Gamma owl
| Gamma owl | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Gamma owl ( Autographa gamma ) |
||||||||||||
| Systematics | ||||||||||||
|
||||||||||||
| Scientific name | ||||||||||||
| Autographa gamma | ||||||||||||
| ( Linnaeus , 1758) |
.jpg)
.jpg)
The Silver Y ( Autographa gamma ), also Pistoleneule called, is a butterfly ( moth ) from the family of cutworms (Noctuidae).
features
The gamma owl is a medium-sized butterfly with a wingspan of 35 to 40 millimeters. It is gray to brown in color and, like many species of the subfamily Plusiinae, has a characteristic drawing on the front wings, which is similar to the gamma from the Greek alphabet and from which the name is derived. While Macdunnoughia confusa ( yarrow-silver owl ) can be easily and clearly distinguished from Autographa gamma , a reliable differentiation from Autographa pulchrina , Autographa buraetica , Autographa mandarina , Autographa jota , Autographa macrogamma as well as Trichoplusia ni , Ctenoplusia limbirena and cornutiplus can only be experienced by specialists be performed. In the German-speaking region of Central Europe, however, the moths that are observed in cities, in gardens and on balcony flowers mainly belong to Autographa gamma .
The caterpillars reach a length of up to 25 millimeters and are variable in color. The spectrum ranges from yellowish green to bluish green to a dark greenish gray. The caterpillars only have three pairs of belly legs. The back has a pattern of fine white lines and rings. The stigma band is white or yellowish. The head is green and has characteristic black side stripes, which can sometimes be missing.
The pupa is black-brown, the trunk-sheath elongated into a bulbous shape. There are some bristles on the button-shaped cremaster .
Similar species
- Ziest's silver owl Autographa pulchrina (Haworth, 1809)
- Buryat silver owl Autographa buraetica (Staudinger, 1892)
- Mandarin silver owl Autographa mandarina (Freyer, 1846)
- Iota silver owl Autographa jota (Linnaeus, 1758)
- Macrogamma silver owl Autographa macrogamma (Eversmann, 1842)
- Ash gray mute owl Trichoplusia ni (Hübner, 1803)
- Limbirena silver owl Ctenoplusia limbirena (Guenée, 1852)
- Cornutiplusia circumflexa (Linnaeus, 1767)
Flight time
The gamma owl forms two or more generations per year, which usually overlap and can rarely be separated safely. Depending on the weather, moths can appear from late February to early December; in Central Europe the main flight time is between May and October.
Geographical distribution and habitat
The gamma owl is a classic migratory butterfly that is widespread in Germany. Due to its day and night activity, it is one of the most well-known species of moth. The strongly varying population sizes in Germany are largely dependent on the quantity of people arriving from the south. According to Ebert, the down-to-earth nature of the species in Baden-Württemberg has not yet been clearly clarified. It is also unclear to what extent the overwintering caterpillars contribute to the overall population. The total distribution extends over North Africa and Eurasia (with the exception of the tropical area), whereby the species also reaches the subarctic parts of Asia, Scandinavia , Iceland and Greenland as immigrants .
The moth does not specialize in particular habitats and can occur anywhere. Only closed forest areas are avoided or flown over.
Way of life
The females prefer to lay their eggs in gaps with open ground around them. From this it follows u. a. a preference for plants grown in the garden and field. The eggs are laid individually or in small groups from May to August.
The caterpillars hatch after about two weeks and eat polyphagous . The caterpillar forage plants include a large number of plants without particular preference such as nettle ( Urtica spec.), Dandelion ( Taraxacum spec.), Lettuce ( Lactuca sativa ), etc. A total of 40 species from 20 families are known for Baden-Württemberg alone , with these List includes a particularly large number of cultivated plants.
The young caterpillars live hidden on the food plants and rest on the underside of the leaves. Later they are mainly nocturnal and hide during the day on the ground or on parts of plants close to the ground. To pupate, the caterpillars lay a light, relatively transparent web between parts of the plant. Often the leaf margins are drawn together starting from the midrib and a web is created in them. The cocoon is not necessarily placed on a food plant, but the caterpillars cover a few meters in search of a suitable pupation site.
The butterfly is also a generalist when it comes to food. The list of nectar plants ranges from monocot plants such as Juncus effusus , Colchicum autumnale , Iris germanica hybrids to trees , e.g. B. the winter linden ( Tilia cordata ), and a variety of shrubs to herbaceous plants of the Rosopsida . When searching for nectar, the animals fly in rapid whirring flight from flower to flower. They often do not sit down quietly, but stand in front of the flower with fluttering wings. They hold on to the flower with their front legs. The gamma owl flies both day and night.
The predators include starlings and crows , which systematically clear heavily infested areas of the owl caterpillar and pupae. Bats, like the long-eared gray , also prey on the moths of the gamma owl .
Occasionally there are mass reproductions, most recently in southwest Germany in 1991, 1987, 1982 and 1975. This causes considerable damage to cultivated plants.
When flying at night, gamma-ray columns are based on the moonlight. Like many other moths, they are attracted by artificial light sources , including floodlights in sports stadiums. In addition to nectar, they also absorb human sweat , which at the 2016 European Football Championship final led to the Stade de France swarming with gammae and one of them settling in front of the cameras in the sweaty face of the injured Portuguese striker Cristiano Ronaldo .
swell
Individual evidence
- ↑ David J. Carter, Brian Hargreaves: Caterpillars and Butterflies of Europe and their Forage Plants. Blackwell Wissenschaftsverlag 1987, ISBN 3-8263-8139-4
- ↑ 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. 268.
- ↑ a b Günter Ebert, Axel Steiner: The Butterflies of Baden-Württemberg Volume 6, Nachtfalter IV. Ulmer Verlag Stuttgart 1997 (Eulen (Noctuidae) 2nd part), ISBN 3-8001-3482-9
- ↑ Wolfram Mey (entomologist at the Natural History Museum Berlin) in Lars Wallrodt: That's why Cristiano Ronaldo got the moths . Die Welt , July 11, 2016.
Web links
- www.lepiforum.de
- www.schmetterling-raupe.de
- www.insektenbox.de
- Moths and Butterflies of Europe and North Africa (English)
- Autographa gamma in Fauna Europaea