Japanese oak silk moth

Japanese oak silk moth
	Japanese oak silk moth ( Antheraea yamamai ), ♂
Systematics
Class :	Insects (Insecta)
Order :	Butterflies (Lepidoptera)
Family :	Peacock moth (Saturniidae)
Subfamily :	Saturniinae
Genre :	Antheraea
Type :	Japanese oak silk moth
Scientific name
	Antheraea yamamai
	( Guérin-Méneville , 1861)

The Japanese oak silk moth ( Antheraea yamamai ) ( specific epithet from Japanese yamamayu ( 山繭 ) for "mountain silkworm cocoon") is a butterfly of the peacock moth family (Saturniidae). The species was originally only distributed in East Asia and was imported to Europe by humans for silk breeding. With a wingspan of around 140 millimeters, it is one of the largest butterflies found in Central Europe and is unmistakable here. The main food of the caterpillars is oak ( Quercus ).

features

butterfly

Japanese oak silk moth ♀

Antennae of the male

Eggs

Japanese oak silkworm caterpillar

detached cocoon

According to de Freina & Witt, the moths reach a wingspan of 110 to 140 millimeters in both sexes, Pittaway specifies a maximum wingspan of 152 millimeters. The males have a yellow-brown basic color and are strongly scalyed brown-red. On the forewings, the anterior medial line is dark brown and not very clearly developed. The post-median line, which is also colored, is stronger in comparison. The first line is wavy, the second is straight. An equally strong, white band borders the postmedian line on the outside. At an angle to the inner wing of the wing, below the median vein, an oblique transverse ligament delimits the base from the disk region . Above the median vein there is another transverse ligament in the disk area, which runs to the wing leading edge. This is broad and bulging gray-white. There is an ophthalmic spot in the middle of both the fore and hind wings . The eye spots are unevenly rounded. On the inside they are lilac-pink and white delimited and flattened there. On the outside they are bordered yellow and black-brown. The hind wings are colored the same as the forewings, but their eye-spots have an elongated black spot on the side facing the wing's front edge. The outer edge of all wings is indented strongly wavy between the veins. Their hem is bright yellow.

The antennae of the males are fourfold, the red-brown comb teeth are very long. Her head is red-brown, the collar is light gray-brown with numerous white hairs. The thorax and abdomen are light yellow ocher. In the females, the antennae have only short comb teeth. You can recognize them by their much stronger body and the less wavy wing edges. The basic color of the females is more yellow and their much larger eye spots have a transparent window in the middle. The Japanese oak silk moth is very variable in color. In addition to the typical coloration described above, the animals can also be colored yellow, brown-gray, chocolate-brown, bronze-colored, red-brown, khaki-colored to chrome-yellow. In the latter color variant, which is rarely observed in males, the animals also have a red and pale pink color on the eye spots.

In Europe, the species is only similar to the Chinese oak silk moth ( Antheraea pernyi ), which is naturalized in northeastern Spain and Mallorca . It differs from this by the black spot that borders on the eye-spots of the hind wings. In the males of the similar species, the forewings are also clearly curved sickle-shaped towards the tip.

egg

The dorsoventrally flattened eggs are slightly oval at 2.6 by 2.5 millimeters. They are off-white, but their color is largely covered by a brown adhesive when the eggs are laid.

Caterpillar

The stocky caterpillars are 80 to 90 millimeters long and only appear in one color variant. Initially, the five millimeter long caterpillars are greenish-yellow with five black vertical stripes. Their tubercles are yellow with black hair on the back and sides, the lateral tubercles are black. From the second caterpillar stage onwards, the caterpillars have an apple-green basic color. Their black longitudinal lines disappear, the lateral yellow tubercles turn blue at the top, the head and legs are brown, and a pale yellow longitudinal line is formed above the spiracles . In the next stages of the caterpillar, the coloration is essentially retained, the head becomes greenish, and from the fourth stage onwards metallic dots appear on the sides. In the fifth stage, the tubercles essentially disappear and are replaced by tufts of yellow hair.

Doll

The pupa becomes 35 to 45 millimeters long. It is mahogany brown and has a cylindrical shape tapering towards both ends.

distribution and habitat

The natural range of the species covers large parts of East Asia. The subspecies A. yamamai bergmani , A. yamamai titan and A. yamamai ussuriensis are distributed from the Far East of Russia via Korea to China, the nominate subspecies was originally only distributed in Japan, it was introduced in India and Sri Lanka . It was also imported to Europe for silk breeding. Johann Mach, father of Ernst Mach and teacher and farmer in Veliki Slatnik , near Novo mesto in Slovenia - according to another source in nearby Dolenje Mokro Polje, municipality of Šentjernej (German: St. Bartlmä), made the first attempts at breeding . In 1868 some moths escaped him from breeding. Although the silk production was discontinued, the moths were regularly found in the area a few years after they had escaped. Ten years later the first specimens were found in Ljubljana . Little by little, other parts of Europe were colonized, where the species now occurs locally in several countries, but not infrequently. It is now common in northeast Italy, the south and east of Austria, the Czech Republic, Hungary, Slovenia, Croatia, Bosnia and Serbia. After 2001 the European area expanded significantly and the species was observed for the first time in Romania and in eastern Bavaria near Passau . The species was also introduced by humans in India and Sri Lanka.

