Bombyx mandarina

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Wild silk moth
Bombyx mandarina formosana (35848743764).jpg
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Lepidoptera
Family: Bombycidae
Genus: Bombyx
Species:
B. mandarina
Binomial name
Bombyx mandarina
(Moore, 1872)
Synonyms
  • Bombyx mori mandarina(Moore, 1872)
  • Theophila mandarinaMoore, 1872

Bombyx mandarina, the wild silk moth, is a species of moth in the family Bombycidae. It is the closest relative of Bombyx mori , the domesticated silk moth. The silkworm is the larva or caterpillar of a silk moth. Unlike the domesticated relative which is unable to fly or indeed persist outside human care, the wild silk moth is a fairly ordinary lepidopteran. Its main difference from the domesticated taxon is the more slender body with well-developed wings in males, and the dull greyish-brown colour.

Contents

Phylogeny and systematics

Bombyx mandarina and the domesticated Bombyx mori constitute two of the currently identified eight species of the genus Bombyx, the true or mulberry silk moths. The origin of the domestic silk moth is enigmatic. It has been suggested that it is the survivor of an extinct species that diverged from the ancestors of Bombyx mandarina millions of years ago. However, this is based on an untenable molecular clock hypothesis that assumes that wild and domestic silk moths evolved equally fast after their lineages diverged. Rather, the effects of artificial selection have accelerated evolution in the domestic form to a point where it is hard to trace the origin of the numerous breeds of domestic silk moths even with the most modern molecular phylogeny methods. [1] Conceivably, today's domestic silk moths are all descended from an initial stock of B. mandarina collected as far back as 5,000 years ago. [1] While wild silk could have been collected and used as threads, etc., since much earlier, the technology to breed and use silkworms from a domesticated stock did not exist before the late Neolithic.

However, it has been possible to trace the geographical origin of the domestic silk moth. The wild species occurs over a considerable range from inland China to Korea and Japan, and shows much (albeit subtle) variation; Chinese specimens have 56 chromosomes and Japanese specimens have 54. The populations from the northeastern end of the range, for example, differ in karyotype from those of inland China. Domestic silk moths are closer to the latter regarding mtDNA sequence data, and especially lack some genetic apomorphies of the northeastern B. mandarina. Thus, the initial domestic stock came from inland China. [2] [3]

B. mandarina is able to hybridize with B. mori. Both in the wild and a domesticated environment, females release pheromones and wait for males to be attracted and fly to them. However, B. mori males cannot fly. Hybridisation in the wild, therefore, inevitably means breeding between wild (B. mandarina) males and domestic (B. mori) females. Hybridization is possible in both directions in a domesticated environment.

Consequently, the two silk moths have been united as subspecies of a single species; in this case, the name Bombyx mori, which was published first, applies to both. However, today it is usually recognized that the domestic silk moth is entirely dependent on human care for its survival and thus has a level of reproductive isolation from its wild relatives.

Related Research Articles

<span class="mw-page-title-main">Silk</span> Fine, lustrous, natural fiber produced by various arthropods

Silk is a natural protein fiber, some forms of which can be woven into textiles. The protein fiber of silk is composed mainly of fibroin and is produced by certain insect larvae to form cocoons. The best-known silk is obtained from the cocoons of the larvae of the mulberry silkworm Bombyx mori reared in captivity (sericulture). The shimmering appearance of silk is due to the triangular prism-like structure of the silk fibre, which allows silk cloth to refract incoming light at different angles, thus producing different colors.

<i>Bombyx mori</i> Moth mainly used in the production of silk

Bombyx mori, commonly known as the domestic silk moth, is a moth species belonging to the family Bombycidae. It is the closest relative of Bombyx mandarina, the wild silk moth. Silkworms are the larvae of silk moths. The silkworm is of particular economic value, being a primary producer of silk. The silkworm's preferred food are the leaves of white mulberry, though they may eat other species of mulberry, and even leaves of other plants like the osage orange. Domestic silk moths are entirely dependent on humans for reproduction, as a result of millennia of selective breeding. Wild silk moths, which are other species of Bombyx, are not as commercially viable in the production of silk.

