Instruct: Given a question, retrieve relevant documents that answer the question.
Query: When do silk worms form cocoons?
After they have molted four times, their bodies become slightly yellow and the skin becomes tighter. The larvae then prepare to enter the pupal phase of their lifecycle, and enclose themselves in a cocoon made up of raw silk produced by the salivary glands. The final molt from larva to pupa takes place within the cocoon, which provides a vital layer of protection during the vulnerable, almost motionless pupal state. Many other Lepidoptera produce cocoons, but only a few—the Bombycidae, in particular the genus Bombyx, and the Saturniidae, in particular the genus Antheraea—have been exploited for fabric production.
On the same visit he went in 1886 to Kashmir, where silk production was in a poor state. He had ideas for its revival, which on his return home he presented to the government; eventually in 1897 he purchased in Europe large amounts of silk-worm eggs and cocoon-reeling machinery for Kashmir, which revived the silk industry there.
The tree is a major food source for the mopane worm, the caterpillar of the moth "Gonimbrasia belina". The caterpillars are rich in protein and are eaten by people. The tree also acts as a foodplant for a wild silk moth, "Gonometa rufobrunnea". Cocoons of the moth are harvested as wild silk, to make cloth.
Copulation and reproduction are separate processes in earthworms. The mating pair overlap front ends ventrally and each exchanges sperm with the other. The clitellum becomes very reddish to pinkish in color. Some time after copulation, long after the worms have separated, the clitellum (behind the spermathecae) secretes material which forms a ring around the worm. The worm then backs out of the ring, and as it does so, it injects its own eggs and the other worm's sperm into it. As the worm slips out of the ring, the ends of the cocoon seal to form a vaguely onion-shaped incubator (cocoon) in which the embryonic worms develop.
In order to kill the silkworms, the cocoons are dried in the sun. A variation of the process exists in which the silkworms are allowed to leave before the cocoons are soaked in boiling water to soften the silk and then reeled. Single-shelled, oval-shaped cocoons are collected and then boiled to extract the silk yarn. Boiling is a very important part in the manufacturing of silk, as it softens the cocoon and makes the extraction of silk easier. In conventional sericulture, the cocoons are boiled with the larvae still inside; however, if the cocoons are boiled after the larvae have left them, the silk made is then called "non-violent silk" or "Ahimsa silk". In China, the silks are given different names when silkworms are reared on different plants, as the diet of the silkworms has an effect on the quality of the silk. For example, silk from larvae on the wild mulberry is called "zhe", while those on the oak "Quercus dentata" produce "hu".
The Suzhou Silk Museum is a museum in Suzhou, China. It documents the history of silk production and Suzhou embroidery from around 2000 BC. Exhibits include old looms with demonstrations, samples of ancient silk patterns, and an explanation of sericulture. Of major note is a room full of live silk worms, eating mulberry leaves and spinning cocoons. By December, 2009, the live silkworms had been replaced with models.
The eri silk worm is the only completely domesticated silkworm other than "Bombyx mori". The silk is extremely durable, but cannot be easily reeled off the cocoon and is thus spun like cotton or wool.
When the worms have grown enough, they are put in baskets. From there, they will spin their cocoons in five days and will produce about three hundreds meters of silk each. The cocoons are then put in sunlight to avoid them undergoing their metamorphosis into mature moths. However, 20% of them reach the breeding process and the female moths will lay and hatch its eggs within nine to twelve days.
The cocoons are soaked in hot water in order to soften the sericin (also known as silk gum) which coat the fibres and stick the cocoons together. Silk threads are then unwound and reeled together to produce a single thread. Weavers at Angkor Silk Farm make both raw silk and fine silk that do not have the same texture at all. Sericin has not been completely removed from raw silk threads, which will give a rougher texture to the fabric at the end.
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.
Demineralizing has the potential to be used in the silk sector enabling wet reeling of Wild Silk moth cocoons by removing the mineral layer present in these cocoons. This technique is not like degumming where the gum of the fibroin fibres is removed what would lead to a tangled cocoon. With "demineralizing" the gum and structure of the cocoon is kept intact enabling the cocoons to be wet reeled. This could allow a new silk industry in areas which have not the conditions or infrastructure for raising the domesticated silk worm "Bombyx mori", possibly generating a revolutionary new income stream and alleviating poverty
The writings of Confucius and Chinese tradition recount that, in about 3000 BC, a silk worm's cocoon fell into the tea cup of the empress Leizu. Wishing to extract it from her drink, the 14-year-old girl began to unroll the thread of the cocoon.
