David Element's Wildlife Web Page Dragonflies and Damselflies 8

David Element

Wildlife Photography

and Digital Video Images

_____________ Dragonflies and Damselflies 8

LARGE RED DAMSELFLY Pyrrhosoma nymphula (m)

AZURE DAMSELFLY Coenagrion puella (m)

COMMON BLUE DAMSELFLY Enallagma cyathigerum (m)

COMMON BLUE DAMSELFLY Enallagma cyathigerum (f)

VARIABLE DAMSELFLY Coenagrion pulchellum (m)

WHITE-LEGGED DAMSELFLY Platycnemis pennipes TENERAL

RED-EYED DAMSELFLY Erythromma najas TENERAL (m)

SMALL RED-EYED DAMSELLY Erythromma viridulum

SCARCE BLUE-TAILED DAMSELFLY Ischnura pumilio (f)

BLUE-TAILED DAMSELFLY Ischnura elegans f. typica

BLUE-TAILED DAMSELFLY Ischnura elegans f. rufescens

BLUE-TAILED DAMSELFLY Ischnura elegans f. violacea

SMALL RED DAMSELFLY Ceriagrion tenellum (m)

The Large Red Damselfly is the first species on the wing, sometimes appearing as early as April if conditions are suitable. This distinctive insect is common and widespread throughout the British Isles and the only possible confusion species, the Small Red Damselfly, has much reduced antehumeral (thoracic) stripes, red legs and no black markings on the abdomen of the male. This latter insect also has a much more restricted distribution than the Large Red and a later flight period. Females of both species may be extensively marked with black and each has more than one colour form. It is often easiest to identify female damselflies by association with males of the same species and as a general rule colour is not always a dependable identification feature. Damselflies are zygopterous (i.e. all four wings are of a fairly similar shape) unlike those of the dragonflies (Anisoptera) in which there are two distinctly different pairs of wings and a much more robust body.

The Azure Damselfly is an extremely abundant insect which often overlaps in distribution and emergence period with other blue damselfly species, particularly the very similar and comparably numerous Common Blue Damselfly (which actually belongs to the separate Genus Enallagma). Most of the remaining predominantly blue damselflies have a much more limited distribution than these two species. The Azure Damselfly is absent from the northern half of Scotland. Although many damselflies are difficult to distinguish, there are characteristic markings on the pronotum and abdomen which allow the experienced observer to separate them to species in the field. The male Azure Damselfly has a 'U' - shaped black mark on the second abdominal segment (see also the Variable Damselfly) and narrower blue antehumeral stripe than those of the Common Blue Damselfly. These markings are evident in the photograph of the male shown above. There are also subtle differences in the pronotal shape which aid with the identification of the females of these and other species, but note that the extent of the black markings and even the ground colour of damselflies may not be consistent even within a species. There is insufficient space available here to fully illustrate all of the damselfly species or all of their forms and a good field guide is necessary for their study.

The male Common Blue Damselfly has broad blue antehumeral stripes, only one stripe on each side of the thorax and a characteristic club-shaped marking on the second abdominal segment. The upper surface of the eighth and ninth abdominal segments is entirely blue - all other blue damselflies apart from the Northern Damselfly (not illustrated) have some black on segment nine. The pair shown above are in the 'wheel' mating position.

The Variable Damselfly has a more slender body than either of the two commonest blue damselfly species and the blue antehumeral stripes of the male are usually divided by a small area of black, and therefore described as 'incomplete'. However, this damselfly has been accurately named and the markings may differ between individuals. Great care should be taken with the identification of females as other species are very similar, notably the blue form of the Azure Damselfly. The pronotal shape is particularly significant as an identification character. Photographing this insect is an energy-sapping exercise as males will fly for a short distance if disturbed, often moments before the would-be photographer presses the shutter release! Only those with strong knees should apply...

The White-legged Damselfly is a strikingly marked and robust insect which inhabits the well vegetated margins of slow flowing clean river systems in the south of England. It is often found in the company of such indicator species as the Scarce Chaser or the Club-tailed Dragonfly (both illustrated elsewhere). Immature males and females are very pale and the adults assume pale blue and pale green ground colours respectively as they mature. The white tibiae are distinctive, although these only become really obvious on close examination. The markings are finely defined and clean in appearance and dissimilar to those of any of the other blue damselfly species.

The Red-eyed Damselfly is another robust species with a stronger flight than many other damselflies. The fully adult male possesses characteristic deep red eyes and a bright blue pruinescent band at the tip of the abdomen. A pale green immature (teneral) male is shown above. The red eyes used to be a unique feature amongst British damselflies until the very recent arrival of the more lightweight Small Red-Eyed Damselfly Erythromma viridulum which has now become established as a breeding species in Essex and parts of the Lea (Lee) Valley. All dragonfly watchers would be well advised to scrutinise populations of Red-eyed Damselflies in case they spot this newcomer, which has only recently been included in any of the current field guides as a British species. Mature Red-eyed Damselflies are typically observed on floating vegetation some distance from the water's edge and they are therefore rather more challenging as photographic subjects than most other damselflies. Water lilies are a favourite perch and these are aggressively defended against would be intruders of the same and other damselfly species.

The Scarce Blue-tailed Damselfly is an uncommon insect in Britain with population concentrations in southern Wales, Anglesey, the south west and southern coastal counties of England. This species may also be found in scattered populations in parts of Ireland. Poorly vegetated shallow pools are used for breeding and these are often created by human activity. The photograph above shows a female which was photographed in northern Spain, many hundreds of miles from the distribution range shown on the map in R. R. Askew's authoritative 'The Dragonflies of Europe'. This almost certainly reflects the difficulties associated with obtaining authentic records from poorly recorded areas of Europe. This species is most likely to be confused with the Blue-tailed Damselfly (see below).

The Blue-tailed Damselfly is another very common species which is able to utilise almost any water-body with the exception of fast-flowing rivers. It is quite tolerant of pollution or increased salinity and is therefore able to exploit habitats which would be entirely unsuitable for some of the more fussy species. The eponymous 'blue tail' is actually abdominal segment nine which is entirely blue in most (but not all) examples of this species. The female progresses through different named colour forms as she matures, but even these are not consistent. Immature females have attractive pink (rufescens - see above) or violet (violecea) forms and each of these may then develop into less brightly coloured fully adult insects (some form violacea mature into a blue form typica resembling the male). Confused? Well fortunately this insect is easy to recognise, but once again the use of a well illustrated field guide is advised when researching the colour forms.

The Small Red Damselfly is an uncommon, predominantly wet heathland species with a southern and western distribution. It is weak flying and rather difficult to see as it often roosts on grasses and blows with the breeze. The male (shown) has red legs and an entirely red abdomen and these features should be compared with those of the Large Red Damselfly illustrated on this page and also on Dragonflies and Damselflies 1. There are several different colour forms of the female with varying amounts of black on the abdomen. In form erythrogastrum the black is entirely absent and these females closely resemble the male.