Sericulture

silkworm and cocoon

Sericulture, or silk farming, is the rearing of silkworms for the production of raw silk. Although there are several commercial species of silkworms, Bombyx mori is the most widely used and intensively studied. According to Confucian texts, the discovery of silk production by B. mori dates to about 2700 BC, although archaeological records point to silk cultivation as early as the Yangshao period (5000 – 10,000 BCE). About the first half of the 1st century AD it had reached ancient Khotan, and by AD 140 the practice had been established in India. Later it was introduced to Europe, the Mediterranean and other Asiatic countries. Sericulture has become one of the most important cottage industries in a number of countries like China, Japan, India, Korea, Brazil, Russia, Italy and France. Today, China and India are the two main producers, together manufacturing more than 60% of the world production each year.

Production

Silkworm larvae are fed mulberry leaves, and, after the fourth moult, climb a twig placed near them and spin their silken cocoons. The silk is a continuous-filament fiber consisting of fibroin protein, secreted from two salivary glands in the head of each larva, and a gum called sericin, which cements the two filaments together. The sericin is removed by placing the cocoons in hot water, which frees the silk filaments and readies them for reeling. The immersion in hot water also kills the silkworm pupae.

Single filaments are combined to form thread. This thread is drawn under tension through several guides and wound onto reels. The threads may be plied together to form yarn. After drying the raw silk is packed according to quality.

Stages of production

The stages of production are as follows:

1. The silk moth lays eggs.
2. When the eggs hatch, the caterpillars are fed mulberry leaves.
3. When the silkworms are about 23 days old, they are 10,000 times heavier than when they hatched.

They are now ready to spin a silk cocoon.

1. The silk is produced in two glands in the silkworm's head and then forced out in liquid form through openings called spinnerets.
2. The silk solidifies when it comes in contact with the air.
3. The silkworm spins approximately 1 mile of filament and completely encloses itself in a cocoon in about two or three days but due to quality restrictions, the amount of usable silk in each cocoon is small. As a result, 5500 silkworms are required to produce 1 kg of silk.
4. The silk is obtained from the undamaged cocoons by brushing the cocoon to find the outside end of the filament.
5. The silk filaments are then wound on a reel. One cocoon contains approximately 1,000 yards of silk filament. The silk at this stage is known as raw silk. One thread consists of up to 48 individual silk filaments.

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  third stage of silkworm

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  silkworms on to Modern Rotary montage

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  silk cocoon in mountages

See also

• Magnanery
• Good Agricultural Practices

External links

• Smithsonian sericulture history
• Central Silk Board India
• Sericultural Research & Training Institute Mysore India
• Central Sericultural Germplasm Resources Centre Ministry of Textiles Government of India
• Sericulture India Development Gateway
• Cocoon Rates in Government Cocoon Market in India A.P.& Karnataka state
• Cocoon Rates in Government Cocoon Market in India Karnataka state
• Cocoon Rates in Government Cocoon Market in India TamilNadu state
• Silk worm Life cycle photos
• Silkfarmer Life and death
• Raising silkworms in your classroom, including photos