Snow Fleas Are Peppering The Snow
Duringwarming temperatures at this time of year the snow can be covered with tiny black specks (1 – 2 mm long), resembling pepper sprinkled on the snow. If you watch them for a period of time, you’ll see that these specks move — leap, in fact — a distance often several times their body length. These moving specks are called snow fleas, a species of springtail, not a type of flea. For that matter, they are not insects, but close relatives to arthropods, specifically crustaceans. During most of the year snow fleas live in the soil and leaf litter, consuming fungi, algae and decaying organic matter. On warm winter days they appear on the surface of the snow, often at the base of trees or in track indentations.
Their acrobatic prowess is achieved not with wings, which they lack, but with two tail-like spring projections, or furcula, which are held like a spring against the bottom of their abdomen by a kind of latch. When the snow flea wants to move, the latch is released and the furcula springs downward, catapulting the snowflea as far as 100 times its body length.
Snowfleas in the genus Hypogastrura possess three pinkish anal sacs which are usually located inside the snowflea, hidden from view. Just before jumping the snowflea everts these sacs from its anus. Their function has not been confirmed, but many biologists believe they serve as a sticky safety bag which prevents the snowflea from bouncing around when it lands.
The anti-freeze protein that allows snow fleas to be active at colder temperatures than insects is being studied in the hopes that they can be used to better store transplant organs.
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Snow Fleas Emerging
Yesterday was the kind of day when you could not take a step without knowing you were crushing hundreds of Snow Fleas, or Collembola, those tiny black specks on the snow. Their presence is a hopeful sign in northern New England, as it often signals the coming of spring, which we are more than ready for.
This non-insect arthropod is a type of springtail (not a flea). Springtails are no longer considered insects, but are classified as hexapods. These miniscule creatures sometimes come to the surface of the snow on warm winter days but are active year-round in leaf litter, feeding on algae, fungi and decaying organic matter.
Snow Fleas do not bite, nor do they sting. What they do do is catapult themselves impressive distances by means of an appendage on their underside called a furcula which snaps and propels them through the air. They have a soft landing due to three anal sacs that they evert from their anus just before launching themselves. (To see a photograph of these sacs go to a 2012 NC post on Snow Fleas: https://naturallycuriouswithmaryholland.wordpress.com/2012/03/09/snow-flea-mystery-appendage/) (Photo: Snow Fleas clustered in the track of a Black Bear that recently emerged from hibernation)
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