Violet sun pointer
| Violet sun pointer | ||||||||||||
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Violet sun pointer ( Trithemis annulata ), male |
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| Trithemis annulata | ||||||||||||
| ( Palisot de Beauvois , 1805) |
The violet sun pointer ( Trithemis annulata ) is sometimes also referred to as the violet sun indicator or red-violet sail dragonfly , is a large dragonfly species and belongs to the family of the sail dragonflies (Libellulidae).
features
The violet sun pointer has an average wingspan of six to seven centimeters. The male is almost entirely red. The transverse veins of the wing leading edges and also other veins and the pterostigma are conspicuously red. The abdomen of colored males appears bright red-violet through a thin layer of wax. The females and also the young males are yellow-brown, except for a fine, black back line and narrow, black rings. The back part of the last three segments is also colored black. The hind wings of males and females each show a large, orange-yellow basal spot.
Similar species
All Sympetrum species, especially species with yellow wing spots and / or red veins, such as the early darter ( Sympetrum fonscolombii ).
Way of life
The males like to sit on stones and plants near the shore. The adults fly from April to November.
Occurrence
The undemanding, invasive species lives in standing and flowing waters in North Africa , West Africa, West Asia and, for a few decades, also in southern Europe , especially on the Iberian Peninsula. It is currently expanding clearly to the north and west. It now also occurs in southern France , where the Rhône valley is already populated.
Reproduction
The pairing takes place within a few seconds in flight. The subsequent oviposition takes place in a single flight under the guard of the male. With rocking movements, the female flies around 71 seconds long, just above the surface of the water and taps the end of her ( abdomen ) into the water about every 2.5 seconds. On average, around 924 eggs are released. The male circles around the female and drives away any approaching competitor. If the female is disturbed by a competitor, it flies up and away. The eggs are green and about 0.41 × 0.25 mm in size. As a rule, the larvae go through 11 stages. The period between egg-laying until the dragonfly is able to fly is an average of 52 days. This means that several generations are possible in the course of a year.
literature
- Gerhard Jurzitza: The Kosmos dragonfly guide . Franckh-Kosmos Verlag, Stuttgart 2000, ISBN 3-440-08402-7 .
- Hansruedi Wildermuth, Andreas Martens: Pocket dictionary of dragonflies in Europe . Quelle & Meyer Verlag, Wiebelsheim 2014, ISBN 978-3-494-01558-3 .
Web links
- Trithemis annulata inthe IUCN 2013 Red List of Threatened Species . Posted by: Boudot, J.-P., Clausnitzer, V., Ferreira, S., Suhling, F., Dijkstra, K.-DB, Schneider, W. & Samraoui, B., 2012. Accessed September 11 2013.
- LibellenWissen.de