<i>Morus</i> (plant) Genus of plants

Morus, a genus of flowering plants in the family Moraceae, consists of 19 species of deciduous trees commonly known as mulberries, growing wild and under cultivation in many temperate world regions. Generally, the genus has 64 subordinate taxa, three of which are well-known and are ostensibly named for the fruit color of the best-known cultivar: white, red, and black mulberry, with numerous cultivars and some taxa currently unchecked and awaiting taxonomic scrutiny. M. alba is native to South Asia, but is widely distributed across Europe, Southern Africa, South America, and North America. M. alba is also the species most preferred by the silkworm, and is regarded as an invasive species in Brazil and the United States.

Sericulture, or silk farming, is the cultivation of silkworms to produce silk. Although there are several commercial species of silkworms, the caterpillar of the domestic silkmoth is the most widely used and intensively studied silkworm. This species of silkmoth is no longer found in the wild as they have been modified through selective breeding, rendering most flightless and without defense against predators. Silk is believed to have first been produced in China as early as the Neolithic period. Sericulture has become an important cottage industry in countries such as Brazil, China, France, India, Italy, Japan, Korea, Russia, and Thailand. Today, China and India are the two main producers, with more than 60% of the world's annual production.

<span class="mw-page-title-main">Bombykol</span> Sex pheromone of silk moths

Bombykol is a pheromone released by the female silkworm moth to attract mates. It is also the sex pheromone in the wild silk moth. Discovered by Adolf Butenandt in 1959, it was the first pheromone to be characterized chemically.

<i>Bombyx</i> Genus of moths

Bombyx is the genus of true silk moths or mulberry silk moths of the family Bombycidae, also known as silkworms, which are the larvae or caterpillars of silk moths. The genus was erected as a subgenus by Carl Linnaeus in his 10th edition of Systema Naturae (1758).

<i>Samia cynthia</i> Species of moth

Samia cynthia, the ailanthus silkmoth, is a saturniid moth, used to produce silk fabric but not as domesticated as the silkworm, Bombyx mori. The moth has very large wings of 113–125 mm (4.4–4.9 in), with a quarter-moon shaped spot on both the upper and lower wings, whitish and yellow stripes and brown background. There are eyespots on the outer forewings. The species was first described by Dru Drury in 1773.

<span class="mw-page-title-main">Bombycidae</span> Family of moths

The Bombycidae are a family of moths known as silkworm moths. The best-known species is Bombyx mori (Linnaeus), or domestic silk moth, native to northern China and domesticated for millennia. Another well-known species is Bombyx mandarina, also native to Asia.

<span class="mw-page-title-main">Thai silk</span> Silk from the cocoons of Thai silkworms

Thai silk is produced from the cocoons of Thai silkworms. Thailand's silkworm farmers cultivate both types of the domesticated silkworms that produce commercial silk: Samia ricini, commonly known as the eri silkworm, which produces matte eri silk, and the Bombyx mori, producer of the better known, glossy mulberry silk. The latter is by far the larger silk producer of the two.

<span class="mw-page-title-main">Silk industry in China</span>

China is the world's largest and earliest silk producer. The vast majority of Chinese silk originates from the mulberry silkworms. During the larval stage of its life cycle, the insects feed on the leaves of mulberry trees. Non-mulberry silkworm cocoon production in China primarily focuses on wild silk from the Chinese Tussah moth. This moth typically feeds on trees and its larvae spin coarser, flatter, yellower filament than the mulberry silkworms.

<span class="mw-page-title-main">Wild silk</span> A silk fibre from Asian moth silkworms

Wild silks have been known and used in many countries from early times, although the scale of production is far smaller than that from cultivated silkworms. Silk cocoons and nests often resemble paper or cloth, and their use has arisen independently in many societies.

<span class="mw-page-title-main">Eri silk</span> Silk from the cocoons of Samia ricini silkworms

Eri silk is the product of the domesticated silkworm Samia ricini, found mainly in North East India and some part of China and Japan. It was imported to Thailand in 1974. The name "eri" is derived from the Assamese word "era", which means "castor", as the silkworm feeds on castor plants. Eri silk is also known as endi or errandi in India. The woolly white silk is often referred to as the fabric of peace when it is processed without killing the silkworm. This process results in a silk called Ahimsa silk. Moths leave the cocoon and then the cocoons are harvested to be spun. The eri silkworm is the only completely domesticated silkworm other than Bombyx mori.

<i>Cricula trifenestrata</i> Species of moth

Cricula trifenestrata, the cricula silkmoth, is a species of wild silk moth of the family Saturniidae. It is found from India to the Philippines, Sulawesi, Java, and Sri Lanka.

