Wild silk used to produce cloth. They usually produce a tougher and rougher silk than that from domesticated "Bombyx mori" silkworms. Wild silks are usually harvested after the moths have left the cocoons, cutting the threads in the process, so that there is not one long thread, as with domesticated silkworms. Wild silks are more difficult to bleach and dye than silk from "Bombyx mori", but most have naturally attractive colours, particularly the rich golden sheen of the silk produced by the muga silkworm from Assam, often known as Assam silk. The cocoon shells of wild silk moths are toughened or stabilized
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