Coenagrion armatum
Coenagrion armatum (Charpentier, 1840)
Local names: Dark bluet, Norfolk damselfly, Hauben-Azurjungfer, Donkere waterjuffer, Agrion armé, Griptångflickslända
Species Information
Description
In general appearance it looks more like a stocky Ischnura than a Coenagrion.
Males are blue and black, with the dorsal part of the abdomen almost completely black except for the abdominal segments S1-S3, S8 and S9 that are light in colour with a characteristic pattern. Antehumeral stripes either absent or reduced to spots. Side of the thorax bluish-green. Lower appendages on the males are particularly long, often as long as the last abdominal segment, and dark in colour with whitish pruinosity. The appendages earned the species its name, armatum is latin for armed.
Females also dark with abdominal segments S1-S3 and S8 partly blue. Antehumeral stripes are present and complete omn females. The colour of the light portions of both sexes can vary from light blue to olive green. Immature females are pink-orange.
Size
Habitat
Coenagrion armatum is found at shallow unshaded parts of mesotrophic to weakly eutrophic pools, ponds and lakes. In Fennoscandia it is occasionally found in slow-flowing river sections. Here it occurs among large swathes of sedges, Water horsetail and low reed. The key factor determining habitat suitability is the vegetation which need to be a rather dense growth of helophytes in shallow water of generally up to half a meter deep. In order to provide both shelter and space to move, the vegetation should neither be too low nor too high during the flight period. Suitable conditions can be found in natural and semi-natural habitats such as reed beds and peat excavations in ferns and wet meadows. In the later types of habitats, the species is dependent on mowing and the cyclical creation of new peat excavations, as otherwise its preferred habitats disappear due to the natural regrowth of vegetation.
Distribution
This species is found throughout northern Europe but is at present rare to very rare in large areas. The species has probably always been scarce in Great Britain, the Netherlands and Germany. It is currently extinct in Great Britain and only known from a small number of relict populations in the Netherlands, Germany and Denmark. It has a more continuous range in north-eastern Europe, including Fennoscandia , the Baltic states,
eastern Poland and northern Ukraine.
Flight Period
May to August, peaking in May but already rare in July.
Behavior
It can be hard to localize even in habitats where it is plentiful. Look for it low, down among and between tufts out in water-rich marches or reed beads where they fly just above the water surface. As opposed to many other Coenagrion species C. armatum is rarely seen flying over land.
Conservation Status
Similar Species
Ischnura elegans, Coenagrion pulchellum
External Links
Genus: Coenagrion
Coenagrion is a genus of damselflies in the family Coenagrionidae, commonly called the Eurasian Bluets (although three species are found in North America). Species of Coenagrion are generally medium-sized, brightly coloured damselflies.
Identification
Males are small blue damselflies with black markings. The blue areas may be partly greenish or whitish. Females have more extensive black markings, and are more often green or brownish. A damselfly with plain pterostigmas, with roundish postocular spots, with antehumeral stripes narrower than the black line below it, and with two short black lines on the thorax sides, will in most cases belong to Coenagrion.
Separation from other genera
Enallagma normally have antehumeral stripes wider than the black line below them and just one short black line on the thorax side. Ischnura males have bi-coloured pterostigma. Enallagma and Ischnura females have a vulvar spine. Erythromma species are darker, with reduced or no postocular spots, and males have red or all-blue eyes, whereas eyes of Coenagrion are blue with dark caps. The blue Erythromma lindenii is very similar, but differs in many details, like wider antehumeral stripes, an all-black upperside to S2 and a shorter 'tail-light' positioned further at the tip of the abdomen.
Behaviour
Males typically fly low among or along riparian vegetation. They rarely venture far from water. MAles and females in tandems often oviposit in concentrations on floating vegetation. The male often holds a conspicuous upright posture when in tandem with the female.
Family: Coenagrionidae
The insect family Coenagrionidae is placed in the order Odonata and the suborder Zygoptera. The Zygoptera are the damselflies, which although less known than the dragonflies, are no less common. More than 1,300 species are in this family, making it the largest damselfly family. The family Coenagrionidae has six subfamilies: Agriocnemidinae, Argiinae, Coenagrioninae, Ischnurinae, Leptobasinae, and Pseudagrioninae.
This family is referred to as the narrow-winged damselflies or the pond damselflies. The Coenagrionidae enjoy a worldwide distribution, and are among the most common of damselfly families. This family has the smallest of damselfly species. More than 110 genera of the family Coenagrionidae are currently accepted.
The family was named by William Forsell Kirby in 1890. The name may be derived from Greek coen meaning shared or common and agrio meaning fields or wild.