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Bangladesh Sericulture Development Board

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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.

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22-633: The Bangladesh Sericulture Development Board is a regulatory board in Bangladesh that is in charge of sericulture and is based in Rajshahi , Bangladesh . The Bangladesh Sericulture Development Board was formed in 1978 through the Presidential Ordinance 1977. It is responsible for the welfare sericulture workers and the promotion of the silk industry. The board owns Mulberry plantations for silk agriculture in Bangladesh. The board

44-461: A base for painting from the 16th century. Caterpillar nests were used to make containers and fabric in the Aztec Empire . To make a woven fabric, silk threads must first be either carded and spun , or extracted as a single intact thread. Commercially reared silkworms of the species Bombyx mori (Linnaeus, 1758) are normally killed before the pupae emerge, either by pricking them with

66-450: A needle or dipping the cocoons into boiling water, thus allowing the whole cocoon to be unravelled as one continuous thread. This allows a much finer cloth to be woven from the silk. There are more than 500 species of wild silkworms in the world, although only a few (nearly all listed below ) are used to produce cloth. They usually produce a tougher and rougher silk than that from domesticated B. mori . Wild silks are usually harvested after

88-581: A new method was developed for demineralizing silk, which can remove the mineral reinforcements present in wild silks and enables wet reeling like the commercial silkworm. Wild silks are often referred to in India as 'Vanya' silks: The term 'Vanya' is of Sanskrit origin, meaning untamed, wild, or forest-based. Muga , Tasar, and Eri silkworms are not fully tamed and the world calls the silks they produce as 'wild silks'. India produces four kinds of silk: mulberry, tasar, muga and eri. The silkworm Bombyx mori

110-453: A paper-like fabric. Whole nests have also been use as purses and containers for liquid, and sections of nest silk have served as bandages and as a base for painting. Silk fibres from the same species have been extracted and spun to make sashes. This practice was recorded in Oaxaca in 1986, but had ceased by 1997. It is uncertain when the wild fibres were first used in this way; one hypothesis

132-408: A process called "throwing", which is drawn under tension through several guides and wound onto reels. This process of throwing produces various yarns depending on the amount and direction of the twisting. The threads may be plied to form yarn (short staple lengths are spun; see silk noil ). After drying, the raw silk is packed according to quality. The most popular substitute for traditional silk

154-444: A result. The cocoons of Tussar silkworms, which are found in open woodlands, are used to produce wild silk , also known as Tussar silk. Compared to conventional silk, their cocoons are typically picked after the moths have emerged, making it a more ethical option. Because wild silkworms consume a variety of plants, their fabric is less uniform but more robust. The fabric is made with fewer chemicals as well. The pupae are still inside

176-405: Is 130 tonnes. Production of other types of silk exceeds 10 000 tonnes (Gupta 1994). In 2015, the complete sequence and the protein structure of Muga Silk Fibroin was analyzed and published. The eri silk worm from India feeds on the leaves of the castor plant. It is the only completely domesticated silkworm other than Bombyx mori . The silk is extremely durable, but cannot be easily reeled off

198-449: Is a continuous filament comprising fibroin protein , secreted from two salivary glands in the head of each worm, and a gum called sericin , which cements the filaments. The sericin is removed by placing the cocoons in hot water, which frees the silk filaments and readies them for reeling. This is known as the degumming process. The immersion in hot water also kills the silkmoth pupa. Single filaments are combined to form thread , in

220-517: Is fed on mulberry leaves cultivated in plantations. Silkworms are also found wild on forest trees, e.g Antheraea paphia which produces the tasar silk ( Tussah ). Antheraea paphia feeds on several trees such as Anogeissus latifolia , Terminalia tomentosa , T. arjuna ( Terminalia arjuna ), Lagerstroemia parviflora and Madhuca indica . Antheraea assamensis produces muga silk , and another wild silkworm ( Samia ricini ) produces eri silk . The estimated annual production of tasar silk

242-485: Is generally thought to have had the oldest silk industry in the world. The specimens of threads from Harappa appear on scanning electron microscope analysis to be from two different species of silk moth, Antheraea paphia and A. assamensis , while the silk from Chanhu-daro may be from a Philosamia species ( eri silk ), and this silk appears to have been reeled. Wild silks were in use in China from early times. Moreover,

