The silkworm is the larva or caterpillar of the domesticated silkmoth, Bombyx mori (Latin: "silkworm of the mulberry tree"). It is an economically important insect, being a primary producerof silk. A silkworm's preferred food is white mulberry leaves, but it may also eat the leaves of any other mulberry tree (i.e., Morus rubra or Morus nigra) as well as the Osage Orange. It is entirelydependent on humans for its reproduction and does not occur naturally in the wild. Sericulture, the practice of breeding silkworms for the production of raw silk, has been underway for at least 5,000years in China, from where it spread to Korea and Japan, and later to India and the West.
Eggs take about fourteen days to hatch into larvae, which eat continuously. They have apreference for white mulberry, having an attraction to the mulberry oderant cis-jasmone. They are not monophagous since they can eat other species of Morus as well as some other Moraceae. Their droppings areblack. Hatchlings and second-instar larvae are called kego and chawki in India. They are covered with tiny black hairs. When the color of their heads turns darker, it indicates that they are aboutto molt. After molting, the instar phase of the silkworm emerges white, naked, and with little horns on the backs.
After they have molted four times (i.e., in the fifth instar phase), their bodies becomeslightly yellow and the skin become tighter. The larvae will then enter the pupa phase of their life cycle and enclose themselves in a cocoon made up of raw silk produced by the salivary glands. Thecocoon 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 Bombyx genus,and the Saturniidae, in particular the Antheraea genus—have been exploited for fabric production.
If the animal is allowed to survive after spinning its cocoon and through the pupa phase of its...