Big swell maiden
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Great spring maiden ( Cordulegaster heros ) |
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| Cordulegaster heros | ||||||||||||
| Theischinger , 1979 |
The great spring maiden ( Cordulegaster heros ) is a species of the spring maiden within the dragonflies , which is common in southern Europe. The species mainly lives in the area of springs, small streams and rivers and is threatened by the decline in their habitats.
features
The great spring maiden reaches a body length of about 10 centimeters and has a wingspan of about 12 centimeters. Outwardly, this type of swelling damsel is similar to the striped swelling damsel ( Cordulegaster bidentata ) and two- striped swelling damsel ( Cordulegaster boltonii ), but the yellow area of the drawing is more extensive and on the 7th abdominal segment the big swelling damsel has a wider transverse band than on the 6th abdominal segment while in C. . bidentata and C. boltonii the transverse bars are roughly the same width.
distribution
The big spring damsel is common in central and southern Europe. The distribution area extends from Austria and Slovakia via Hungary and Slovenia to the Balkans , where it can be found as far as Bulgaria , Albania and most of Greece . The eastern limit of distribution in Romania is not known, the area probably extends to Ukraine . The main area of distribution is in the Balkans, in Central Europe the species only occurs as islands due to the specific habitat requirements.
Way of life
This type of dragonfly occurs in small, shady streams and their springs, mostly in tiny spring rivulets and small rivers with sandy-gravelly bottoms. It can be common locally, but due to the special habitat requirements, it is very isolated and especially in higher mountain areas. In Austria it prefers larger and wider brooks than the two-striped spring damsel, with which it can also perform syntopically .
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The mating and oviposition happens as with the two-striped swell maiden. Larval development can take four to five years. The larvae live in calm areas of the streams with shallow water, whereby a preferred flow speed of less than six centimeters per second and an average water depth of 5.6 centimeters with coarse substrate was determined for Austria. They live almost completely buried in the stream sediment. Basically poor soils or stretches of water with a low oxygen content are avoided. The larvae can easily survive the short-term drying out of a body of water, but they do not survive in bodies of water with longer periods of drying out.
The flight time in years with average weather is between June and August. The emergence takes place in the area of wooded banks, the larvae move an average of 300 centimeters from the water and seek a suitable place at heights of about 150 centimeters on average. The dragonflies mature in the near and distant environment and live there for about two weeks, after which they return as sexually mature animals to the waters of hatch to mate. After mating, the female looks for flat overflowing stream sections with a fine detritus layer in order to pierce the eggs into the stream sediment with the help of her ovipositor .
Systematics
The big spring damsel is an independent species of the genus Cordulegaster within the spring damsel (Cordulegastridae). It was developed in 1979 by the Austrian entomologist Günther Theischinger together with the two subspecies C. h. heros and C. heros pelionensis scientifically described .
Danger
The Große Quelljungfer is listed in the IUCN Red List as a type of warning list ("near threatened"). The classification is justified by the strong islanding and fragmentation of the population as well as the declining quality and destruction of potential habitats in Southeast Europe. The main threat comes from the loss of their habitats, with global climate change leading to increased drying of streams and rivers as a result of the lack of precipitation and an increase in water abstraction for irrigation purposes . The destruction of forest areas through deforestation and forest fires also contribute to the drying up of rivers and the loss of habitats.
The species is listed in Appendices II and IV of Directive 92/43 / EEC on the conservation of natural habitats and wild animals and plants and is thus protected. This also means that their habitats should not be changed. In some countries, however, this is not respected, for example in Greece, where springs are regularly used to draw water to irrigate fields.
supporting documents
- ↑ Gerhard Jurzitza: The Kosmos dragonfly guide . Franckh-Kosmos Verlags GmbH & Co., Stuttgart 2000; P. 167. ISBN 3-440-08402-7 .
- ↑ Cordulegaster heros on libellenwissen.de; accessed on May 17, 2020.
- ↑ a b c d e f g h Cordulegaster heros in the Red List of Endangered Species of the IUCN 2010. Posted by: J.-P. Boudot, 2009. Retrieved May 17, 2020.
- ↑ a b c d e f Iris Fischer, Andreas Chovanec: Assessment of the state of preservation of the Großer Quelljungfer, Cordulegaster heros (Theischinger, 1979), in the Natura 2000 area Lainzer Tiergarten. 2017 ( full text ).
- ↑ Günther Theischinger: Cordulegaster heros sp. nov. and Cordulegaster heros pelionensis ssp. nov., two new taxa of the Cordulegaster boltoni (Donovan) complex from Europe (Anisoptera: Cordulegasteridae). Odonatologica 8 (1), 1979; Pp. 23-38.
Web links
- Cordulegaster heros inthe IUCN Red List of Threatened Species 2009.4. Posted by: Boudot, J.-P., 2009. Retrieved February 18, 2014.