| Domesticated Silkmoth Silkworm | ||||||||||||||
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 Paired male (above) and female (below)  Silkworm, 4th or 5th instar | ||||||||||||||
| Conservation status | ||||||||||||||
Domesticated | ||||||||||||||
| Scientific classification | ||||||||||||||
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| Binomial name | ||||||||||||||
| Bombyx mori Linnaeus, 1758 | ||||||||||||||
| Synonyms | ||||||||||||||
Bombyx mori mori |
The silkworm is the larva or caterpillar of Bombyx mori (Latin: "silkworm of the mulberry tree"), the domesticated silkmoth. Carl Linnaeus (Latinized as Carolus Linnaeus, also known after his ennoblement as, May 23 new style (13 May old style 1707 who laid the foundations for The book Systema Naturae was one of the major works of the Swedish doctor of medicine Carolus Linnaeus. In Scientific nomenclature, synonyms are different Scientific names used for a single Taxon. A larva ( Latin; plural larvae) is a juvenile form of Animal with indirect development, undergoing Metamorphosis (for example Caterpillars are the Larval form of a member of the order Lepidoptera (the Insect order comprising butterflies and Moths Latin ( lingua Latīna, laˈtiːna is an Italic language, historically spoken in Latium and Ancient Rome. A moth in the family Bombycidae, it is very important economically as the producer of silk. A moth is an Insect closely related to the Butterfly, both being of the order Lepidoptera. Bombycidae is a family of Moths The best-known species is Bombyx mori ( Linnaeus) or silkworm native to northern China and domesticated Silk is a natural Protein Fiber, some forms of which can be woven into Textiles The best-known type of silk is obtained from cocoons It is entirely dependent on humans for its reproduction and no longer occurs naturally in the wild. Silk culture has been practiced for at least 5,000 years in China (Goldsmith et al. 2004). A silkworm's preferred food is White Mulberry leaves. The White Mulberry ( Morus alba) is a short-lived fast-growing small to medium sized Mulberry tree which grows to 10–20 m tall It is native to northern China. China ( Wade-Giles ( Mandarin) Chung¹kuo² is a cultural region, an ancient Civilization, and depending on perspective a National
Its nearest wild relative is Bombyx mandarina which is able to hybridize with the domestic taxon (Goldsmith et al. Bombyx mandarina, the Wild Silkmoth, is an insect from the Moth family Bombycidae. A taxon (plural taxa) or taxonomic unit, is a name designating an organism or a group of Organisms In Biological nomenclature according to 2004), and which ranges from northern India to northern China, Korea and Japan. It is not known when the domestic silkmoth diverged from its wild relatives, only that the domestic population originated from inland Chinese rather than Japanese or Korean stock (Maekawa et al. 1988, Arunkumar et al. 2006). Molecular clock studies suggesting an age of many millions of years cannot be taken seriously, as they assume that both species have evolved with constant speed since their divergence. The molecular clock (based on the molecular clock hypothesis ( MCH) is a technique in Molecular evolution to relate the divergence time of two Species eVolution is the third Album by eLDee, it was due to be released in 2008
This is not correct however due to the domestication process having accelerated the pace of evolution (a similar problem affects the attempt to resolve the phylogeny of domestic Western honey bee subspecies). In fact, the domestic silkworm has undergone such strong artificial selection that it is completely unable to survive in the wild for any length of time. Artificial selection is the intentional breeding for certain traits or combinations of traits over others and is synonymous with " Selective breeding " It is probably the most heavily domesticated animal known apart from domestic hybrids such as mules. Domestication (from Latin domesticus) refers to the process whereby a Population of Animals In Biology, hybrid has two meanings The first meaning is the result of interbreeding between two animals or plants of different taxa. In its common modern meaning a mule is the offspring of a male Donkey and a female Horse, which is classified as a kind of F1 hybrid. Regardless whether the domestic silkworm is derived from a wild species that has since gone extinct, or from a stock of Bombyx mandarina that was taken into human care some 4,600 years ago (Yoshitake 1968), breeding of silkworms cannot have originated before the Neolithic as the tools necessary to make use of the silk thread on a large scale only have become available since then. In Biology and Ecology, extinction is the cessation of existence of a Species or group of taxa. The Neolithic (from Greek νεολιθικός — neolithikos from νέος neos, "new" + λίθος lithos
