Friday, 15 March 2013

Week 14: Springtails (Collembola)


Springtails were the @SpeciesofUK from 3rd to 9th March 2013.

Springtails are tiny animals named for their ability to jump. They aren't actually a single species. They're a large grouping, 'Subclass,' of several thousand species, of which about 250 are found in the UK.

Springtails
[Source: Flickr Creative Commons © smccann]

Springtails are found all over the UK, most of the year round. They eat vegetation such as rotting leaves and bacteria, and so are often found in leaf litter and compost.[1]

What are springtails?

Springtails, Collembola, are a type of hexapod, meaning they have six legs on a thorax, just like insects. Springtails, however, aren’t insects. Insects have external mouthparts, whereas springtails don’t.[2]

Springtails are even more numerous than insects. A cubic metre of topsoil can contain 100,000 individuals. Mites are the only other group that bears comparison.[3]

Springtails are split into two sub-groupings: the linear springtails and the globular springtails.[4]

Linear Springtail
[Source: Flickr Creative Commons © Will_wildlife]

Globular Springtail
[Source: Flickr Creative Commons © Sandra-Photographie]

Being hexapods, springtails and insects are also part of the larger grouping of invertebrates called ‘arthropods,’ along with arachnids and crustaceans. Arthropods are easily the most successful animals on Earth, making up three-quarters of all known living and fossil organisms, over one million species in all.[5]

Springtails are the first arthropods that we have featured on @SpeciesofUK.

Another names for springtails is the “snow flea,” derived from some species’ habit of gathering en masse on the surface of snow.[6]

'Snow Fleas'
[Source: Flickr Creative Commons © mbalazs2]

Description

There are around 250 species of springtail in the UK. Most have an elongated body, six legs and two antennae.[7]

Springtail
[Source: Flickr Creative Commons © Jurgen Otto]

The springtail has two very remarkable adaptations – a springboard and a grooming device.

The springboard is a special forked tail called the furcula that the springtail keeps folded under its abdomen. It’s held in place with a latch, which when released lets the tail fall to the ground and propels the springtail into the air.[8]

The grooming device is a tube-like structure called the collophore, which many species use for grooming, stretching it right across their head and back. In fact, the Springtail’s scientific name Collembola is derived from Greek colle (glue) and embolon (piston), referring this tube which people used to think was used for sticking to surfaces.[9]

Underside of Springtail showing Furcula and Collophore
[Source: Flickr Creative Commons © cquintin]

Here is a fabulous David Attenborough video of springtails in full grooming and jumping action!


Springtail size can be 0.2mm up to 6mm, depending on the species. Some springtails can jump 6 inches into the air, many many times their own body length.[10]

Springtails are occasionally mistaken for fleas because they can occur in the home and they jump. But springtails have normal hind legs, whereas fleas have hind legs modified for jumping. Both springtails are fleas are wingless. But fleas lost their wing through evolution as a parastie, whereas springtails never evolved wings in the first place.[11]

Some species of springtail are blind. Others have eyes with up to eight lenses, held on its head capsule alongside two antenna.[12]

Springtail with Eye Lenses Structure clearly visible
[Source: Flickr Creative Commons © cquintin]

Reproduction and Growth

Springtail reproduction is simple. In most species, the male deposits a packet of sperm in a droplet on a leaf. The female wanders over and places her sexual opening over it.[13]

Springtail Breeding
[Source: Flickr Creative Commons © imarsman]

In some species, the male entices his mate to pick up his sperm packet by dancing and head-butting her. Here is a wonderful video of this absolutely extraordinary behaviour:


Breeding can occur virtually all year round depending on the species. It takes a few weeks to develop from egg to adult.[14]

Springtails have “ametabolous” development, meaning they look the same when they are young as when they are adult, just smaller.[15]

Springtails moult. After about five moults they are sexually mature, but they continue to moult throughout their lifespan.[16]

Springtail with Moults
[Source: Flickr Creative Commons © cquintin]

Predator and Prey

Springtail mouth parts are mostly retracted into the head. Some have mandibles while others are fluid feeders, having stylet-like mouthparts.[17] They feed on algae and decomposing vegetable matter, bacteria and fungi.[18]

Springtail on Fungus
[Source: Flickr Creative Commons © colinbrown]

Some springtails are carnivores and prey on tiny worms, other species of springtails and their eggs.

Unfortunately for them, being so common, springtails are also a favoured prey for a range of other species: spiders and beetles especially.[19]

Jumping Spider ready to Pounce on a Springtail
[Source: Flickr Creative Commons © Thomas Shahan]

Springtails and People


Springtails are harmless. But in large numbers they can be a bit of a nuisance for gardeners, in greenhouses or seedbeds.[20]

In 1996, fire fighters in Austria were called out to clean up a chemical spill on a road to discover that the patch was in fact several million springtails.[21]

Springtails Gathering in Large Numbers
[Source: Flickr Creative Commons © desultrix]

Strange but True…

Some springtails can actually emit light, a process called bioluminescence, though no one seems to be sure why this happens.[22]



1 comment:

  1. Fantastic information. The photo's are excellent. Looking at making a terrarium and discovered that these lovely little creatures are beneficial. Thank you. I'm off hunting!

    ReplyDelete