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A maturing male Epaulet Skimmer (blue pruinose slowly developing) showing the single white stripe on the side of the thorax.
English common name: Epaulet Skimmer (Burmeister, 1839)
Scientific name: Orthetrum chrysostigma
Family: Libellulidae
Total length: 39 to 46mm
Hind Wing length: 27 to 32mm
Flight period in Iberia: Late March to mid December
Habitat: Marshes, streams & pools in open terrain, plus man made water bodies.
The Epaulet Skimmer is one of a number of dragonfly species where the mature male is predominantly blue and the female is predominantly a tan/brown colour. However it is unique amongst the Skimmers occurring on the Iberian peninsula in having a single white stripe or “epaulet” outlined in black on each side of the thorax. These are clearly visible when the insect is viewed from the side, running from just above the middle leg to just below the base of the forewing and are present in both sexes regardless of their maturity (with the possible exception of really old males).
There is often a very small amber patch at the base of the hind wing which may serve to help separate it from the similar Southern Skimmer (Orthetrum brunneum) and the Yellow-veined Skimmer (Orthetrum nitidinerve).
The Keeled Skimmer (Orthetrum coerulescens) has pale stripes on the upper surface of the thorax, but when viewed from the side they appear to run along the top edge of the thorax - from the pronotum to the forewing.
A pair of copulating Epaulet Skimmers in the wheel position at a fountain, the waisted abdomen of the male is clearly visible.
Sometimes found around man made water bodies such as drainage channels & water tanks, the Epaulet Skimmer may utilize such sites as breeding habitats. In March 2008 a recently emerged (teneral) male, complete with the cast off larval skin (exuvia), was found clinging to one of the few stems of vegetation growing on the wall of a deep concrete water tank. The tank, which was adjacent to the main N340a near Nerja in Andalucia, measured approximately 1.5m x 1.5m and fed the leats radiating into the surrounding agricultural land. As water only appeared to flow out of the tank I can only assume that the larval stage was completed entirely within the confines of the tank. The presence of an exuvia is regarded as being conclusive proof of successful breeding at any locality.
Distribution: Southern Portugal & Spain, North Africa & the Near East. Not uncommon in southern Portugal and Spain, absent from the north of the Iberian peninsula but perhaps expanding its range in that direction.
The Epaulet Skimmer is widespread throughout the Sahara, its larvae able to survive in moist sand, suggesting that it is an insect very well adapted to surviving in an arid landscape.
Similar species: Superficially similar to the Keeled Skimmer (Orthetrum coerulescens), the Southern Skimmer (O.brunneum) and the Yellow-veined Skimmer (O.nitidinerve), however unlike those species the male Epaulet Skimmer has a noticeably waisted abdomen.
A male Epaulet Skimmer covered in debris recovering from having fallen into the water as it emerged from its larval stage in a concrete water tank.
CREDITS
Thanks to Steve Jones of Cornish Nature for the images and excellent, informative text in this article.
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