Springtail populations are often very, very large, but these tiny (3-6 mm) arthropods are not usually noticed. The common name, "springtail", is quite appropriate. When the springtail is at rest, a forked structure, called a furcula, arising on the underside of its body near the tip of its abdomen, is folded forward and held in place with a latch-like structure, called a retinaculum. When the latch is released, the furcula is slapped down against the supporting surface pitching the springtail up into the air. This mechanism is atrophied or reduced in a number of species. Springtails do not develop wings, and continue to molt after they reach maturity, although they don't get any bigger. Adults use the periods between molts alternately for feeding and reproduction.

While springtails are usually discussed in entomology books, some authors now relegate the insects to a subclass of the Class Hexapoda (arthropods with 6 legs) rather than placing them in their own class. Springtails, early offshoots in the hexapod line, are placed in a different subclass and, hence, are not really insects. Fossils of springtails from the Devonian period found in Scotland are the oldest known hexapod remains. Today we recognize about 6000 species world-wide with close to 700 species in North America.

Springtails occur in damp areas and are important recyclers, most species feeding on decaying vegetable matter, fungi and bacteria. One reference said that they are among the few organisms known to break down DDT in the soil. Some species do create problems in gardens, greenhouses and mushroom cellars. During the winter, one species, the snow flea, eats algae and fungal spores found on the snow. People collecting buckets of maple sap may find it a pest. One species reportedly causes human dermatitis.

In 1982, the Falkland Islands honored one soil dwelling springtail on a postage stamp. Images of a number of color paintings produced by artist A.T. Hollick over 100 years ago can be found at Gordon Ramel's entomological World Wide Web site.

While there are probably lots of springtails around the Nature Center, they have only been noticed in the springtime. (I saw them in mid January.) Look for purplish-colored patches floating on the surface of freshwater puddles, such as those on the dirt road beside the railway tracks. Each patch contains a number of tiny springtails, ranging in color from whitish to icy blue to blue and pink to purple. (I don't know if all of these are the same species - some may be juveniles, others may have molted recently.) Wandering among the springtails I found were some brown, oval mites (predators?). Remember, these arthropods are small - a magnifier of some type will help (you've got time to go and get one).

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Ron Lyons (volunteer 1990-1999)
Chula Vista Nature Center, 1000 Gunpowder Point Drive, Chula Vista, CA 91910-1201