Lepidoptera feathers and hair, bran, semolina and flour (possibly preferring wheat flour), biscuits, casein, and insect specimens in museums. Even though most butterflies and moths affect the economy negatively, some species are a valuable economic resource. The most prominent example is that of the domesticated silkworm moth ("Bombyx mori"), the larvae of which make their cocoons out of silk, which can be spun into cloth. Silk is and has been an important economic resource throughout history. The species "Bombyx mori" has been domesticated to the point where it is completely dependent on mankind for survival. A number of wild moths such
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