Tree of God spinner
| Tree of God spinner | ||||||||||||
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Tree of God Spinner ( Samia cynthia ), male |
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| Systematics | ||||||||||||
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| Samia cynthia | ||||||||||||
| ( Drury , 1773) |
The Samia Cynthia ( Samia cynthia ), also Ailanthus Spinner called, is a butterfly from the family of saturniidae (Saturniidae). In addition to the nominate subspecies, the subspecies Samia c. ricini and samia c. pryeri differentiated. The species, originally native to Asia, was introduced for the breeding of silkworms in large parts of the world. They are therefore found, for example, in climatically favorable southern Europe wherever the main food plant of the caterpillars, the tree of the gods ( Ailanthus altissima ), which also comes from Asia, was planted as an ornamental tree or has grown wild; mostly in cities. In India the dolls are eaten and in Nepal they are used as chicken feed.
features
butterfly
The moths have a wingspan of 100 to 120 millimeters (males) or 120 to 130 millimeters (females). The wings of the females are less stretched than those of the males and also less curved on the outer edge of the front wing. The antennae of the males are pale red-brown and four-fold short pinnate. In females they are relatively long and double-pinnate.
The species is unmistakable in Europe. It is similar to butterflies of the genera Callosamia from North America, Epiphora from Africa and Attacus from Southeast Asia. The body is relatively small with a length of less than 25 millimeters. The body of the female is plumper than that of the male. It has a clay yellow color, with the neck collar, the belly band and the tufts of wool and stripes on the abdomen being whitish-gray. The front wings are clay yellow to olive brown. At the base of the forewing, they have a white band that is strongly angled towards the body and has a black border on the outside. The band extends to the disk area and has two median teeth there, the upper part of which opens into the lower part of the elongated moon spot. This is transparent and thinly white bordered on its edge directed towards the wing leading edge. Behind it the stain is filled in with a broad clay yellow color. The moon spot separates a white discal band adjoining it on the outside into two parts curved slightly towards the body, which are bordered black on the inside and red-violet on the outside. The outer part of the wings is sprinkled with black scales . A fine submarginal band is formed, which is black above and gray-brown in the lower part of the forewing. It doesn't reach the wingtip. Close to the wing tip (postapical) is a large gray spot that is jagged white on the outside. This spot disappears diffusely inwards to the postapical area. A large, oval, black eye spot is located in the subapical area near this spot.
The hind wings are colored in the same way as the forewings, but have less inwardly curved discal ligament parts and a double, gray-green, fine submarginal ligament, of which the inner one is interrupted several times. On the underside, both pairs of wings look very similar to the top, but they lack the line on the basal half. The sexes do not differ in their coloration, but are variable. The forma advena has a receding gray postapical area and the forma parisiensis has a yellowish-brown basic color.
egg
The elongated eggs measure 1.5 by 1 millimeter. They have a grayish-white color and are attached to the food plants by the female with a brown secretion. The crescent-shaped clutches consist of up to 400 eggs.
Caterpillar
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The caterpillars are 65 to 80 millimeters long. They are about four millimeters long when they hatch and initially eat the egg shell. They are predominantly yellow in color and have conical tubercles with a black tip. The legs and head are black. Long rows of black dots run along the body. In the second stage, the basic color becomes paler. The head capsule has black stripes. In the third stage, the caterpillars can pull their front body into the body segments behind. The body is pale yellow, the tubercles on the back and sides are white. Black areas on the pusher stand out. From the fourth stage, the head becomes light brown, the yellowish green body is white, powder-like and the legs are shiny yellow. In the last stage the head is greenish and the powdered body is colored pale blue-green underneath. Some of the tubercles are bluish.
Doll
The pale brown doll is 27 to 30 millimeters long and cylindrical in shape, but becomes narrower towards the front and back.
Occurrence and habitat
The original range includes the cool, temperate to tropical zones of large parts of East and Southeast Asia and extends from the Russian Far East , Northeast China and Japan in the north to India , Malaysia , the Indochinese Peninsula , Java , the Andaman Islands and the Philippines in the south.
The species was widely used for the production of silk and is therefore to be found today in parts of Europe, North Africa, the Middle East and eastern North America. In southern Europe, the species is found sporadically in climatically favorable locations where trees of gods ( Ailanthus ) were planted as ornamental plants or have grown wild, such as in Paris , the Oise and Gironde departments , as well as in Alsace , in southern Switzerland , on the northern Italian lakes , such as Lake Garda , north-east Austria to Vienna , Hungary , Istria and central Slovenia. A population in northeast Spain near Barcelona has become extinct. Another isolated population is established in western Georgia .
The species inhabits open forests of the lowlands in its original range. In its new distribution areas, the species occurs mainly in cities and suburban areas. The species is rarely found here above 400 meters above sea level.
Way of life
The moths are active at night or occasionally at dusk. Most animals hatch in the late morning. The females use pheromones to attract the males in the evening of the same day or in the late afternoon . Mating occurs shortly after sunset and lasts up to 12 hours. During the day the animals rest between foliage.
Flight and caterpillar times
The moths fly in one generation in the north of their natural range and in up to three in the south. In the north of the European distribution area the animals fly in one generation in May and June, in southern Europe a second, partial generation occasionally occurs from September to October. Up to six generations per year can be achieved in breeding.
