Key to Australian Freshwater and Terrestrial Invertebrates

Phylum Arthropoda
Subphylum Hexapoda
Class and Order Collembola

Common names: collembolans, springtails

Overview

Collembola, or springtails, are small (>10 mm in length), wingless, soft-bodied hexapods. They can be either elongate and cylindrical or more compact and spherical in body shape. Springtails have small, simple eyes and their mouthparts are internal, hidden by oral folds or cheeks. Unique to the group is a forked, tail-like organ (furca) on the underside of the abdomen found in most springtails. By flexing the furca forward under the body and holding it under tension, they can leap considerable distances in the air when it is rapidly released, hence their common name. They are typically dull in colour, sometimes with mottled patterns, although many species are more brightly coloured with hairs or spines (tubercles) over their body.

Distribution and diversity

Springtails have a global distribution, including parts of Antarctica. They are widespread throughout Australia with the highest numbers found in organic rich, humid environments, such as soil and leaf litter of forests, and the lowest densities in arid regions. There are about 7,000 described species; however estimates are given of as many as 100,000 species worldwide. Twenty families, 130 genera and 353 species (78 introduced) are recorded for Australia, with the total number of species estimated at around 2,000.

Life cycle

Sperm transfer is indirect: the male deposits on the substrate a round, stalked spermatophore (sperm packet), that is picked up by a female. In most species, mating occurs during synchronised aggregation at the time of moulting. In other species, an elaborate courtship dance, instigated by the male, stimulates receptivity of the female. Males may also be highly sexually dimorphic, possessing structures that enable them to hold the female, often by entwining of the antennae. Some species are parthenogenetic. Eggs are laid either singly or in clusters, in or on the soil or leaf litter. Juvenile springtails resemble small adults and develop through several instars before reaching maturity. Adults continue to moult, up to 50 times throughout their lives. A single life cycle may take just 3�5 weeks from hatching to maturity; however in colder climates, such as polar regions and at high altitude, it can take much longer.

Feeding

Springtails typically have chewing (mandibulate) mouthparts and feed on a wide range of plant material as well as fungi, bacteria, algae and yeasts. Some species feed on decaying organic matter, while others are predatory on micro-organisms such as protozoa, rotifers and nematodes.

Ecology

Springtails are often considered to be the most abundant hexapods on Earth, with figures as high as 200,000 individuals per square metre recorded. They occur in the greatest numbers in soil and leaf litter, but also occur in logs, dung, ant and termite nests, the marine littoral zone, on the surface of still, freshwater, on or under snow in montane and polar environments, and in deserts and caves. A few species that feed on live plants, such as the clover springtail or lucerne flea (Sminthurus viridis), are pests of pasture plants and leguminous crops, especially lucerne. However, because of their abundance and ubiquity, springtails are a vital part of the detritus food web, facilitating breakdown of plant-material, nutrient cycling and enhancing of soil fertility and structure. Also because of their ubiquity, short life cycles, abundance and close association to the soil, springtails have also been used for environmental assessment and monitoring of habitat change.

Species of Collembola from Snug, Tasmania
Image credit: Tony Daley
used under a Creative Commons Attribution-NonCommercial-ShareAlike license

Katianna sp. from Hobart
Image credit: Tony Daley
used under a Creative Commons Attribution-NonCommercial-ShareAlike license

Entomobryidae species from Snug, Tasmania
Image credit: Tony Daley
used under a Creative Commons Attribution-NonCommercial-ShareAlike license

Species of Collembola from Perth
Image credit: Jean and Fred Hort
used under a Creative Commons Attribution-NonCommercial license

Collembola species from Tasmania
Image credit: Tony Daley
used under a Creative Commons Attribution-NonCommercial-ShareAlike license

Species of Collembola found in Tasmania
Image credit: Tony Daley
used under a Creative Commons Attribution-NonCommercial-ShareAlike license

Species of Collembola
Image credit: Photographer: Erich S. Volschenk
� Western Australian Museum

References and further information

ABRS Australian Faunal Directory: Collembola
Atlas of Living Australia: Collembola
Encyclopedia of Life: Collembola
Tree of Life: Collembola
CSIRO Entomology � Collembola
Checklist of the Collembola of the World

This work is licensed under a Creative Commons Attribution-NonCommercial 3.0 Australia License.