Springtail Speculations

Prior to living in Illinois, my only relationship with the insects known as springtails was from their late winter/early spring appearance on top of snow, where for all the world it looked like someone had tripped while carrying a container of ground pepper, dumping its contents all over the white expanse.  Upon close observation, each little flake of pepper takes its turn popping up into the air, drawing the attention of even the most casual of observers.  These critters are affectionately known as snowfleas, even though they are not even remotely related to fleas.

 Snowfleas ( Hypogastrura nivicola ), image taken at a tracking workshop at Kawing Crow Awareness Center, Greenfield, NY - March 2, 2010

Snowfleas (Hypogastrura nivicola), image taken at a tracking workshop at Kawing Crow Awareness Center, Greenfield, NY - March 2, 2010

Last spring, while sharing the wonders of aquatic insects with many school children, we discovered that the surface of the pond here at Severson Dells was covered with springtails - thousands of them (sadly, I have no photos).  I was well and truly stunned - I had no idea they would live on water...literally.

This spring, we found them crawling up and down the trunks of trees.  

 Springtails on tree, Severson Dells Nature Center, Rockford, IL - March 30, 2018

Springtails on tree, Severson Dells Nature Center, Rockford, IL - March 30, 2018

Obviously there is more to springtails than I had originally thought.

Some "quick" research online turned up the usual set of brief verbatim snippets, but then I hit the motherload, a whole book (over 300 pages) about nothing but springtails:  Biology of Springtails by Stephen P. Hopkin.  As fascinating as these insects are, however, I wasn't about to read the whole thing (well, I couldn't, because a) the online review I found had more than half the book missing, b) I wasn't going to spend nearly $200 for an e-book, and c) I simply don't have time to read a scientific tome just to write a few paragraphs for a blog).  But I will share with you some of the highlights, because these really are pretty nifty creatures; then YOU can go buy the book and fill in the rest of the story.

So, Springtails -  subclass Collembola.  Springtails are fairly primitive insects, although there seems to be some debate as to whether or not they are truly insects.  Most enotomologists are happy keeping them in the phylum Arthropoda, so I shall as well.  These insects are tiny - most falling somewhere between 1/16 and 1/8 of an inch (don't let the photos above fool you).  When I said they look like little pepper flakes on the snow, that was no exaggeration.

The name springtail comes from the really nifty appendage they have underneath the abdomen.  This forked "thing," called a furca, is folded underneath the insect and held in place until the springtail needs a quick get-away, then *snap!* it is released (think mouse trap), propelling the insect upwards and away from the impending danger.  Some species can fling themselves many times their own body length in a mere fraction of a second.  On the other hand, those species that live deep in the soil and rarely, if ever, venture forth, may have greatly reduced or even non-existent furcas (furcae?).  Being able to fling themselves with the furca is the only way these insects will "fly" - they have no wings, and therefore are grounded.

Actually, as I continued reading about these insects, I discovered that they have been found way up in the air - caught on sticky traps or in nets pulled by airplanes!  It is believed that they make use of the wind to disperse, climbing way up into the tops of trees when conditions are just right, and hitching a ride, much as young spiders are known to do (only sans the spider silk parachutes).

Now, the scientific name, Collembola, is equally fascinating.  It is from the Greek, as so many scientific names are, and it breaks down as glue (colle) and piston (embolon).  This appellation was given to the critters because of a second interesting feature:  the ventral tube.  This tube is apparently important in the animal's fluid balance, but it is also sticky and can help them stay on slippery surfaces.  Additionally, it can help right the insect after it has flung itself away from danger.

Over 6500 species of springtails have been described to date.  Some live on the surface of the ground/trees (epedaphic), while others are active below (euedaphic).  They live in every environment - including Antarctica, on the surface of water, and even deserts (although they are much less common here).  They are very important in the decomposition process and in maintaining soil health.  They are mostly harmless to humans (don't sting, don't bite), although there are some species that feed directly on plants and can be problematic for agricultural interests.  Most, however, feed on fungal hyphae and/or plant detritis.  There are even a few that are carnivores, gnoshing on nematodes, rotifers and even other Collembola!

So, if you are out walking our trails this spring, and you stop to look at the trunk of a tree and see it alive with little pepper flakes crawling up and down, say hello to the springtails!  If you have a hand lens on you, take a look at some of them up close.  See if you can see the furca.  

The world is full of amazing things, most of which we never see.  Take a moment to look - enchantment is everywhere around us.