Eri silk is a staple fiber, unlike other silks, which are a continuous filament. The texture of the fabric is coarse, fine, and dense. It is strong, durable, and elastic. Eri silk is darker and heavier than other silks and blends well with wool and cotton. Due to its thermal properties it is warm in winter and cool in summer. The fibre is "cottony", not glossy like mulberry silk. The cocoons of eri silkworms are open-ended, meaning the grown larva can leave via the opening. This has led to eri silk being termed "peace silk" as its production harms no living organisms. Mulberry silkworms, on the other hand, make a hole in the cocoon when emerging as moths, thus damaging the silk. To forestall the damage, processors boil the mulberry cocoons to kill the larva, leading organisations such as PETA to blacklist mulberry silk.
The production of Thai silk begins with the "Bombyx mori", a small silk worm that comes from the eggs of a silk moth. For their first year, these worms feast on the leaves of mulberry trees before building a cocoon with their spittle.
Silk reeling (pinyin chánsī, Wade-Giles ch'an² ssu 纏絲) refers to a set of neigong (内功, "internal") movement principles expressed in traditional styles of t'ai chi ch'uan (太極拳), but especially emphasised by the Chen 陳 and Wu 吳家 styles. The name derives from the twisting and spiralling movements of the silkworm larva as it wraps itself in its cocoon, and to the metaphorical principle of "reeling the silk from a silk worm's cocoon". In order to draw out the silk successfully the action must be smooth and consistent without jerking or changing direction sharply. Too fast, the silk breaks, too slow, it sticks to itself and becomes tangled. Thus silk reeling movements are continuous, cyclic, spiralling patterns performed at constant speed with the "light touch" of drawing silk. Silk reeling is trained in solo forms and stances as well as in pushing hands with a partner.
An aqueous 1 M solution of ethylenediaminetetraacetic acid (EDTA) is used adjusted to pH 10 with saturated sodium hydroxide solution. The cocoons are immersed in this solution for 72 h at 40 °C and gently stirred. During the process, the cocoons are kept under the surface of the solution by means of a plastic mesh, using a partial vacuum to encourage penetration of the solution. Afterwards, the cocoons are thoroughly washed with running tap water (three times 3 h) and subsequently reeled in tap water at room temperature using the standard method for "Bombyx mori". The method described here forms the basis of a patent application.
During earlier times, people used to obtained silk from silk worms, which feed on mulberry trees. Pure silk was obtained from silk cocoons by rough means without any technical expertise. The practice of silk production is nonexistent now. Now the people are more engaged with Apple and other business activities.srigufwara is one of the town in South Kashmir which is developing at faster pace in all aspects
Fruit Growers
The process of silk production is known as sericulture. The entire production process of silk can be divided into several steps which are typically handled by different entities. Extracting raw silk starts by cultivating the silkworms on mulberry leaves. Once the worms start pupating in their cocoons, these are dissolved in boiling water in order for individual long fibres to be extracted and fed into the spinning reel.
The California Silk Center Association was formed with a large capital on paper. The association bought which now form part of Riverside. It was the intention of the association to found a colony there of silk growers and silk weavers. Sixty families were reported ready to locate on the colony grounds as soon as negotiations were completed. Prevost, the leader of the group, died shortly after the purchase was made, and the colony project died later. At first, the profits from the seri-culture fad were large, not, however, from the manufacture of silk, but from the sale of silkworm eggs. When the industry was launched, eggs sold at ten dollars an ounce and the worms were good layers. One seri-culturist reported a net profit of US$1,000 an acre made in sixty days from the sale of eggs. Another realized US$1,260 an acre in a single season. The net profits from his three acres of trees and cocoons exceeded the net profit on his neighbor's 10,000 acres of grain. With such immense returns from such small investments, it is not strange that the sericulture craze became epidemic. Mulberry plantations multiplied until the bounties paid threatened the state treasury with bankruptcy; in 1867 or 1868, the law was repealed. Out of the hundreds of thousands of bounty-bought cocoons, only one piece of silk was known to be manufactured, and that was a flag for the State Capitol. Counting bounties paid and labor lost on a non-producing industry, indirectly that flag cost the people of the commonwealth not less than US$250,000. 
