Horseshoe Azure Maiden

from Wikipedia, the free encyclopedia
Horseshoe Azure Maiden
Horseshoe Azure Damselfly (Coenagrion puella), ♂

Horseshoe Azure Damselfly ( Coenagrion puella ), ♂

Systematics
Subordination : Dragonfly (Zygoptera)
Superfamily : Coenagrionoidea
Family : Dragonfly (Coenagrionidae)
Subfamily : Coenagrioninae
Genre : Azure Maiden ( Coenagrion )
Type : Horseshoe Azure Maiden
Scientific name
Coenagrion puella
( Linnaeus , 1758)

The horseshoe damsel ( Coenagrion puella ) is a species of dragonfly from the family of the slender dragonflies (Coenagrionidae). The horseshoe damsel is a small dragonfly with a wingspan of a maximum of five centimeters.

features

The horseshoe azure virgin reaches body lengths of 35 to 40 millimeters and is usually very slender, almost needle-shaped. The horseshoe azure maiden owes its name to the horseshoe-shaped black mark that can be found on the second abdomen segment of the male (Fig. 7). However, this also exists in similar species such as the bat azure virgin ( C. pulchellum ) in a similar form, in which the black drawing of the following abdomen segments is more extensive. In addition, the shape of the forceps on the last abdominal segment (Fig. 10) is used to correctly identify the males. The males are blue with black markings. In the case of the colored females, the black markings predominate, in the basic color they are mostly green (heterochrome females, picture 3), sometimes light blue (homoeochrome females, picture 4). Young specimens are milky pale in males and females (Fig. 5, 6). The females do not wear a “horseshoe” on the first abdominal segment, but a drawing reminiscent of a trophy (Fig. 8). However, the drawing also varies considerably and there is overlap with several other species. That is why the line in which the pronotum ends at the back is used to determine the type. In the horseshoe azure maiden, this is double-curved and mostly blue (Fig. 9). The shape of the pincer in the male and the shape of the pronotum in the female are constant features, as they have to "fit" exactly for the mating wheel (Fig. 14).

Way of life

The adults hatch between May and August and have a life expectancy of up to four weeks. Like most other dragonflies, the horseshoe damsel feeds on insects , which it usually catches in flight. When mating, the males grab the females with their abdominal forceps ( cerci ) below the head. To carry out fertilization, the two dragonflies form the so-called pairing wheel . The female takes the seeds from the male's seed pocket. The eggs are also laid in pairs in tandem. In this case, the female sits horizontally and the male rises up. The female pierces the eggs with her ovipositor into the aquatic plants . By laying eggs together, the male prevents the female from being fertilized by competitors. The eggs that are laid take between two and five weeks to become a larva.

Characteristics of the larva

The slender larva (Fig. 18) is pale brownish or greenish. It has three gill leaves at the end of the body (Fig. 20). In the late larval stages, the larva is about 1.5 cm long, the gill leaflets at least three millimeters. These are pointed, but do not run out like threads. The side veins branch off diagonally to the rear. On the sides they are covered with stiff bristles up to about the middle. The antennae of the larvae are made up of seven limbs, the base limb is not particularly long (Fig. 19, color falsified by air bubbles).

Larval development

The larvae are mostly found in standing, sometimes in flowing water. The larval period lasts about a year, with overwintering as a larva. The larvae hatch in southern Germany in late April or early May. The transformation into an imago mostly takes place in the late morning. The transformation until the Imago takes off takes between 30 minutes and three hours.

distribution

The species is distributed almost everywhere in Europe, but in Scandinavia it is only found in the south and is absent in Finland. It becomes rare where the July isotherm drops below 15 ° C. To the east it penetrates in the subspecies kocheri as far as Mongolia and western Siberia. In Central Europe it is one of the most common dragonfly species, but is less common in the mountains than in the plains due to climatic reasons.

media

Coenagrion puella schlupf1.JPG Coenagrion puella schlupf2.jpg Coenagrion puella schlupf3.jpg Coenagrion puella schlupf4.JPG Coenagrion puella schlupf5.jpg Coenagrion puella schlupf6.jpg Coenagrion puella schlupf7.jpg Coenagrion puella schlupf8.jpg Coenagrion puella schlupf9.jpg
Figure 1: Phases of the slip Image 2: video

literature

  • W. Stichmann, U. Stichmann-Marny, E. Kretzschmar: The great cosmos nature guide - animals and plants. Franckh-Kosmos Verlag, Stuttgart 1996, ISBN 3-440-09454-5 .
  • H. Bellmann: Observe dragonflies - determine. Naturbuch Verlag, Augsburg 1993, ISBN 3-89440-522-8 .
  • G. Jurzitza: The Kosmos dragonfly guide . Franckh-Kosmos Verlag, Stuttgart 2000, ISBN 3-440-08402-7 .
  • Buchwald Sternberg (ed.): The dragonflies of Baden-Württemberg. Volume 1, Ulmer, Stuttgart 1999, ISBN 3-8001-3508-6 , p. 278 ff

Web links

Commons : Horseshoe Azurmaid  - Album containing pictures, videos and audio files