While you were watching Lars Bystoel of Norway fly more than 240 meters from a ski jump near Turin, Italy, nearby in a snow pile an equally remarkable display of athleticism was taking place on a somewhat smaller scale. Snow fleas, also known as springtails, are performing Olympian deeds in your backyard. Today I watched a rather robust snow flea named Arnold execute a standing broad jump of prodigious proportions. Arnold stands about 1.5 mm tall. After a few preliminary leaps, Arnold set a record by jumping 82 mm on his third and final attempt. This leap is roughly equivalent to Michael Jordan standing on the goal line of a football field and leaping to the opposite 20 yard line 80 yards away. Surely, this leap was worthy of a gold medal by anyone’s standard. Snow fleas are tiny, six-legged relatives of true insects. They belong to a part of the arthropod clan called Collembola and are among the most ancient of six-legged creatures. Collembola have been on the planet for 380 million years, roughly 30 million years before the first animals with backbones wriggled from the primordial sea to the land.
The springtails featured in this bug of the week belong to the family Sminthuridae. Cat fleas, dog fleas, even bird fleas, conjure images of small, black, jumping, biting insects. Snow fleas are quite different. Instead of living as external parasites of other animals, snow fleas and other springtails eat tiny plants, decaying vegetation, bacteria, and fungi. On one occasion I found a large colony of Collembola happily living inside the water tank of someone’s commode. At certain times of the year they become very abundant on the ground or near water. Collembola multiply on the forest floor and move about despite the chilly temperatures. They can reach amazing densities and their dark coloration makes them quite apparent on white objects such as patches of snow.
The propulsion system used by snow fleas differs from that of their insect relatives. True fleas such as cat and dog fleas have a flexible protein called resilin in their legs. Resilin is compressed and stores energy that is released in a split - second burst to power the jump. Snow fleas and many other Collembola have an odd forked shaped appendage called a furca. The furca is tucked beneath the body most of the time and held in place by a clasp called the retinaculum. When the snow flea wants to leap, the clasp releases the furca just like a catapult and the springtail is propelled through the air. No need to feel blue with the Olympics winding down. Simply go outside the next time it snows and watch some springtail events.