Sometimes, the Wild Silkmoth is considered a subspecies of Bombyx mori (the older specific name is used as per ICZN rules) as they are theoretically capable of full hybridization. In Zoology, as in other branches of Biology, subspecies is the Taxonomic rank immediately subordinate to a Species. In zoological nomenclature a specific name or specific epithet is the second part (second name in the name of a Species (a Binomen) "ICZN" redirects here It is also sometimes used for the International Code of Zoological Nomenclature in error However, due to the domesticated moth's requirement for human care to survive, gene flow is all but nonexistent and thus, despite its apparently recent origin, the domestic animal is generally treated as a distinct monotypic species today. In Population genetics, gene flow (also known as gene migration) is the transfer of Alleles of Genes from one Population to another Monotypic is an adjective that refers to a taxonomic group with only one type: In Botany, "monotypic" means that a Taxon has only
Contents |
Development
Eggs take about ten days to hatch. Silkworms have a strong appetite, as do all lepidopteran larvae. Lepidoptera is an order of Insect that includes Moths and butterflies. They eat day and night, preferring White Mulberry but not being strictly monophagous they also take other species of Morus and some other Moraceae. The White Mulberry ( Morus alba) is a short-lived fast-growing small to medium sized Mulberry tree which grows to 10–20 m tall Moraceae is a family of Flowering plants commonly known as the mulberry or fig family Hatchlings and second-instar larvae are called kego (毛蚕, "hairy silkworm") in Japan, or chawki in India. For a topic outline on this subject see List of basic Japan topics. India, officially the Republic of India (भारत गणराज्य inc-Latn Bhārat Gaṇarājya; see also other Indian languages) is a country They are covered with little black hairs. When the color of their heads turns darker, it means that it is time for them to molt. Ecdysis is the Molting of the Cuticula in Arthropods and related groups ( Ecdysozoa) Later instars are white, nude, and have a horn on the back.
After they have molted four times (i. e. , in the fifth instar), their bodies turn slightly yellow and their skin becomes tighter. The larvae enclose themselves in a cocoon of raw silk produced in the salivary glands that provides protection during the vulnerable, almost motionless pupal state. A pupa ( Latin pupa for doll pl pupae or pupas) is the life stage of some Insects undergoing transformation The salivary glands in mammals are exocrine glands that produce saliva Many other Lepidoptera produce cocoons, but only a few large Bombycidae and Saturniidae have been exploited for fabric production. Lepidoptera is an order of Insect that includes Moths and butterflies. Bombycidae is a family of Moths The best-known species is Bombyx mori ( Linnaeus) or silkworm native to northern China and domesticated The Saturniidae, collectively known as saturniids, are among the largest and mostspectacular of the Lepidoptera, with an estimated 1300 to 1500 different described
The cocoon is made of a single continuous thread of raw silk from 300 to 900 meters (1000 to 3000 feet) long. Silk is a natural Protein Fiber, some forms of which can be woven into Textiles The best-known type of silk is obtained from cocoons The fibers are very fine and lustrous, about 10 micrometers (1/2500th of an inch) in diameter. A micrometre ( American spelling: micrometer; symbol µm) is one millionth of a Metre, or equivalently one thousandth of a Millimetre About 2,000 to 3,000 cocoons are required to make a pound of silk. Based on 1 kilometer (about 1100 yards) per cocoon, ten unraveled cocoons could theoretically extend vertically to the height of Mt Everest. Mount Everest, also called Sagarmatha (सगरमाथा meaning Head of the Sky) or Chomolungma, Qomolangma or Zhumulangma (in At least 70 million pounds of raw silk are produced each year, requiring nearly 10 billion pounds of mulberry leaves. According to E. L. Palmer (Fieldbook of Natural History 1949), one pound of silk represents about 1,000 miles of filament. The annual world production represents 70 billion miles of silk filament, a distance well over 300 round trips to the sun.
