Blue gentian

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Blue gentian
Bluebird (Phengaris alcon)

Bluebird ( Phengaris alcon )

Systematics
Class : Insects (Insecta)
Order : Butterflies (Lepidoptera)
Family : Bluebirds (Lycaenidae)
Subfamily : Polyommatinae
Genre : Phengaris
Type : Blue gentian
Scientific name
Phengaris alcon
( Denis & Schiffermüller , 1775)

The Phengaris Alcon ( Phengaris alcon , syn. Maculinea alcon ), including Little Moorbläuling called, is a butterfly ( butterfly ) from the family of Gossamer (Lycaenidae). The specific epithet is derived from Alcon, a Greek shepherd name.

features

The moths reach a wingspan of 32 to 36 millimeters. They have blue, slightly whitish, with a dark edge (males) or dark brown, at the base of the wing slightly dusted blue (females), the edge of which is fringed white. The undersides of the wings are light gray and have several black, white-bordered spots. They look very similar to the blue gentian ant ( Phengaris rebeli ) and, like this species, develop variable wing colors depending on their distribution area and altitude. Therefore, they are difficult to distinguish from one another.

The caterpillars are about 15 millimeters long. They are light reddish or yellowish in color and have a black head. The entire color appears somewhat darkened.

Similar species

Synonyms

  • Maculinea alcon
  • Lycaena alcon

Occurrence

They occur from northern Spain through France , Central and Eastern Europe to Siberia and Mongolia . To the north they are missing beyond the south of Sweden . To the south, the distribution limit is northern Italy or the middle of the Balkan Peninsula . In Germany you can only find them in the foothills of the Alps and in places as far as the plains of northern Germany, such as B. on the Lüneburg Heath . They are very rare and have already disappeared in many places. The blue gentian ant is local in the lowlands and mountains up to 1000 meters in wetlands such as z. B. to meet wet meadows, moors and heaths ; they are especially found in the floodplains of rivers .

Flight time

They fly in one generation from mid-June to mid-August, but mostly until the end of July.

Way of life

The moths live in the immediate vicinity of gentian plants.

Egg-laying female
Lung gentian eggs ( Gentiana pneumonanthe )
Gentian ant blue eggs

Food of the caterpillars

The caterpillars feed on lung gentian ( Gentiana pneumonanthe ), in the Alpine region or the Alpine foothills they also occasionally eat swallowwort gentian ( Gentiana asclepiadea ).

development

The females lay several of their eggs loosely distributed on the buds, rarely also on the leaves and stems, of the forage plants. The eggs are white and slightly flattened. They are clearly visible on the plants and give the appearance of a fungal attack . The caterpillars eat a while hatching into the plant inside and feed on the ovary of the seeds and their equipment. After two or three molts, they eat their way outside and fall to the ground. Due to the imitation of scents and the chemical surface structure of their outer skin, they are picked up by two different species of knot ants (forest knot ant, Myrmica ruginodis and red garden ant, Myrmica rubra ) and carried into their nests. Because the caterpillars imitate the skin of their host larvae, the ants are fooled by the parasitic butterflies: They mistake the caterpillars for their own larvae . They live in their nests until the following spring and are fed preferentially by them. They pupate inside the nest. After hatching, the butterflies do not have much time to flee because they do not have any scents that protect them from the ants. For the affected species of ants, the parasite infestation can lead to the colony shrinking, since the preferred feeding of the butterfly larvae endangers its own offspring. The caterpillars can in turn be attacked by the parasitic parasitic wasp Ichneumon eumerus within the ant burrow . Their females lay their eggs in the caterpillars, the hatching larvae then develop in the caterpillars and kill them.

Hazard and protection

  • Red list FRG: 2 (endangered). They are not only dependent on the presence of their forage plants, but also on large populations of knot ants in their vicinity. In addition, they are severely endangered by the drainage of wetlands, but also by climatic fluctuations associated with dry periods.

Individual evidence

  1. ^ Arnold Spuler: The butterflies of Europe . tape 1 . E. Schweitzerbartsche Verlagbuchhandlung, Stuttgart 1908, p. 68 .
  2. ↑ a b c d e f g Heiko Bellmann : The new Kosmos butterfly guide, butterflies, caterpillars and forage plants . Franckh-Kosmos, Stuttgart 2003, ISBN 3-440-09330-1 , p. 150 .
  3. ↑ a b c d e Tom Tolman, Richard Lewington: The butterflies of Europe and Northwest Africa . Franckh-Kosmos, Stuttgart 1998, ISBN 3-440-07573-7 , p. 89 .
  4. ^ List of host ant species for blue ant species
  5. ^ David Nash: The Ant and the Butterfly. In: Science 319, 2008, p 88 (See also Livia Rasche: The cuckoo in the butterfly dress. In: wissenschaft.de. January 4th 2008, accessed on September 8, 2019 . )
  6. ^ Peter Jacoby: Chemically initiated civil war. In: Chemie in our Zeit 36, No. 4, 2002, p. 212, doi : 10.1002 / 1521-3781 (200208) 36: 4 <212 :: AID-CIUZ212> 3.0.CO; 2- # .

literature

  • Zdenék Fric, Niklas Wahlberg, Pavel Pech and Jan Zrzavý: Phylogeny and classification of the Phengaris – Maculinea clade (Lepidoptera: Lycaenidae): total evidence and phylogenetic species concepts. Systematic Entomology, 32: 558-567, Oxford 2007 doi : 10.1111 / j.1365-3113.2007.00387.x
  • Lionel G. Higgins, Norman D. Rilley: Die Tagfalter Europas und Nordwestafrikas , 1971, (A Field Guide to the Butterflies of Britain and Europe), Verlag Paul Parey, 1970, ISBN 3-490-02418-4 .
  • Butterflies. 2. Special part: Satyridae, Libytheidae, Lycaenidae, Hesperiidae . In: Günter Ebert, Erwin Rennwald (eds.): The butterflies of Baden-Württemberg . 1st edition. tape 2 . Ulmer, Stuttgart (Hohenheim) 1991, ISBN 3-8001-3459-4 .
  • Manfred Koch : We determine butterflies. Volume 1: Butterfly. 4th enlarged edition. Neumann, Radebeul / Berlin 1966, DNB 457244224 .

Web links

Commons : Blue Gentian  - Album with pictures, videos and audio files