Spurge Bark Owl

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Spurge Bark Owl
Acronicta euphorbiae.male.jpg

Spurge Owl ( Acronicta (Viminia) euphorbiae )

Systematics
Superfamily : Noctuoidea
Family : Owl butterfly (Noctuidae)
Subfamily : Acronictinae
Genre : Acronicta
Subgenus : Viminia
Type : Spurge Bark Owl
Scientific name
Acronicta (Viminia) euphorbiae
( Denis & Schiffermüller , 1775)
Spurge Owl caterpillar ( Acronicta euphorbiae )

The milkweed bark owl ( Acronicta euphorbiae ) or milkweed owl is a butterfly ( moth ) from the family of the owl butterflies (Noctuidae). It is very closely related to the sand heather bark owl ( Acronicta cinerea ). Some authors even deny the independence of the two species until recently.

features

The moths reach a wingspan of about 33 to 38 millimeters. The ground color of the fore wings is usually light gray; however, there are also very dark specimens. The basic color varies greatly depending on climatic and ecological factors. The inner and outer transverse lines are clearly drawn, the outer transverse line strongly jagged. The flaws are also usually clearly developed. A basal line is indistinct or missing entirely. The apex of the forewings is slightly pointed.

The hind wings are white in the males, gray in the females. There is an indistinct center line and a discal spot.

The egg has the shape of a flat, somewhat irregular cone with the tip cut off. The surface is covered with fine, irregular longitudinal ribs. The egg is initially yellowish, later black-brown with red dots and a black-brown row of dots around the egg.

The basic color of the caterpillars is usually blackish, with dark, hairy warts and yellowish or red side stripes. There are usually large, white or yellow triangular spots above them. There is a yellow-red, transverse back spot above the second segment. The head is black with a white angle. The adult caterpillar is up to 36 mm long.

The doll is colored black-brown. There are many short, straight bristles on the cremaster .

Similar species

The milkweed bark owl is very similar to the sand heather bark owl ( Acronicta cinerea ), if there are two species at all. The wingspan is of the same order of magnitude, but the sand heather bark owl is somewhat smaller on average. The apices of the forewings are more pointed in A. euphorbiae and the basic color is usually a little lighter. The outer transverse line is more jagged and the transverse lines and blemishes are drawn more clearly and with more contrast. A determination of the moths based only on the color and the drawing of the wings is not possible. This requires a genital examination of the butterflies. Probably the place of discovery is also more meaningful, since the distribution areas are probably mutually exclusive. Since the caterpillars of the two species differ very clearly, a clear allocation by means of breeding is also possible. The caterpillars of A. euphorbiae have a yellow-red dorsal spot on the second segment and yellow-red side stripes.

The other bark owls are also often very similar. They differ as follows:

  • Golden-haired bark owl ( Acronicta auricoma ), with very clear, almost circular and black-edged ring marks and dark welts.
  • Large-headed bark owl ( Acronicta megacephala ), with coarsely pollinated forewings and a clearly lightened area between the kidney blemish and the outer transverse line.
  • Maple bark owl ( Acronicta aceris ), with very light gray and scarce-colored fore wings and much larger butterflies.
  • Heath bark bark owl ( Acronicta menyanthidis ), with whitish-gray forewings , very small ring flaws without a center and with a dark welt.

Geographical distribution and habitat

The milkweed bark owl is common in Europe south of a line that stretches from northern Scotland, northeastern Netherlands / border with northwestern Germany, southeast through the northern Czech Republic, southern Poland, across Ukraine and southern Russia to the Urals Mountains .

The animals prefer to live in the hill country, on warm, sunny slopes, grassy heather areas and forest edges. In the Alps, they rise to over 2500 meters.

Way of life

The milkweed bark owl forms two generations a year. The moths of the first generation fly from April to June, those of the second generation from July to September. They are nocturnal and also visit artificial light sources . The first generation caterpillars are found in August and September, those of the second generation mainly in June. They feed on the leaves of many different plants. These include: cypress spurge ( Euphorbia cyparissias ), as well as birch ( Betula ), grouse ( Ononis ), bilberry ( Vaccinium myrtillus ), yarrow ( Achillea ), dock ( Rumex ), mugwort ( Artemisia ) and others. The pupa hibernates.

Danger

The species occurs in different frequencies in Germany and is listed in category 3 (endangered) on the Red List of Endangered Species . However, the situation is very different in the individual federal states. In Saarland it is already extinct, in Saxony-Anhalt it is threatened with extinction. It is seriously threatened in Baden-Württemberg, Lower Saxony, Saxony and Saxony.

swell

Individual evidence

  1. ↑ a b Red List
  2. ↑ a b Fibiger et al. (2009: p. 51/2)
  3. ↑ Heiko Bellmann : The new Kosmos butterfly guide. Butterflies, caterpillars and forage plants. Franckh-Kosmos, Stuttgart 2003, ISBN 3-440-09330-1 .
  4. ^ A b Walter Forster , Theodor A. Wohlfahrt : The butterflies of Central Europe. Volume 4: Owls. (Noctuidae). Franckh'sche Verlagshandlung, Stuttgart 1971, ISBN 3-440-03752-5 .
  5. ↑ Ebert et al. (1997: pp. 42–47)
  6. ↑ Federal Agency for Nature Conservation (Ed.): Red List of Endangered Animals in Germany. Landwirtschaftsverlag, Münster 1998, ISBN 3-89624-110-9

literature

  • Günter Ebert (Ed.): The butterflies of Baden-Württemberg . Volume 6, Nachtfalter IV. Ulmer Verlag, Stuttgart 1997, ISBN 3-8001-3482-9 .
  • Michael Fibiger, László Ronkay, Axel Steiner & Alberto Zilli: Noctuidae Europaeae Volume 11 Pantheinae, Dilobinae, Acronictinae, Eustrotiinae, Nolinae, Bagisarinae, Acontiinae, Metoponiinae, Heliothinae and Bryophilinae. 504 pp., Entomological Press, Sorø 2009, ISBN 978-87-89430-14-0 .

Web links

Commons : Spurge Owl  - Album with pictures, videos and audio files