Nothing is just a hop, skip or a jump away if you are a springtail.

Nor are those motions very simple either. Springtails are tiny creatures (1/16th to 1/8th inch) that look like insects and seem in all other respects to be insects, but aren’t. According to the classification gurus, they are not true insects. Unlike insects, they do not go through a major metamorphosis, having no larval or pupalstage. Also, unlike most insects that molt only until they reach adulthood, springtails continue to molt even after they have become adults.

Springtails were recently scientifically reassigned, and are known (in entomological circles) as hexapods (Greek for “six legs”). 

They do not use these six legs, however, for hopping, skipping, jumping or any other vertical movement, though they can engage them to crawl. Instead, springtails have developed a highly specialized appendage to catapult themselves skyward whennecessary. A fork-shaped organ, called a furca, folds under their stomach and is held in tension by a catch, called aretinaculum. When released, the furca propels springtails upward and forwar d, allowing these tiny beasts to reach a height of four inches. Thus, their name makes sense, because to an observer the furca may indeed appear like a spring-loaded tail.

It seems a complex adaptation for getting onward and upward. They must have evolved this springing system to make up for a lack of linear locomotion. Springtails are wingless wonders, incapable of flight. Unlike many of their insect relations, they do not possess wings, and neverdid. They are considered “primitively wingless” because they have never had wings, unlike other species that lost their wings as an adaptation to lifestyle (called secondarily wingless).

Springtails are old souls. They have been around for quite a long time. The oldest springtail fossil found was estimated to be 400 million years old! And these super-springers’ species are numerous. There are more than 6,000 known varieties, and scientists believe that these are not all that exist: the optimistic among them believe that this figure represents only 10 per cent of the number of the springtail species yet to befound. 

These springing sprockets make their mark in numbers of individuals too. In my yard recently, there has been a blitz of thesebugs. When seen, they generally appear in largenumbers. And I mean large. Springtails challenge other insects to beat their numbers since they can be found under the ground in densities of up to 250 million hexapods peracre. Their outbreaks aboveground are in response to less than optimal soil conditions. 

Moist, but not saturated, is perfect for springtails. They can live in a variety of habitats, but all must bedamp.  In addition to underground, springtails can thrive in a moist planter, on puddles, ponds or along seashores, atop snow (this type is called a snow flea), or on other wetsurfaces. Most common mass emergences are triggered by an overa bundance ofwater. After a prolonged rain, springtails must emerge from the ground or other super saturated locations in order tobreathe. Inundated soils hold less oxygen and force the springtails to the surface, which would explain their recent presence after days ofrain. 

The springtails seemed to have quickly disappeared, back to the damp dungeons of soil below. They will return someday, locked and loaded, ready to leap into our lives again, but only when their spring has sprung.


Suzan Bellincampi is director of the Felix Neck Wildlife Sanctuary in Edgartown.