Scarlet dragonfly
| Scarlet dragonfly | ||||||||||||
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Ceriagrion tenellum , males and females (f. "Typica") |
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Ceriagrion tenellum | ||||||||||||
| ( de Villers , 1789) |
The scarlet dragonfly ( Ceriagrion tenellum ), also known as the tender ruby dragonfly or late adonis dragonfly , is a species of small dragonfly from the family of the slender dragonfly (Coenagrionidae). In addition to the early adonis dragonfly ( Pyrrhosoma nymphula ), the scarlet dragonfly is the only red-colored dragonfly species in Central Europe. However, it is more closely related to the dwarf dragonfly ( Nehalennia speciosa ) than to Pyrrhosoma .
features
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The length of the abdomen ( abdomen ) of the small and delicate species is 22.5 to 27.2 millimeters in the males. The females are slightly larger and reach between 23 and 29.6 millimeters. The species also shows strong differences between the sexes, so-called sexual dimorphism . The male is bright red except for the brownish or bronze-green thorax and the top of the head including the 0.5 to 0.6 millimeter long wing mark ( pterostigma ) and the eyes . In particular, the legs are also red to ocher yellow, which allows a demarcation from the early Adonis dragonfly, which has black legs. The hind wings reach 15 to 19 millimeters in length.
Four color variants are distinguished in the female. There is a similarly colored (homochromic) expression to the male, this is called " erythrogastrum " because of the predominantly red color . The form " typica " has a partially black abdomen color, which is limited by red sections on the beginning and end segments S1-3 and S9-10. The complexion is cream-colored instead of red and the complex eyes appear in a dull green below. Like the postclypeus, the lower half of the lower lip is metallic black-green. In the dark form of " melanogastrum ", the upper side of the abdomen and the face are predominantly black in color. Finally, a form " intermedium " is described which combines specimens with different red and black components between the two aforementioned color morphs. The facial coloring here is the same as that of "typica".
Way of life
The adults' flight time is from May to September. The copulation in the mating wheel takes about 40 minutes. The subsequent egg laying on floating parts of the plant protruding from the water is carried out in tandem. Rushes ( Juncus ) are particularly popular for this . Usually around 30 eggs are laid in one place. After about 10 minutes the tandem changes location. However, unlike early adonis dragonflies , scarlet dragonflies do not dive into the water. The larvae usually take a year to develop , but can take two years in cooler areas such as England.
Habitat
In the northwest of the area in particular, bogs and heather ponds with peat moss are preferred. But also sloping moors with rust red ( Schoenus ferrugineus ) and black copfried ( Schoenus nigricans ) are settled. The nutrient supply of the waters is mostly oligo- to mesotrophic . In transitional moors, the species likes to colonize areas between closed meadows made of rush edge ( Cladium mariscus ) and meadows with stiff sedge ( Carex elata ) that are permanently flooded.
Spread and endangerment
With a few exceptions, the Atlantic-Mediterranean species is found in almost all countries of Western Europe. While it only colonizes stagnant water in colder climes, rivers are also colonized in southern Europe. In Germany, the species has two separate areas: a large one in the northwestern lowlands (Lower Saxony, western North Rhine-Westphalia) and a small one on Lake Constance; in between it is completely absent. There are only a few stray finds in the northeastern German lowlands. In recent years the scarlet dragonfly has been able to expand its occurrence and is now only included in the "warning list" on Germany's current Red List (as of 2012) (previously it was considered "critically endangered"). The species is very rare in Switzerland and is classified as "critically endangered".
swell
literature
- Hans-Joachim Clausnitzer: Ceriagrion tenellum (de Villers, 1789). Pp. 54–57 in: T. Brockhaus, H.-J. Roland, T. Benken, K.-J. Conze, A. Günther, KG Leipelt, M. Lohr, A. Martens, R. Mauersberger, J. Ott, F. Suhling, F. Weihrauch & C. Wigalla (eds.): Atlas of the dragonflies of Germany. Libellula Supplement 14, 2015.
- Hans-Joachim Clausnitzer, Christa Clausnitzer, Rüdiger Hengst: On the ecology of Ceriagrion tenellum in the area of the northeastern limit of distribution in Lower Saxony (Odonata: Coenagionidae). Libellula 26, 2007 (1/2): pp. 19-34.
- Klaas-Douwe B Dijkstra: Field Guide to the Dragonflies of Britain and Europe. British Wildlife Publishing, 2006. ISBN 0-953-1399-4-8
- Gerhard Jurzitza: The Kosmos dragonfly guide . Franckh-Kosmos Verlags GmbH & Co., Stuttgart 2000, ISBN 3-440-08402-7 .
- Paul-A. Robert: Die Libellen (Odonaten) - Authorized translation by Otto Paul Wenger [p. 155f], Kümmerly & Frey, Geographischer Verlag, Bern 1959.
Individual evidence
- ↑ J. Ott, K.-J. Conze, A. Günther, M. Lohr, R. Mauersberger, H.-J. Rohland & F. Suhling: Red list and total species list of dragonflies in Germany with analysis of responsibility, third version, as of early 2012 (Odonata) . Libellula Supplement 14, 2015: 395-422.
Web links
- Species protection sheet for the late Adonis dragonfly (PDF file; 323 kB)