David Element's Wildlife Web Page Dragonflies and Damselflies 18

David Element

Wildlife Photography

and Digital Video Images

____________ Dragonflies and Damselflies 18

HIGHLAND DARTER Sympetrum nigrescens

COMMON DARTER Sympetrum striolatum (m)

SOUTHERN DARTER Sympetrum meridionale

SOUTHERN SKIMMER DRAGONFLY Orthetrum brunneum (m)

GREEN-EYED HOOKTAIL DRAGONFLY Onychogomphus forcipatus (m)

The first picture illustrates a Highland Darter Dragonfly. This insect was photographed in the Ardnamurchan Peninsula of north west Scotland and it shows the characteristically darker markings of this dragonfly when compared with those of the very closely related Common Darter Sympetrum striolatum which is illustrated in the second photograph and also elsewhere on this website - see Dragonflies and Damselflies 9. See also illustrations of the Black Darter Sympetrum danae on Dragonflies and Damselflies 1, 10 and 28. After many years of debate the classification of the Highland Darter remains unclear. There are two schools of thought. The first of these presents the view that S. nigrescens is simply a melanic form or sub-species of S. striolatum and the second that it is a full-blown species in its own right. There does not seem to be any documentation settling this argument on the internet at the time of writing and the author would be grateful for any feedback from experts working with these insects, particularly if conclusive DNA analysis has now been performed. Observation of the extent of the black facial markings of darters is an important aspect of definitive identification of several very similar species. Most of these photographs have been taken from the wrong angle or from too far away to enable these differences to be seen clearly – indeed it may be necessary to obtain very close-up portraits or to examine the insect under a magnifying lens to be certain of the identity.

The remaining three illustrations are of European species, all of which are absent from the UK. These dragonflies were photographed at different locations in France. The Southern Darter is a migratory species of a rather lighter build than the other red/brown darters. The mature male Southern Skimmer may be readily distinguished from other northern European skimmer dragonflies by the blue pruinescence which extends from the front of the thorax to the very end of the abdomen. See Dragonflies and Damselflies 10 for comparative views of the Keeled Skimmer and the Black-tailed Skimmer (the very similar Orthetrum albistylum has not been included on these pages yet). The male Green-eyed Hooktail is shown in a typical riverside pose atop a well-rounded stone. Further illustrations of this species and its close relatives may be seen on Dragonflies and Damselflies 11.