Silk worm production
The silkworm isn�t really a worm, ... it's a caterpillar! The silkworm has been used by people for over 4,000 years to make silk. The practice first began in China in about 2600 BC. The Chinese kept the secret of producing silk for thousands of years, trading silk to Europe and the Middle East. But eventually the secret of how to get silk from the silkworm was learned by other countries. More recently we have learned how to make silk-like material from synthetic materials, but the demand for real silk is still high, and silkworms are still raised for the silk threads they produce.
The practice of raising silkworms is called sericulture.
The silkworm, when fully grown, reaches a length of about 5 to 7 centimetres, and it's an amazing worker. In only a few days, a single silkworm spins a cocoon from which can be removed a silk thread up to 600 metres in length. But it still takes about 25,000 cocoons to make half a kilogram of raw silk. Most of the silk today is produced by China and India, and a few other countries. 60,000 tonnes of raw silk are made each year, and are turned into dresses, shirts, bed sheets, curtains, and other products. It's a big industry, especially in China, where ten million Chinese farmers grow silkworms, and another half million make silk fabrics. There are 600 silk weaving mills in China.
Around the world there are different varieties of silkworm used to make different types of silk; there is even one type of silkworm that makes a coccoon together with another silkworm, producing a double-thread! Although synthetic fibers such as nylon and polyester, which are stronger than silk and lower in price, have turned silk into a luxury product, silk is still in demand because of its superior look and feel.
