Six legs and not an insect in sight

During winter we place buckets around our backyard to collect the rain. The water collected is used to top up the bird bath and fill the ‘bushfire-ready’ wheelie bins around the house in preparation for the next fire season. If the buckets are left for a few days the water surface becomes populated with a writhing mass of grey bugs (see picture left). In close up (pictured below) these creatures have six legs. For the last three weeks I have been poring over my insect books trying to identify them, to no avail.

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Springtails and their mitey friend

But on Friday night at the Focus on Fauna talk entitled Leaf Litter Invertebrates a photo of the very same animal was shown. And they are not insects at all (despite the six legs). They are commonly known as Springtails, one of the most abundant animals on the planet. From a classification perspective they have been moved from Class Insecta to Class Entognatha because, unlike insects, they have internal mouth-parts.

Springtails are so called because they have an appendage under the body that they can use to fling themselves through the air if threatened. Most springtails are terrestrial, living their lives in the leaf litter and soil. Some spend their lives on the surface of water. The eggs when laid sink to the bottom and when the instars (larvae) hatch, they float to the surface. Sometimes I have seen Springtails hanging out on the water surface with a number of mates including Red Mites. It’s safer to go swimming with friends.