Slender vials

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Slender vials
Horseshoe Damselfly (Coenagrion puella), adult male

Horseshoe Damselfly ( Coenagrion puella ), adult male

Systematics
Class : Insects (Insecta)
Subclass : Flying insects (Pterygota)
Order : Dragonflies (Odonata)
Subordination : Dragonfly (Zygoptera)
Superfamily : Slender vial-like (Coenagrionoidea)
Family : Slender vials
Scientific name
Coenagrionidae
Kirby , 1890

The Coenagrionidae (Coenagrionidae) are a family of damselflies (Zygoptera) within the dragonflies (Odonata). It is the most species-rich family of the dragonflies and the second most species-rich of the dragonflies.

features

Front wing of a slender dragonfly, here an azure damsel ( Coenagrion pulchellum ). The pterostigma is relatively narrow, the wings are stalked on the thorax , in front of the nodus there are always only two anterior transverse veins.

The slender dragonflies are comparatively small dragonflies with a slender and elongated, almost needle-shaped abdomen. In contrast to those of other dragonflies, the legs are relatively short. The range of color variations extends across the entire color spectrum, sometimes with bright, conspicuous colors and attractive, brightly colored color combinations, whereby a sexual dimorphism with more intensely colored males is not unusual. Metallic colors, on the other hand, only occur in a few species.

In the middle of the upper side of the front body ( thorax ) there is typically a dark median stripe, which is followed on each side by a light, colored ante-humeral stripe and then a darker humeral stripe. The width of these stripes is species-specific, the light-colored ante-humeral stripe can also appear broken up in some species or be completely absent. The side and underside of the thorax, on the other hand, are mostly without drawing. The abdomen usually has a pattern typical of the species, although similar elements that are repeated in different species can be found in almost all genera. However, there are also slender vials without any drawing of the abdomen, as well as those with an almost completely blackened abdomen. Especially in the case of the latter, there is a noticeably shining "tail light" due to the non-drawing, colored rear abdominal segments.

The abdomen of the females is much stronger than that of the males, as the egg-producing organs are located here. Usually the last abdominal segments appear additionally thickened by a clearly developed laying apparatus . The head and thorax drawing of the females mostly corresponds to that of the males, the drawing of the abdomen, on the other hand, is often different and usually more extensive on the upper side. The females of some species appear in different color morphs; There androchrome, male-colored, chrome or straight, female-colored imagines .

In contrast to the relatively complex wing veining of the large dragonflies and the magnificent dragonflies , the wing structure of the slim dragonflies is simple. The fore and hind wings are, as with all small dragonflies, built more or less the same. The wings, which are generally uncoloured, begin with a stalk on the thorax; the length of the shaft is different depending on the subfamily. As usual in the superfamily of the Coenagrionoidea , there are always two antenodal transverse veins in front of the nodus. The postnodal transverse veins merge directly into the transverse veins running through the width of the wing. The pterostigma on the front of the wing tips is never wider than one, at most one and a half, of the cells below. The cells in the middle of the wing formed by the veining of the wing are mostly rectangular; towards the lower outer edge they become more polygonal and smaller. At rest, the wings are almost always folded over the abdomen.

The basic color of the dragonflies is often exceeded by the bright colors of the widely spaced compound eyes . The upper part of the eyes appears darker and less colored, sometimes almost black, so that an optical central division results. The subfamily Argiinae is an exception , in which the horizontal separation is not so clear. The front of the head, i.e. the labrum , anteclypeus and clypeus , are often lighter than the rest of the head, and most species have clearly developed colored postocular spots, which are often connected to one another by a line.

distribution

Horseshoe azure damsel ( Coenagrion puella ) laying eggs

The slender vials are common worldwide. In Central Europe the dragonflies are the most species-rich family of the dragonflies, with the genus of the azure damsel being the most species. Mostly open ponds and moors are populated. Outside Europe, the slender dragonflies also use the banks of larger rivers as a habitat, but other dragonfly families usually dominate there, while the slender dragonflies can form populations with a large number of individuals on still waters .

