilities being our top brag. However, there are other characteristics that we aren't nearly as boastful about but perhaps should be. Paramount among those is a skill called endothermism! That is, our bodies' ability to maintain warmth without relying on the sun or other external sources of heat. In fact, humans, along with other fellow mammals and birds, are among only 1% of all species that can perform this neat little trick.

The adaptations of cold-weather insects and invertebrates

The chink in our thermostatic armor is that, unlike mammals like bears, we can't drop into a hibernation state when things get too frosty. This is where the advantage really shifts to the insects and other species that have adapted to survive during periods of extreme cold. In a previous story, I wrote about how bumble bees survive winter during a period of diapause. However, there are some insects that not only can survive freezing temps for months at a time but are able to move about in the snow due to their ability to "supercool" their bodies below the freezing temperature of water. They do this while maintaining the fluidity of their internal liquids thanks to specialized chemicals called "cryoprotectants," which act like antifreeze. Snow fleas (a type of springtail, an insect-like creature) are the winter invertebrates most commonly encountered outdoors, but there are also winter moths, specially adapted snow flies, and even spiders that can survive in freezing conditions. Adding to this list are pollinators that have adapted to visiting winter-blooming flowers.

What does winter pollination look like?

While it is uncommon for North American flowers to bloom during the winter months, several plants do, including witch hazels and snowdrops, which are both pollinated primarily by flies. Many species of fly overwinter as adults (as opposed to most bees, which do so as pupating larvae). On sunny, winter days, flies can quickly warm up enough to begin visiting these frigid flowers. As a result, some winter-blooming plants like skunk cabbage release fetid odors that attract flies who dine on rotting meat. It's worth pointing out that while flies can be very effective pollinators, many are "accidental" pollinators. This means that they are visiting blooms because they have been duped by a plant's smell, or are there to feed on nectar, inadvertently spreading pollen from bloom to bloom in the process.

When we consider ways to protect pollinators from pesticides, the information that is often shared focuses on a very limited number of species—often only one, the European honey bee. Honey bees are only active during the day, returning to the safety of a hive at night. However, many pollinator species, from bees to beetles to flies and more, are active day and night, across all seasons. Despite what the label may say, there really isn't a safe time to spread pesticides in your garden or crop. Each application will impact some creature that we may not have considered, so before applying a pesticide it's worth asking whether it is really needed. WWF supports a thoughtful approach to pest management, only using pesticides when they are agronomically justified. Currently, this isn't standard practice for leading crops like corn and soy. Nearly 100% of the seeds of non-organic corn and approximately 70% of soy are pre-treated with pesticides that harm pollinators, birds, deer, and other large wildlife, soil organisms, aquatic systems, and even humans.

Learn more about WWF's work to protect pollinators from unhelpful pesticides.