The larva of any one of numerous species of bombycid moths, which spins a large amount of strong silk in constructing its cocoon before changing to a pupa. [1913 Webster
" The common species (Bombyx mori) feeds on the leaves of the white mulberry tree. It is native of China, but has long been introduced into other countries of Asia and Europe, and is reared on a large scale. In America it is reared only to small extent. The Ailanthus silkworm (Philosamia cynthia) is a much larger species, of considerable importance, which has been introduced into Europe and America from China. The most useful American species is the Polyphemus. See Polyphemus."