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264-574: Is peace silk, also known as ahimsa silk . The primary factor that makes this form of silk more ethical is that moths are permitted to emerge from their cocoons and fly away prior to boiling. It denotes that no pupa is ever cooked alive during manufacture. However, domesticated silkworms used to make silk have undergone thousands of years of selective breeding and are not "manufactured" to emerge from their cocoons. They are unable to defend themselves against predators since they cannot fly or see clearly. They typically die soon after emerging from their cocoons as

286-428: Is responsible for Bangladesh Sericulture Research and Training Institute and also manages state owned silk factories in Bangladesh. This article about a Bangladeshi organisation is a stub . You can help Misplaced Pages by expanding it . Sericulture According to Confucian text, the discovery of silk production dates to about 2700 BCE, although archaeological records point to silk cultivation as early as

308-571: The Second Crusade , Roger II of Sicily (1095–1154) attacked Corinth and Thebes , two important centres of Byzantine silk production, capturing the weavers and their equipment and establishing his own silkworks in Palermo and Calabria , eventually spreading the industry to Western Europe. The silkworms are fed with mulberry leaves, and after the fourth moult , they climb a twig placed near them and spin their silken cocoons . The silk

330-533: The Yangshao period (5000–3000 BCE). In 1977, a piece of ceramic created 5400–5500 years ago and designed to look like a silkworm was discovered in Nancun, Hebei , providing the earliest known evidence of sericulture. Also, by careful analysis of archaeological silk fibre found on Indus Civilization sites dating back to 2450–2000 BCE, it is believed that silk was being used over a wide region of South Asia. By about

352-621: The 1st century CE, obviously had some knowledge of how wild silkworms' cocoons were produced and utilised on the island of Kos for coa vestis , even though his account included some fanciful ideas. Wild silk was used and traded by the Aztecs , Mixtecs and Zapotecs at the time of Moctezuma (early 16th century CE). This silk came from the social caterpillars Euchiera socialis and Eutachyptera psidii , which produce communal silk nests that frequently reach 50 cm (20 inches) in length. The nests were cut open and pasted together to make

374-743: The Chinese were aware of their use in the Roman Empire and apparently imported goods made from them by the time of the Later Han Dynasty in the 1st to 3rd centuries CE. There are significant indications in the literature that wild silks were in use in Persia and in Greece by the late 5th century BCE, apparently referred to as "Amorgina" or "Amorgian garments" in Greece. Pliny the Elder , in

396-469: The cocoon and is thus spun like cotton or wool. Some of the best quality wild silk is produced by silkworms in Henan . This is the only type of wild silk that can be easily dyed. Wild silk threads have been found and identified from two Indus River sites, Harappa and Chanhu-daro, dating to c.  2450–2000 BCE . This is roughly the same period as the earliest evidence of silk use in China, which

418-923: The cocoons when they are harvested by certain enterprises that employ "wild silk", though. The stages of production are as follows: Mahatma Gandhi was critical of silk production based on the Ahimsa philosophy "not to hurt any living thing". He also promoted "Ahimsa silk", made without boiling the pupa to procure the silk and wild silk made from the cocoons of wild and semiwild silkmoths. The Human League also criticised sericulture in their early single " Being Boiled ". The organisation PETA has also campaigned against silk. The conventional method of silk production results in ~8 kg of wet silkworm pupae and ~2 kg of dry pupae per kilogram of raw silk. This byproduct has historically been consumed by people in silk-producing areas. Wild silk Wild silks have been known and used in many countries from early times, although

440-587: The first half of the 1st century CE, it had reached ancient Khotan , by a series of interactions along the Silk Road. By 140 CE, the practice had been established in India. In the 6th century CE, the smuggling of silkworm eggs into the Byzantine Empire led to its establishment in the Mediterranean, remaining a monopoly in the Byzantine Empire for centuries ( Byzantine silk ). In 1147, during

462-552: The moths have left the cocoons, cutting the threads in the process, so that there is not one long thread, as with domesticated silkworms. Wild silks are more difficult to bleach and dye than silk from Bombyx mori , but most have naturally attractive colours, particularly the rich golden sheen of the silk produced by the muga silkworm from Assam , often known as Assam silk . The cocoon shells of wild silk moths are toughened or stabilized either by tanning (cross-linking) or by mineral reinforcements (e.g. calcium oxalate ). In 2011,

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484-400: 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. Silk taken from various species has been used since ancient times, either in its natural state or after some form of preparation. Spider webs were used as a wound dressing in ancient Greece and Rome, and as

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