If the animal is allowed to survive after spinning its cocoon, it will release proteolytic enzymes to make a hole in the cocoon so that it can emerge as a moth. Proteolysis is the directed degradation ( digestion) of Proteins by cellular Enzymes called Proteases or by intramolecular digestion Enzymes are Biomolecules that catalyze ( ie increase the rates of Chemical reactions Almost all enzymes are Proteins This would cut short the threads and ruin the silk. This article is about the fiber product For the type of joke see Shaggy dog story. Instead, silkworm cocoons are boiled. The heat kills the silkworms and the water makes the cocoons easier to unravel. Often, the silkworm itself is eaten (see also below).
The adult phase (the moth) cannot fly. The silkmoths have a wingspan of 3-5 cm (1. 5 - 2 inches) and a white hairy body. Females have about twice to three times the bulk of males (for they are carrying many eggs), but are similarly colored. Adults in the Bombycidae have reduced mouth parts and do not feed.
 Females laying eggs |  7-day (second instar) kego |  Male adult. Scale is 15 mm |  Female adult. Scale is 20 mm |
Scientific and medical uses
Due to its large size and ease of culture, the silkworm has long been a model organism in the study of Lepidopteran and arthropod biology (Goldsmith et al. A model organism is a Species that is extensively studied to understand particular biological Phenomena, with the expectation that discoveries made 2004). Fundamental findings on pheromones, hormones, brain structures and physiology were made with the silkworm (Grimaldi & Engel 2005). A pheromone (from Greek φέρω phero "to bear" + ‘ορμόνη " Hormone " is a Chemical that triggers a natural Hormones (from Greek ὁρμή - "impetus" are chemicals released by cells that affect cells in other parts of the body To characterize the first known pheromone, bombykol, extracts were needed from 500,000 individuals because only very small quantities are produced (Scoble 1995). Bombykol is a Pheromone released by the female Silkworm moth to attract mates
Currently, research is focusing on genetics of silkworms and genetic engineering. Many hundreds of strains are maintained, and over 400 Mendelian mutations have been described (Goldsmith et al. Mendelian inheritance (or Mendelian genetics or Mendelism) is a set of primary tenets relating to the transmission of hereditary characteristics from parent 2004). One useful mutant for the silk industry confers the ability to feed on food besides mulberry leaves, including an artificial diet (Goldsmith et al. 2004). The genome has been sequenced (Mita et al. 2004), and many projects have worked on genetic engineering of silkworms to produce desirable proteins in the place of silk. Such proteins include human drugs (Grimaldi & Engel 2005).
Silkworm is the source of the traditional Chinese medicine jiāngcán ("stiff silkworm", simplified Chinese: 僵蚕; traditional Chinese: 僵蠶, trade name "Bombyx batryticatus"). Traditional Chinese medicine (also known as TCM,) includes a range of traditional medical practices originating in China. It is the dried body of the 4-5th instar larva which has died of the white muscardine disease. A larva ( Latin; plural larvae) is a juvenile form of Animal with indirect development, undergoing Metamorphosis (for example Beauveria bassiana is a Fungus that grows naturally in soils throughout the world and acts as a Parasite on various Insect species causing Its uses are to dispel flatulence, dissolve phlegm and relieve spasms. Flatulence is the production of a mixture of gases in the digestive tract of Mammals that are byproducts of the digestion process Phlegm ( is sticky Fluid secreted by the Mucous membranes of Humans and other Animals. A spasm is a sudden involuntary contraction of a Muscle, a group of muscles or a hollow organ, or a similarly sudden Contraction of an Orifice
Cuisine
Like many insect species, silkworm pupae are eaten in some cultures (see Entomophagy). Entomophagy (from Greek ἔντομος éntomos, "insect(ed" and φᾰγεῖν phăgein, "to eat" which together In Korea they are boiled and seasoned to make a popular snack food known as beondegi. Korea is a geographic area composed of two sovereign countries a civilization and a former state situated on the Korean Peninsula in East Asia. Beondegi are a popular snack food in Korean cuisine. Literally meaning " chrysalis " or " Pupa " in Korean Beondegi are steamed or boiled In China street vendors sell roasted silkworm pupae. China ( Wade-Giles ( Mandarin) Chung¹kuo² is a cultural region, an ancient Civilization, and depending on perspective a National Some say they taste like chicken.