Food of the caterpillars
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In large parts of the natural range and also in Europe, the tree of the gods ( Ailanthus altissima ) is the most important food plant of the caterpillars. However, they are otherwise polyphagous and eat occasionally elderberry ( Sambucus ), walnut ( Juglans ), Prunus species, privet ( Ligustrum ), forsythia ( Forsythia ), castor bean ( Ricinus communis ), Laburnum ( Laburnum ), flour berries ( Sorbus ), lilac ( Syringa ), magnolias ( Magnolia ), laurels ( Laurus ) and other deciduous trees. In India, the main food plant of the subspecies S. cynthia ricini that occurs there is the wonder tree. Numerous other plant species are also eaten there, such as Heteropanax fragrans , Manihot utilissima , Evodia flaxinifolia and the tree of the gods. The caterpillars of the subspecies S. cynthia pryeri were found in South Korea on the tree of gods, but also on the Japanese aralia ( Aralia elata ) and Szechuan pepper ( Zanthoxylum piperitum ).
development
The females lay the eggs on the underside of the leaves of the food plants. The caterpillars hatch after 10 to 20 days. They quickly group themselves under the leaves, where they eat channels into them. Only from the third or fourth stage do they live individually. Pupation takes place in an elongated, pear-shaped, dirty brown, unlocked cocoon made of coarse silk, wrapped in a leaf that is attached to the nearest branch with silk. The cocoon remains there while the caterpillar overwinters. The cocoon is made of loose silk, inside with a firm web.
Specialized enemies
The type that are tracked flying Exorista larvarum , Exorista sorbillans , Pales pavida and Pales pumicata and the wasp Anastatus bifasciatus as parasitoids proven.
Hazard and protection
In northeast India, the wild stocks are now considered to be endangered by overexploitation and deforestation . Although the species only occurs locally in Europe, it is not uncommon. Since the tree of the gods spinner was introduced into Europe by humans, an inclusion in the red list of endangered species , as is the case in Spain, by de Freina et al. not considered useful.
Economical meaning
The tree of gods spinner was first introduced to Turin in Europe in 1856 to breed it for silk production. By 1861, breeding reached its peak with around 40 breeding farms in France and other locations in Northern Italy. In Austria, breeding was attempted in Atzgersdorf near Vienna. The silk obtained from the cocoons is very tough. Although the threads are combed, the silk fabric obtained from it is very coarse. The economic success was not achieved due to the poor quality of the silk and the breeding was quickly stopped again. The animals found in Europe today are descended from specimens that have escaped or been abandoned. It is the same with the tree of gods spinner in the United States . There, breeding was attempted around Philadelphia from the early 1860s , but was just as economically unprofitable and was discontinued.
In India the dolls are eaten and in Nepal they are used as chicken feed.
supporting documents
Individual evidence
- ↑ a b c d e f g h i j k l m n Saturniidae of Europe: Saturnia spini. AR Pittaway, accessed October 13, 2011 .
- ^ A b The Food Insects Newsletter, March 1993, Volume VI, No. 1. (No longer available online.) Gene R. DeFoliart, archived from the original on December 9, 2011 ; Retrieved January 8, 2012 . Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.
- ↑ a b c d e f g h i j Josef J. de Freina, Thomas J. Witt: Noctuoidea, Sphingoidea, Geometroidea, Bombycoidea . In: The Bombyces and Sphinges of the Western Palaearctic . 1st edition. tape 1 . EFW Edition Research & Science, Munich 1987, ISBN 3-926285-00-1 , p. 399 f .
- ↑ a b c d K. Vijayan, HJ Anuradha, CV Nair, AR Pradeep, AK Awasthi, B. Saratchandra, SAS Rahman, KC Singh, R. Chakraborti, SR Urs: Genetic diversity and differentiation among populations of the Indian eri silkworm, Samia cynthia ricini, revealed by ISSR markers. Journal of Insect Science 6:30, 2006 (online: [insectscience.org/6.30])
- ↑ Bo Youn Kim, Young Whan Choi, Nam Sook Park, Sang Mong Lee: Collection and Characteristics of the Wild Solkmoth, Samia cynthia pryeri in Korea. International Journal of Industrial Entomology, Vol 3, No. 1, 2001 p. 101ff. (online: pdf: [1] )
- ↑ a b P. Huemer, W. Rabitsch: 6.3.19 Butterflies (Lepidoptera). - 354-362. In: F. Essl, & W. Rbitsch: Neobiota in Austria. Federal Environment Agency, Vienna, 2002, p. 355f. (online: pdf: [2] ; PDF file; 4.1 MB)
- ^ Paul M. Tuskes, Michael M. Collins, James P. Tuttle: The Wild Silk Moths of North America: A Natural History of the Saturniidae of the United States and Canada. Cornell University Press, 1996.
literature
- Josef J. de Freina, Thomas J. Witt: Noctuoidea, Sphingoidea, Geometroidea, Bombycoidea . In: The Bombyces and Sphinges of the Western Palaearctic . 1st edition. tape 1 . EFW Edition Research & Science, Munich 1987, ISBN 3-926285-00-1 .
