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.

The cocoon is made of a thread of raw silk from 300 to about 900 m long. The fibers are fine and lustrous, about 10 um in diameter. The number of cocoons required to produce a final yield of silk