I had two phone calls today that started My snow has fleas."
Excuse me?" I replied, assuming that Snow" was the name of their cat or dog.
However, in both cases the descriptions were the same. Millions of small insect-like critters - about the size of a
speck of dirt - covered en masse on top of the snow.
Upon closer inspection, these small creatures, known as snow fleas (a species of a larger group called springtails),are not even true insects. They are actually classified as Entognathous hexapods, which is a separate group from the
I know, useless information.
But the interesting thing is that springtails are minute arthropods that have a distinct means of locomotion: they hop,much like fleas.
These arthropods have a fork-like structure (called furcula) at the hind end that is hooked under their abdomen. When
they want to move, they release their spring-loaded furcula, launching themselves into the air. Because they really
can't control their direction, where they land is anybody's guess.
Why they come to the snow's surface is also up to interpretation. No one really knows why they seem to magically
appear" on top of the snow. There are those who believe that they are attracted to algae growing on the snow's surface
(note to self: don't eat any snow, much less the yellow stuff); others think that this migration to the surface is a
reaction to overcrowding and a lack of food.
Perhaps they are like the rest of us this winter, and are sick and tired of continually being buried by the snow and
may be making a break to somewhere warm. Unfortunately for them, the channels and tunnels they carved to get to the
surface are not there when the sun goes down and the temperature drops. This creates a challenge for anything that is 1
to 2 mm long, and many of them are trapped and ultimately die.
Typically, we see them more often toward the end of winter as temperatures rise, so the fact I have had the multiple
inquiries into my office this week is somewhat uncommon.
So this got me thinking. Punxsutawney has its groundhog. Alaska has its marmots. Maybe we should have our snow fleas.
When they come out on those rare occasions in early February maybe it means spring will arrive early.
Not unlike many terrestrial bugs," springtails are present throughout our uppermost soil layers. They are decomposers
and in moist conditions with high amounts of organic matter, ridiculously high numbers may exist - upwards of thousands
per square foot. But the good thing is that, unlike the fleas that are external parasites and feed off the mammalian
blood, these snow fleas do not bite and are not dangerous to humans and other large animals.
If insects (or insect look-alikes) intrigue you, check out any book by Dr. Whitney Cranshaw, an entomologist with
Colorado State University. This guy knows more about arthropods (including snow fleas) in the Rocky Mountain region
than anyone I have ever met.
co.us or 382-6464.
Darrin Parmenter is director and horticulture agent of the La Plata County Extension Office.