Hawk dragonfly
| Hawk dragonfly | ||||||||||||
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Hawk dragonfly ( Cordulia aenea ), male |
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Cordulia aenea | ||||||||||||
| ( Linnaeus , 1758) |
The falcon dragonfly or common emerald dragonfly ( Cordulia aenea ) is a species from the family of the falcon dragonflies (Corduliidae). The epithet of the scientific species name is pronounced in four syllables and stressed on the second syllable ( a- e -ne-a ). It is the eponymous species of the Corduliidae family.
features
The species is similar in appearance to the representatives of the genus Somatochlora (emerald dragonflies), but has a monochrome green forehead ( somatochlora with yellow spots). The falcon dragonfly becomes five to five and a half centimeters long and has a wingspan of 7.5 cm. Their wings are built differently: The hind wings have a broadened base. The body shines metallic-green to copper-colored, the eyes are green. In the males, the abdomen is widened like a club at the rear, with the greatest width being reached at the 7th and 8th segments. Another difference to the similar shiny emerald dragonfly ( Somatochlora metallica ) is that the females have a cylindrical abdomen without a noticeably protruding laying tube. Cordulia also looks a bit more hairy on the thorax and has an earlier flight time.
distribution
The falcon dragonfly is a Euro-Siberian element of fauna; to the north it extends in Scandinavia to 68 ° 55 'north latitude, in Siberia to about 70 ° nB. To the east it extends over Siberia to Japan, to the west it reaches the south of Ireland and Great Britain. The species is absent on the Iberian Peninsula and in the Mediterranean countries. Warm regions are generally avoided or at most populated in mountainous areas. It is widespread in Germany, although the frequency can vary greatly depending on the region. Overall, Cordulia aenea is a little more common here than Somatochlora metallica , but in northern Germany it is the other way around.
Habitat and way of life
The dragonfly inhabits smaller, herbaceous, preferably dystrophic lakes and ponds as well as extensively managed fish ponds that offer certain habitat structures. Mainly alluvial forest waters are settled.
The hatching period begins in Central Europe at the beginning of May (sometimes at the end of April) and has its peak a little later (May / June). The main flight time is then in the second half of June (lowlands) or in July (mountainous regions). The last animals are still on their way in mid-August (occasionally September). The males usually fly restlessly patrolling along the waterfront and keep shaking in the air. They are looking for females and driving competing males out of their territory. The females are very shy and only come to the water to reproduce, where they hide in the bank vegetation. To lay their eggs , they hover and throw the eggs into the water in small clumps with rocking movements.
The hatching larvae develop in the eggs after around three weeks. These have remarkably long legs and a somewhat flattened, broad abdomen; the dorsal spines are low. They usually spend two years in the water before they metamorphose into the imago . The subspecies Cordulia aenea amurensis can also need five years for the aquatic larval phase in Siberia.
photos
Male in side profile
Mating wheel
Newly hatched imago with exuvia
In flight
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literature
- Heiko Bellmann: The cosmos dragonfly guide. Franckh-Kosmos, Stuttgart 2007, ISBN 978-3-440-10616-7
- Klaus Sternberg, Bertrand Schmidt: Cordulia aenea (Linnaeus, 1758), falcon dragonfly. Pp. 209–218 in: Sternberg / Buchwald (ed.): Die Libellen Baden-Württemberg , Volume 2, Ulmer Stuttgart 2000, ISBN 3-8001-3514-0
Web links
- Cordulia aenea inthe IUCN 2013 Red List of Threatened Species . Posted by: Clausnitzer, V., 2007. Retrieved October 23, 2013.