About 75,000 tons of silk is produced annually worldwide. Silk forms a continuous filament (up to 1600 meters in length) composed of two strands of a macromolecular protein, fibroin, bound together by the protein sericin. It is spun by the larval stage of moths (silkworms) in the formation of their cocoons. Wild silk (tussah) is spun by silkworms (Antheraea pernyi) that have fed on oak leaves. Mulberry silk is produced, mainly in China, by domesticated silkworms (Bombyx mori) that have fed on mulberry leaves. Genetic selection has left the domesticated silkworm totally dependent on man for its survival, requiring intensive husbandry. Once the cocoons have been formed, the chrysalides are killed, the gum that binds the filament is softened, and the silk is removed in a process called reeling.
Was this article helpful?
Studies show obesity may soon overtake tobacco as the leading cause of death in world. Who Else Could Use 101 'Everyday' Ways to Lose 10 Pounds or more and Keep it Off! You've been putting it off too long. Hey, everyone needs to lose weight from time to time. You're no different!