Bombyx mori their lifecycle, and enclose themselves in a cocoon made up of raw silk produced by the salivary glands. The final molt from larva to pupa takes place within the cocoon, which 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 genus "Bombyx", and the Saturniidae, in particular the genus "Antheraea"—have been exploited for fabric production. If the animal is allowed to survive after spinning its cocoon and through the pupal phase of its lifecycle, it releases proteolytic enzymes to make a hole in
Bombyx mori and the wild "B. mandarina" can still breed and sometimes produce hybrids. Domestic silkmoths are very different from most members in the genus "Bombyx"; not only have they lost the ability to fly, but their color pigments are also lost. Mulberry silkworms can be categorized into three different but connected groups or types. The major groups of silkworms fall under the univoltine ("uni-"=one, "voltine"=brood frequency) and bivoltine categories. The univoltine breed is generally linked with the geographical area within greater Europe. The eggs of this type hibernate during winter due to the cold climate, and cross-fertilize only by spring, generating