|Geographical Range||China (native range); introduced to other parts of Asia, Europe, and the Americas|
|Scientific Name||Bombyx mori|
|Conservation Status||Not listed by IUCN|
This animal is not really a worm, but the larval form of the silk moth. The famous "silk" that the insect produces is spun to make their cocoons. Each cocoon may contain a single strand of silk one mile long!
Silk threads, plucked from the cocoon of the mulberry caterpillar, have been woven into luxurious fabrics for more than 4,000 years. More than 10 million farmers raise silkworms today in China, producing about one-half of the world's supply. They hatch the caterpillars from eggs that are kept in cold conditions. The hungry caterpillars spend almost a month munching on mulberry leaves or artificial diets before they start to spin their cocoons.
At this point, each caterpillar is kept in its own box. It ejects a single protein thread as fast as one foot a minute, then coats it in a gummy liquid to shape its cocoon. Inside the cocoon, the caterpillar pupates (changes into a moth) in about two weeks. The cocoons are dipped into a hot steam bath and the thread is carefully unraveled and wound into skeins of silk.
Today, the silkworm moth is thought to live only in captivity. The species has been so genetically altered by humans that it can no longer survive independently in nature, particularly since the adults have lost the ability to fly. All wild populations are believed to be extinct, although presumably related forms may still exist in Asia.
Silk fabric was so valuable that the Chinese kept its production secret for hundreds of years.