<i>Antheraea pernyi</i> Species of moth

Antheraea pernyi, the Chinese oak tussar moth, Chinese tasar moth, or temperate tussar moth, is a large moth in the family Saturniidae. The species was first described by Félix Édouard Guérin-Méneville in 1855. Antheraea roylei is an extremely close relative, and the present species might actually have evolved from ancestral A. roylei by chromosome rearrangement.

The Bombyx hybrid is a hybrid between a male Bombyx mandarina moth and a female Bombyx mori moth. They produce larvae called silkworms, like all species of Bombyx. The larvae look a lot like the other variations. They are brown in the first half and gray at the bottom half, but they get larger black spots than other variations. Generally, they look like a normal Bombyx moth, but a bit darker. Hybrids are not used for silk, but for research. Because Bombyx mori males lost their ability to fly, their females are much more likely to mate with a male Bombyx mandarina. The reverse is possible, but both species have to be kept in the same container. Since Bombyx hybrids are much more common than the other variation, more is known about them.

<i>Bombyx huttoni</i> Species of moth

Bombyx huttoni, or the chocolate-tipped silk moth, is a moth belonging to the silk moth family, Bombycidae. It is closely related to the domestic silk moth.

<i>Antheraea paphia</i> Species of moth

Antheraea paphia, known as the South India small tussore, the tasar silkworm and vanya silkworm is a species of moth of the family Saturniidae found in India and Sri Lanka. The bulk of the literature on this species uses a junior synonym, Antheraea mylitta, rather than the correct name, A. paphia. It is one of a number of tasar silkworms, species that produce Tussar silk, a kind of wild silk that is made from the products of saturniid silkworms instead of the domesticated silkworm.

<span class="mw-page-title-main">Commercial butterfly breeding</span>

Commercial butterfly breeding or captive butterfly breeding is the practice of breeding butterflies and moths in controlled environments to supply the stock to research facilities, universities, zoos, insectariums, elementary and secondary schools, butterfly exhibits, conservation organizations, nature centers, individuals, and other commercial facilities. Some butterfly and moth breeders limit their market to wholesale customers while other breeders supply smaller volumes of stock as a retail activity. Some small scale and larger scale breeders limit their businesses to the provision of butterflies or moths for schools. Others provide butterflies to be used and released in commemorative events. The release usually occurs in the natural range of the butterfly.

<span class="mw-page-title-main">Ahimsa silk</span> Type of silk obtained without killing and harming silk worms

Ahimsa silk is a method of nonviolent silk breeding and harvesting. Wild silk moths are bred rather than the domestic variety. It allows the completion of the metamorphosis of the silkworm to its moth stage, whereas most silk harvesting requires the silkworms to be killed in their cocoon stage. No animals suffer or die for the silk to be produced, making it a favorable alternative to normal silk for those who object to harming animals.

Antheraea roylei is a large moth in the family Saturniidae occurring in Nepal, Thailand, Burma, Vietnam, West Malaysia, and the Himalayan regions of India. The species is considered to be the wild progenitor of the domesticated species known as Antheraea pernyi; the theory is that pernyi may have evolved from ancestral A. roylei by chromosome rearrangement during domestication.

References

  1. 1 2 Yoshitake, Narumi (1968). "Phylogenetic aspects on the origin of Japanese race of the silkworm, Bombyx mori L." The Journal of Sericultural Science of Japan (in Japanese). 37 (2): 83–87. doi: 10.11416/kontyushigen1930.37.83 .
  2. Yukuhiro, Kenji; Sezutsu, Hideki; Itoh, Masanobu; Shimizu, Koichi; Banno, Yutaka (2002). "Significant levels of sequence divergence and gene rearrangements have occurred between the mitochondrial genomes of the wild mulberry silkmoth, Bombyx mandarina, and its close relative, the domesticated silkmoth, Bombyx mori". Molecular Biology and Evolution. 19 (8): 1385–1389. doi: 10.1093/oxfordjournals.molbev.a004200 . PMID   12140251.
  3. Arunkumar, K.P.; Metta, Muralidhar; Nagaraju, J. (2006). "Molecular phylogeny of silkmoths reveals the origin of domesticated silkmoth, Bombyx mori from Chinese Bombyx mandarina and paternal inheritance of Antheraea proylei mitochondrial DNA". Molecular Phylogenetics and Evolution. 40 (2): 419–427. doi:10.1016/j.ympev.2006.02.023. PMID   16644243.