27 April 2010

Western Ringtail Damselfly - Austrolestes aleison

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Western Ringtail Damselfly - Austrolestes aleison

Austrolestes aleison is part of the Lestidae family along with a couple of other genera, although only Austrolestes is known to occur in Western Australia and these are commonly known as Ringtails. There are five Ringtail species listed for the SW of WA, although I have only seen three locally. The Western Ringtail is quite distinctive and unlikely to be confused with the other WA species, the male having narrow blue rings along its abdomen against a dark background, whilst the female has pale blue rings and none at the tail end. Also the dorsel colour of the female is a bronze brown and the male much darker, but these can vary to the eye, depending on the angle of sunlight.

The thorax marking in profile is a distinguishing feature of Austrolestes aleison, as is a dorsel wineglass marking on the male just behind the thorax. This species is one of the few damselflies restricted to the southwest of Western Australia, although a similar looking species the Cup Ringtail A. psyche has an Eastern States distribution.

Locally, most of the Damselflies disappear by the end of March when there is a big influx of Dragonflies anxious to complete their egg laying before the weather gets too cold. So although these Western Ringtails can normally be seen daily during the warmer part of the year, they no longer can be found, but no doubt will turn up again next spring/summer.