Way of life

The mating corresponds to that of other dragonflies. With the formation of the mating wheel, mating takes place, after which the female releases the connection and the pair, still coupled, goes to lay eggs. This is usually done in pairs, in that the male remains anchored with the cerci on the pronotum of the female, while the female lays the eggs in floating parts of the plant. Either the male is buzzing freely over the female with his legs drawn up, or he sits above or in front of the partner on accessible parts of the plant. Females of the Ischnura species always lay the eggs alone. Often the females also completely submerge to lay their eggs. In these cases, the male usually loosens the connection or at least remains with the thorax above the surface of the water.

Systematics

Mortonagrion hirosei , male - subfamily Agriocnemidinae
Argia extranea , male - subfamily Argiinae
Cup damsel ( Erythromma lindenii ), female - subfamily Coenagrioninae
Great pitch dragonfly ( Ischnura elegans ), female - subfamily Ischnurinae
Ceriagrion glabrum , male - subfamily Pseudagrioninae

The following overview shows all taxa up to the level of the subfamily . At the species and genus level, however, only the European representatives of the slender vials are shown. Complete lists can be found in the corresponding subfamily or generic articles.

Naming

Due to a misleading definition by Johann Christian Fabricius , the generic name Agrion was used in the following period for both the Calopteryx and the Coenagrion genera. This problem was not resolved until the 1950s and the aforementioned generic names became established. In this episode, the family name Coenagrionidae, based on the genus Coenagrion , became established. In terms of nomenclature, however, this is incorrect and should correctly be called "Coenagriidae", but has been retained so far. The German trivial name is based on the slim body shape.

swell

literature

  • Jill Silsby: Dragonflies of the World . Smithsonian, Washington 2001, ISBN 1-56098-959-9 .
  • Dennis Paulson: Dragonflies and Damselflies of the West, Princeton Field Guides , Princeton University Press, New Jersey 2000, ISBN 978-0-691-12281-6 .
  • Klaas-Douwe B. Dijkstra: Field Guide to the Dragonflies of Britain and Europe . British Wildlife Publishing, Gillingham 2006, ISBN 0-9531399-4-8 .
  • Klaus Sternberg, Rainer Buchwald (ed.): The dragonflies of Baden-Württemberg. Volume 1: General part, dragonflies (Zygoptera). Verlag Eugen Ulmer, Stuttgart 1999, ISBN 3-8001-3508-6 .
  • Heiko Bellmann: The Kosmos dragonfly guide. Determine the species of Central Europe with certainty , Franckh-Kosmos-Verlag, Stuttgart 2007, ISBN 978-3-440-10616-7 .
  • Gerhard Jurzitza: The Kosmos dragonfly guide . The species of Central and Southern Europe , Franckh-Kosmos-Verlag, Stuttgart 2000, ISBN 3-440-08402-7 .

Individual evidence

  1. ↑ a b c d Dennis Paulson: Dragonflies and Damselflies of the West , p. 73.
  2. ^ Jill Silsby: Dragonflies of the World , pp. 106 ff.
  3. ↑ Heiko Bellmann: Der Kosmos-Dragonfly Guide , p. 53.
  4. ↑ a b c Coenagrionidae . In Sternberg, Buchwald: The dragonflies of Baden-Württemberg. Volume 1 , p. 215.
  5. ↑ Heiko Bellmann: Der Kosmos-Libellenführer , p. 23.
  6. ↑ Coenagrionidae  ( page no longer available , search in web archives )  Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice. in taxonomy [Odonata]. Posted by Dr. Jan van Tol, naturalis, Nationaal Natuurhistorisch Museum. Retrieved March 22, 2011.@1@ 2Template: Dead Link / www.odonata.info  
  7. ^ Martin Schorr, Dennis Paulson: World Odonata List. Update from January 25, 2011 ( download ).

Web links

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