By Jennifer Devine. Featured photo from Pixabay.
Snow fleas (Hypogastrura nivicola) are tiny arthropods. According to Britannica, 84% of all known Earth species are arthropods, which have exoskeletons. This phylum includes insects, mites, centipedes, millipedes, spiders, and crustaceans such as lobsters and crabs. Snow fleas are related more closely to lobsters and crabs than any insect, even though the fleas have six legs.
I didn’t notice them until a few years ago, when I saw puddles with what looked like dirt floating on their surfaces. Then I realized that dirt specks on the snow were popping like corn kernels. My first thought was to lock up the dog because there was a flea infestation outside. Were other people experiencing this? Was it just a phenomenon that occurs every so often, like locusts?
Digging in, I discovered there was no problem. Thousands of little hexapods inhabiting a cubic meter can cause concern when you first sight them, but they aren’t what we think of as fleas. They will not bite, are not parasitic, and do not live on your fur baby. In fact, they are extremely beneficial to our ecosystem. Now I use them as my sign that spring is near.
A flea by any other name.
Our snow fleas are blue-black and about 1/16 inch long compared to the larger 1/8-inch size of a normal biting flea and a 1/4-inch sand flea. Snow fleas have a tail-like appendage, called a furcula, that unfolds from their abdomen to help them spring a few inches at a time, hence, their nickname, “springtails.” Think of a mouse caught in a mouse trap. The trap springs into the air and flips around uncontrollably as the mouse tries to get away. In contrast, a regular flea jumps using its hind legs and has more control.
Springtails live year-round and have few predators in winter. In warmer months, they are food for ants, beetles, centipedes and fungi. Especially fungi with host plants. The plants attract the springtails, which feed on the fungi. In the process, the springtails are paralyzed and become the food ⸺ providing nitrogen to the host plant. Adults work their way to the surface on warmer, sunny winter days. Their dark bodies bounce around and contrast with the snow cover. Their diet consists of decaying organic matter, leaves, bacteria and fungi that cause disease to our flora. Page 198 of “The Great Lakes Entomologist”, Vol. 1, No. 6 [1967], Article 1 states: “….I have seen uncountable numbers feeding on maple sap in the spring.”
They play an important role in natural decomposition and make fertile soil by promoting nutrient recycling. Think earthworms. It’s worth noting here that earthworms are not native, but springtails are.
There is a symbiotic relationship between that springtime smell from a chemical called geosmin, made from the bacteria Streptomyces, and springtails. This was studied in both the U.K. and Sweden then published in the scientific journal “Nature Microbiology”. You can also read an article on popularmechanics.com further explaining this relationship and referencing that study.
Short lifecycle of an ancient arthropod.
Spring is when mating occurs, and the female lays her eggs in the warming soil. After about three weeks, nymphs appear. They grow throughout summer and molt several times. In fact, they are in the dirt in your hand while you’re gardening! There are groups of people in the vermiculture community continuously finding these guys in their wormy compost (vermicompost) bins. They’ve also been found taking up space under commercial mushroom farms, according to InsectIdentification.org. In the fall, the “snow lice” reach their final molt stage, becoming adults ready to work all winter. Their lifespan averages two years, but they’ve been around as a species for millions!
Bad fleas inside, good fleas outside.
That’s not to say they won’t infiltrate a damp home or basement and cause chaos, including feeding on anything that can decompose, including damp cardboard. Please do your due diligence with moisture issues; put down some diatomaceous earth inside your home for them to consume, or call a pest company if needed. For the most part, you never have to worry!
According to study published in “Biophysical Journal”, snow fleas are able to withstand bitter winter temperatures, thanks to a “glycine-rich antifreeze protein” which lowers their body temperature. The protein in the snow fleas binds to ice crystals as they start to form, preventing the crystals from growing larger. In fact, by isolating this protein, researchers from places like the University of Chicago have been able to study not only the medical potential of its structure but also the suggested possible applications of this protein in safely preserving organs for human transplantation. See: https://www.esa.org/esablog/2011/01/28/snow-fleas-helpful-winter-critters-2/
“Got bit” by a winter phantom?
Don’t blame the springtails! Many bugs that bite can still be found inside and outside during winter ⸺ bugs such as fleas, deer ticks (what??), mosquitoes, chiggers, bed bugs and spiders ⸺ though they are less active in low temperatures. Unless you’re in the process of decay, you are safe from springtails. So, go out and live like there’s one less biting critter to annoy you. Put your foot in a puddle.
Jennifer Devine has a passion for writing and plants. Living in cities and homesteading off grid has offered a myriad of experiences, memories and adventures with her family, as they utilize the natural resources Michigan has to offer within their crafts, cooking and all-around lives.