The animals inhabit deciduous forests and tree-rich habitats in the lowlands, in which many oaks ( Quercus ) grow.

Way of life

The nocturnal moths hatch mainly in the late afternoon or evening in late summer. To do this, they soften their cocoon at one end and loosen the threads. Most females lure the males with pheromones that same night . The pairing takes place just before midnight and takes about three hours. Then the males look for new partners. Both the male and the female are strongly attracted by light sources. The animals can often be found on or near street lights during the day.

Flight time

The moths fly in one generation in both Japan and Europe. In Japan, the flight time ranges from late July to October with a maximum in September. A very similar phenology was found in Austria, where the moths fly from the beginning of August to the beginning of October with a maximum around August 20.

Food of the caterpillars

The caterpillars mainly feed on the leaves of various species of oak ( Quercus ). They are also found on red beech ( Fagus sylvatica ), sweet chestnut ( Castanea sativa ), hornbeam ( Carpinus ), roses ( Rosa ) and hawthorns ( Crataegus ).

development

After mating, the females look for host plants. They then climb around on them and lay their eggs in orderly rows on the branches that can be reached quickly, as they are very sluggish due to the weight of their many eggs. Only after about 30 eggs have been laid are the remaining eggs laid on the plants in flight, as usual, and then laid in a larger area. Rows of up to eight are placed on the branches. The eggs hibernate there and the caterpillars do not hatch until April of the following year. After hatching, the caterpillar eats parts of the egg shell and then wanders off to find a suitable resting place in a tuft of leaves at some distance from the hatching site. This migration takes a few days. From the third stage onwards, many caterpillars become mobile and then change their feeding place about every four days. This could be related to the fact that in later stages they would eat a lot of leaves and then draw a lot of attention to themselves. Pupation takes place in a narrow, strong, oval, closed, yellow to light green cocoon , which has a loose, whitish covering. It is spun in a tuft of oak leaves on the food plants and is attached to the nearest branch.

Specialized enemies

The type that are Raupenfliege Exorista sorbillans , the parasitic wasp Pimpla instigator , and the wasp Trichogramma chilonis as parasitoids proven.

The golden oriole ( Oriolus oriolus ) hunts the moths while they rest hidden in the foliage. When attacked, the moths try to fly vertically into the sky or to drop to the ground. There they remain in the foliage for some time and are well camouflaged by their color.

Hazard and protection

The species occurs only locally in Europe, but not infrequently. Since it was introduced here by humans, it does not make sense to include it in the Red List of Endangered Species .

Systematics

According to the results of a molecular biological investigation of several species of the genus Antheraea , it is assumed that the Japanese oak silk moth is most closely related to the Chinese oak silk moth ( Antheraea pernyi ).

supporting documents

Individual evidence

^ Toshie M. Evans: A Dictionary of Japanese Loanwords . Greenwood, 1997, ISBN 0-313-28741-4 , pp. 215 ( limited preview in Google Book search).
↑ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j ^k ^l ^m ⁿ ^o ^p Saturniidae of Europe: Antheraea yamamai. AR Pittaway, accessed November 29, 2011 .
↑ ^a ^b ^c ^d 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. 398 .
↑ Saturniidae of Europe: Antheraea pernyi. AR Pittaway, accessed November 30, 2011 .
↑ Fritz Hoffmann: Remarkable finds of some lepidoptera species since the end of the Styrian fauna in 1929. (PDF; 1.0 MB) Journal of the Vienna Entomologists Association, year 27, 1942.
^ Y. Kato, M. Yamauchi, Y. Katsu and S. Sakate: Studies on summer Diapause in Pupae of Antheraea yamamai (Lepidoptera: Saturniidae): I. Shortening of the 'Pupal' Duration under Certain Environmental Conditions. Applied Entomology and Zoology 14 (4), 1979: pp. 389-396
^ Hermann Kühnert: The spread of Antheraea yamamai Guer. in the Deutschlandsberg district (Lepidoptera, Saturniidae). (PDF; 593 kB) Journal of the Vienna Entomological Society 54, 1969: pp. 134-138
↑ M. Dharma Prasad, Dmitry L. Nurminsky, Javaregowda Nagaraju: Characterization and molecular phylogenetic analysis of mariner elements from wild and domesticated species of silkmoths , Molecular Phylogenetics and Evolution 25 (2002), pp 210-217.

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 .