Silkworm legends
In China, there is a legend that the discovery of the silkworm's silk was by an ancient empress called Xi Ling-Shi (Chinese: 嫘祖; pinyin: Léi Zǔ). Leizu ( was a legendary Chinese empress&mdashwife of the Yellow Emperor. Pinyin, more formally Hanyu pinyin, is the most common Standard Mandarin Romanization system in use She was drinking tea under a tree when a cocoon fell into her tea. She picked it out and as it started to wrap around her finger, she slowly felt a warm sensation. When the silk ran out, she saw a small cocoon. In an instant, she realized that this cocoon was the source of the silk. She taught this to the people and it became widespread. There are many more legends about the silkworm.
The Chinese guarded their knowledge of silk. It is said that a Chinese monk smuggled silkworms, in a hollow stick, out of China and sold the secret to Europe, which was against the law and the punishment would be execution in the town square.
See also
- Ginkgo, another Chinese species not known to exist in an entirely wild state
- History of Silk
- Silk Road
References
- Arunkumar, K. Ginkgo ( Ginkgo biloba; in Chinese 銀杏 Pinyin romanization yín xìng) frequently misspelled as "Gingko" and also known According to Chinese tradition the history of silk begins in the 27th century BCE The Silk Road, or Silk Routes, are an extensive interconnected network of Trade routes across the Asian continent connecting East South and Western Asia with the P. ; Metta, Muralidhar & Nagaraju, J. (2006): Molecular phylogeny of silk moths 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 (HTML abstract). A digital object identifier ( DOI) is a permanent identifier given to an Electronic document. Supplementary figure 1 (JPG) Supplementary figure 2 (JPG) Supplementary figure 3 (JPG)
- Goldsmith, Marian R. ; Shimada, Toru & Abe, Hiroaki (2004): The genetics and genomics of the silkworm, Bombyx mori. Annu. Rev. Entomol. 50: 71-100. This is the article on the publisher Annual Reviews whose titles are invariably called Annual review of. PMID 15355234. doi:10.1146/annurev.ento.50.071803.130456 (HTML abstract)
- Grimaldi & Engel (2005): Evolution of the Insects. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document. Cambridge University Press.
- Maekawa, H. ; Takada, N. ; Mikitani, K. ; Ogura, T. ; Miyajima, N. ; Fujiwara, H. ; Kobayashi, M. & Ninaki, O. (1988): Nucleolus organizers in the wild silkworm Bombyx mandarina and the domesticated silkworm B. mori. Chromosoma 96: 263–269. doi:10.1007/BF00286912 (HTML abstract)
- Mita, Kazuei; Kasahara, Masahiro; Sasaki, Shin; Nagayasu, Yukinobu; Yamada, Tomoyuki; Kanamori, Hiroyuki; Namiki, Nobukazu; Kitagawa, Masanari; Yamashita, Hidetoshi; Yasukochi, Yuji; Kadono-Okuda, Keiko; Yamamoto, Kimiko; Ajimura, Masahiro; Ravikumar, Gopalapillai; Shimomura, Michihiko; Nagamura, Yoshiaki; Shin-i, Tadasu; Abe, Hiroaki; Shimada, Toru; Morishita, Shinichi & Sasaki, Takuji (2004): The Genome Sequence of Silkworm, Bombyx mori. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document. DNA Research 11(1): 27-35. PMID 15141943. doi:10.1093/dnares/11.1.27 PDF fulltext
- Scoble, M. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document. J. (1995): The Lepidoptera: Form, function and diversity. Princeton University Press.
- Yoshitake, N. (1968): Phylogenetic aspects on the origin of Japanese race of the silkworm, Bombyx mori L. . Journal of Sericological Sciences of Japan 37: 83–87.
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