Alder Arrow Owl

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Alder Arrow Owl
Alder Arrow Owl (Acronicta cuspis)

Alder Arrow Owl ( Acronicta cuspis )

Systematics
Order : Butterflies (Lepidoptera)
Superfamily : Noctuoidea
Family : Owl butterfly (Noctuidae)
Subfamily : Acronictinae
Genre : Acronicta
Type : Alder Arrow Owl
Scientific name
Acronicta cuspis
( Huebner , 1813)
Specimen of an alder arrow owl

The alder Gray Dagger ( Acronicta cuspis ), also alder wood moth , heathland-Gray Dagger or Gentiles-Gray Dagger is a butterfly ( moth ) from the family of cutworms (Noctuidae).

features

The moths have a wingspan of 37 to 45 millimeters. The basic color of the fore wings is gray, blue-gray or black-gray. The root line and the tornal line are clearly developed, and the inner and outer transverse lines are clearly drawn. In contrast, the middle shadow is usually only clearly visible at the front and rear edges. The hem line is practically undeveloped. Ring and kidney flaws are clearly visible, especially towards the short black line that lies between the two flaws. The fringes have narrow lines between the wing veins. The hind wings are gray in both males and females; they get darker towards the terms. The center line and the discal spot are indistinct; on the other hand the hemline is drawn in black. The fringes are light gray with internal lines. The underside of the wings is gray, with the front wings usually being kept a little darker. The discal spot and the median line are clearly visible on the undersides of the fore and hind wings. The head and thorax are colored gray.

The moths cannot be clearly distinguished from arrow owl ( Acronicta psi ) and the trident arrow owl ( Acronicta tridens ) only because of their external morphology .

The caterpillars have a black basic color, thin, short hairs and have a wide white-yellow back and white-gray side stripes and red horizontal lines on the sides. On the fourth segment there is a long, brown tuft of hair, on the eleventh segment a conical, black elevation.

The slender doll is colored black-brown with a blunt cremaster , which is circularly decorated with short, thorn-like bristles.

Similar species

The moths of the alder arrow owl ( Acronicta cuspis ), the arrow owl ( Acronicta psi ) and the moths of the trident arrow owl ( Acronicta tridens ) are very similar. The following are listed as distinguishing features:

  • The adults of A. cuspis and A. tridens are on average somewhat larger, but the absolute size range is almost the same.
  • The color nuances of the basic color differ slightly, A. cuspis often has a bluish tinge. The root line and the tornal line are very clearly developed. The hind wings of the male are dark gray with a relatively clear center line and discal spot. The hind wings of the other two species are white, with the exception of the border line (in A. tridens ) or black dust along the veins in A. psi .
  • The forewing of A. psi is by far the most variable as far as the basic color is concerned; this varies from white-gray to plain dark gray. The hind wing is blackish along the distal portions of the veining and the fringing line. In very dark forms, the hind wing of A. psi can be as dark as that of A. cuspis , but is less dusty.
  • In A. tridens, on the other hand, the fore wing is less variable, less marked and usually darker than in A. psi .
  • A. tridens is more common in more humid, moor-like biotopes.

Despite the differentiating features mentioned, a reliable determination is only possible through a genital examination of the butterflies. However, since the caterpillars of the three species mentioned differ very clearly, a clear allocation by means of breeding is also possible.

Geographical distribution and habitat

The species is widespread in Europe, but the range is highly fragmented. The populations in northern Spain and southwestern France as well as a population in Normandy are isolated from the Central European population by a wide corridor. This distribution area extends from north-east and east France and south-east France through Central Europe to the Ural Mountains; from there on via Siberia to the Russian Far East , North China, Korea and Japan. In the north the distribution area extends to Denmark, southern Sweden, the southern half of Finland and about 65 ° latitude across Russia to the Urals. In the south a population extends to central Spain, in Italy the occurrence is limited to northern Italy and the northern half of Sardinia. The southern border continues through the northern part of Croatia, southern Hungary and northern Romania into Ukraine (including the Crimean peninsula). Individual isolated occurrences are also known south of this border. Isolated occurrences have also been described from northwest Africa. The species is also found in Asia Minor, the Caucasus and Central Asia.

The animals prefer to live in alder trees, scrub and bog forests and bog heaths. In the Alps, they rise to an altitude of 2000 meters.

Way of life

The alder arrow owl forms one generation per year, the moths of which fly slightly differently from May to August regionally. The moths are nocturnal and come to artificial light sources and the bait .

The caterpillars are found from August to September. They feed on the leaves of various alder species, but also on birch ( Betula ), hazel ( Corylus ) and white berries ( Sorbus ). They live singly or gregariously on the food plants, often open on the leaf tops. Pupation takes place in a web mixed with leaves on the ground or in cracks in the trunk, where the pupa also overwinters.

Systematics

The species is put by Fibiger et al. (2009) to the subgenus Triaena Hübner, 1818, together with arrow owl ( Acronicta psi ) and the trident arrow owl ( Acronicta tridens ). No subspecies are listed.

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 in the individual German federal states is very different. It is already extinct in Thuringia , in Lower Saxony, North Rhine-Westphalia, Saarland and Saxony the species is threatened with extinction (Category 1), in Brandenburg, Hamburg, Rhineland-Palatinate and Saxony-Anhalt it is endangered (Category 2). Only in Bavaria, Baden-Württemberg and Mecklenburg-Western Pomerania is it "only" listed in category 3 (endangered).

swell

Individual evidence

  1. ↑ a b Red Lists
  2. ↑ a b c d e Fibiger et al., 2009, pp. 43/44.
  3. ↑ Walter Forster , Theodor A. Wohlfahrt : The butterflies of Central Europe. Volume 4: Owls. (Noctuidae). Franckh'sche Verlagshandlung, Stuttgart 1971, ISBN 3-440-03752-5 , p. 244.
  4. ↑ Arno Bergmann: The large butterflies of Central Germany. Volume 4/1: Owls. Distribution, forms and communities. Urania-Verlag, Jena 1954, DNB 450378373 , pp. 43-44.
  5. ↑ 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 5: Moths III (Sesiidae, Arctiidae, Noctuidae). Ulmer Verlag, Stuttgart 1997, ISBN 3-8001-3481-0 .
  • Michael Fibiger, László Ronkay, Axel Steiner, Alberto Zilli: Noctuidae Europaeae. Volume 11: Pantheinae, Dilobinae, Acronictinae, Eustrotiinae, Nolinae, Bagisarinae, Acontiinae, Metoponiinae, Heliothinae and Bryophilinae. Entomological Press, Sorø 2009, ISBN 978-87-89430-14-0 .

Web links

Commons : Alder Arrow Owl  - Collection of images, videos, and audio files