According to one account, a silkworm cocoon fell into her tea, and the heat unwrapped the silk until it stretched across her entire garden. When the silk ran out, she saw a small cocoon and realized that this cocoon was the source of the silk. Another version says that she found silkworms eating the mulberry leaves and spinning cocoons. She collected some cocoons, then sat down to have some tea. While she was sipping a cup, she dropped a cocoon into the steaming water. A fine thread started to separate itself from the silkworm cocoon. Leizu found that she could unwind this soft and lovely thread around her finger.
In its original cocoon form, raw silk is bumpy and irregular. Thai weavers separate the completed cocoons from the mulberry bush and soak them in a vat of boiling water to separate the silk thread from the caterpillar inside the cocoon.
Ramanagara is well known for its sericulture, and is nicknamed Silk Town and Silk City . The silk produced in this region forms the input for the famous Mysore Silk. Ramanagara is the largest market for silk cocoons in Asia. 50 tonnes of cocoon a day arrive at the town. Ramanagar has extensive granite sites.
Santuk Silk Farm is a silk farm, located about 11 miles (18km) southeast of Kampong Thom City, Cambodia, near the village of Kakaoh. The farm, established by Vietnam War veteran Bud Gibbons in 2006, demonstrates the process of the silk worm, from its earliest stages, from egg to cocoon. The farm employs some 15 girls to weave the raw silk into thread; they make scarves and other items, sold in the shop on site.
Silk comes from the cocoons of the silkworm, which feeds off mulberry trees in subtropical climates. When the cocoon is boiled, the hard cocoon becomes a loose ball of strong, flexible filament measuring over 1,000 meters. Usually, this ball is uncoiled and wrapped on a spindle for use in the textile industry. Silk is used for making everything from clothing to rugs. During silk comforter production, however, the silk filament is not unraveled, but rather stretched into a flat tangled web and layered to form silk floss, which will fill the comforter.
Most larvae spin a silken cocoon in the leaves of a preferred host plant or in leaf litter on the ground, or crevices in rocks and logs. While only moderately close relatives to the silkworm ("Bombyx mori") among the Lepidoptera, the cocoons of most larger saturniids can be gathered and used to make silk fabric. However, larvae of some species – typically Ceratocampinae, like the regal moth ("Citheronia regalis") and the imperial moth ("Eacles imperialis"), burrow and pupate in a small chamber beneath the soil. This is common in the Ceratocampinae and Hemileucinae. Unlike most silk moths, those that pupate underground do not use much silk in the construction. Once enclosed in the cocoon, the caterpillar sheds the larval skin and becomes a pupa, and the pupa undergoes metamorphosis for about 14 days, at which point it either emerges or goes into diapause. During metamorphosis, respiratory systems will stay intact, the digestive system will dissolve, and reproductive organs will take form.
Silk moths lay eggs on specially prepared paper. The eggs hatch and the caterpillars (silkworms) are fed fresh mulberry leaves. After about 35 days and 4 moltings, the caterpillars are 10,000 times heavier than when hatched and are ready to begin spinning a cocoon. A straw frame is placed over the tray of caterpillars, and each caterpillar begins spinning a cocoon by moving its head in a pattern. Two glands produce liquid silk and force it through openings in the head called spinnerets. Liquid silk is coated in sericin, a water-soluble protective gum, and solidifies on contact with the air. Within 2–3 days, the caterpillar spins about 1 mile of filament and is completely encased in a cocoon. The silk farmers then heat the cocoons to kill them, leaving some to metamorphose into moths to breed the next generation of caterpillars. Harvested cocoons are then soaked in boiling water to soften the sericin holding the silk fibers together in a cocoon shape. The fibers are then unwound to produce a continuous thread. Since a single thread is too fine and fragile for commercial use, anywhere from three to ten strands are spun together to form a single thread of silk.