Silkworms are extinct in the wild, but captive populations exist throughout Asia and Australia. Their previous natural range was mostly within China. The natural populations were completely consumed by the demand for silk.
Besides becoming extinct in the wild, silkworms have been greatly altered by their domestication. The adult moths of the species can no longer fly, and their wings are useful only for mating displays.
The species is named for its caterpillars. They create the silk for which they are named when they pupate as protective cocoons. Most silkworms never reach adulthood, as they are boiled in their cocoons before emerging to separate out the silk.