12 February 2010

Swamp Flat-tail Dragonfly - Austrothemis nigrecens

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Swamp Flat-tail Dragonfly - Austrothemis nigrecens

The Australian Faunal Directory states that dragonflies belong to the Suborder Epiproctophora, which has 6 Superfamilies, 18 Families, 73 Genera and 209 species within Australia. None of which include subspecies or damselfies, so plenty to keep an entomologist occupied. The Swamp Flat-tail Dragonfly Austrothemis nigrecens, is part of the Libellulidae family and the only species in the Austrothemis genus. It is distinguished from other genera by a small lump on the hind margin of the eye, which may be seen in some photographs (check the rear eye margin halfway down).

Austrothemis nigrecens is one of the most common Dragonflies in my district, being attracted to pools, deeper ephemeral swamps and small slow moving creeks. They are easy to identify by having distinctively flattened abdomens and males being orange/red, females a bright yellow, both with black markings, which as the photos show can vary slightly. They are around 4 cm (1.75”) in head/body length.

Austrothemis nigrecens is distributed widely in the Eastern States, but in WA is restricted to the SW corner where a permanent resident. Interestingly, with most dragonflies the males are more common, but locally the females of this species are considerably more numerous. Dragonflies with their large eyes have virtually 360 degree vision and with their powerful but agile flight, make them highly effective predators on flying insects, which are taken on the wing.