Trident arrow owl
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Trident arrows owl ( Acronicta tridens ) |
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| Acronicta tridens | ||||||||||||
| ( Denis & Schiffermüller , 1775) |
The trident arrow owl ( Acronicta tridens ), also known as the trident owl, is a butterfly ( moth ) from the owl butterfly family (Noctuidae).
features
The moths have a wingspan of 36 to 44 millimeters. The basic color of the forewings is gray, mostly dark gray and relatively uniform in color. The root line and tornal line are clearly developed, as are the inner and outer transverse lines. These are drawn in black and double. In contrast, the middle shadow can only be seen clearly at the front and rear edges, the hemline is indistinct. Ring flaws and kidney flaws are easy to recognize in the area of the intermediate flaw line. The fringes are white with narrow internural lines. The hind wings of the males are usually completely white, in some forms there is a black over-dusting of the veins in the distal parts of the veins. In females, the hind wings are gray at the base and darken towards the outer edge. The middle transverse line and the discal spot can only be seen indistinctly, but the border line is clearly drawn in black. The underside of the fore and hind wings is gray, with the underside of the fore wing slightly darker. Both lower sides have a central transverse line and a discal patch, the transverse line being weak on the underside of the hind wing. The head and thorax are colored gray.
The egg is very flattened and cone-shaped. The surface is covered with strong longitudinal ribs. It is light yellow in color with a red-brown spot in the middle and three other spots of the same color.
The black-gray, relatively long and slender caterpillars are relatively little hairy. The red-yellow stripe on the back is divided by a black center line. It has a short, black pin on the 4th segment on the back. The 11th segment has a black, red and yellow dotted elevation. The broad, yellow and white side lines are spotted with red. The head is black and gray.
The doll is red-brown with a bristle cremaster .
The moths of the alder arrows owl ( Acronicta cuspis ), arrows owl ( Acronicta psi ) and the moths of the trident arrows owl ( Acronicta tridens ) are very similar and can only be reliably differentiated by genital examinations . The following are listed:
- 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.
In contrast to the butterflies, the caterpillars of the species listed above can be easily distinguished.
Geographical distribution and habitat
The trident arrow owl is widespread in Europe. It is only missing in smaller areas in southern Spain and eastern Portugal, in Ireland and Scotland, in western Scandinavia (Norway with the exception of some occurrences in southern Norway), northern Scandinavia and northern Russia (roughly north of 65 ° latitude). It is also largely absent in southern Greece and the Greek islands. The species occurs outside Europe in northwest Africa, in Asia Minor, Cyprus, the Caucasus region , Israel, northern Iran, in Siberia to the Russian Far East , northern China, Korea and Japan.
It prefers forest edges rich in bushes, clearings, aisles, forest paths in warm mixed oak forests, but also moist alluvial forests. In the Alps it rises to 1500 m above sea level.
Way of life
The trident arctic owl forms two generations a year in Central Europe, the moths of which fly from early May to late June and mid-July to late August / early September. The moths are nocturnal and come to artificial light sources and the bait .
The caterpillars feed on the leaves of beeches ( Fagus ), oaks ( Quercus ), roses ( Rosa ), apples ( Malus ), Prunus , pears ( Pyrus ), white berries ( Sorbus ), birches ( Betula ), willows ( Salix ), Alder ( Alnus ) and ash ( Fraxinus ). Ebert et al. (1997) mention hawthorns ( Crataegus ) as a food plant for caterpillars. The caterpillar pupates in a web in autumn. The pupa hibernates.
Hazard and protection
The three-pronged arrow owl is a kind of advance warning in Germany. However, the situation in individual German federal states is clearly different. In Bavaria, Brandenburg, North Rhine-Westphalia, Saxony, Saxony-Anhalt and Thuringia, the species is classified as critically endangered (category 2), in Mecklenburg-Western Pomerania in category 3 (endangered). In Baden-Württemberg, however, it is not on the red list.
Systematics and nomenclature
The species is described by Fibiger et al. (2009) on the subgenus Triaena Hübner, 1818, together with arrow owl ( Acronicta psi ) and the alder arrow owl ( Acronicta cuspis ). No subspecies are listed. There are at least three synonyms.
swell
Individual evidence
- ↑ a b Red Lists
- ↑ a b c Fibiger (2009: p. 44/5)
- ↑ Ebert (1997: pp. 18-21)
- ↑ Walter Forster , Theodor A. Wohlfahrt : The butterflies of Central Europe. Volume 4: Owls. (Noctuidae). Franckh'sche Verlagshandlung, Stuttgart 1971, ISBN 3-440-03752-5 .
literature
- Günter Ebert (Ed.): The Butterflies of Baden-Württemberg Volume 5, Moths III (Sesiidae, Arctiidae, Noctuidae). Ulmer Verlag Stuttgart 1997. ISBN 3-800-13481-0
- 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
