Stock Photo - Silkworm Cocoons,doonas. There is an intimate connection between the Mulberry and the silkworm. The silkworm’s or Mulberry moth’s scientific name, Bombyx mori reflects this close relationship with mori being derived from Morus. The silkworm has a relatively short life cycle, and if kept at 75oF. Eggs hatch and yield 1/8 inch-long larva that immediately start eating Mulberry leaves. They must be fed constantly since they will not seek food and rarely wander away. Over the next 2 months, they will reach a full size of 2 inches, having molted (shed their ´skin´ and growing) four times in the process. They then spend 5 days spinning a cocoon. The cocoon is composed of silk that is made in 2 silk glands within the body. The single threads from each gland are formed into a double thread by the silkworm’s mouthparts and spun around the body, totally encasing it. The continuous thread is hundreds of feet in length. Within 5 days of completing the cocoon the larva changes into a pupa and after another 20-24 days emerges as a moth. The moth escapes from the cocoon by emitting a liquid that digests away the silk enabling the moth to crawl out. The adult moths have no mouth parts and while they can flutter their wings, they cannot fly. After mating the male dies. Soon after laying her 300 eggs, the female also dies. Resham is the Hindi term for ´silk´. Silk is the filament secreted by the silkworm when spinning its cocoon, and the names for the threads, yarns, and fabrics made from the filament. Most comericial silk is produced by the cultivated silkworm, Bombyx mori, which feeds exclusively on the leaves of certain varieties of mulberry trees and spins a thin, white filament. Several species of wild silkworm feed on oak, cherry, and mulberry leaves and produce a brown, hairy filament that is three times the thickness of the cultivated filament and is called tussah silk. The silkworm constructs its cocoon when it is preparing to enter its chrysalis stage where it shall hibernate and become a butterfly or moth. The cocoon is made from a double filament of silk, wrapped layer by layer around the insect´s body and cemented by a gelatinous protein sericin. Cocoons vary greatly in quality. The higher the amount of sericin deposited on the filament, the lower the grade of filament. Broken cocoons or some that are spun by two caterpillars together, are also judged inferior, and their filament is used to make spun silk rather than raw-filament silk. After grading, the cocoons are placed in hot water to soften the sericin so that filament can be removed and wound on reels. Because single filaments are extremely fine, filaments from five to ten cocoons are wound together by twisting them together and sealing them with melted sericin. The reeled yarn is termed raw silk. The raw silk is usually too thin to be used for textile weaving; it is made into a heavier yarn through throwing, a plying process. The fiber is first twisted, then plied with another yarn and twisted again. Once this final process in spinning is completed, the yarn is ready for weaving. More than any other natural fiber, silk has an affinity for color. Dyes are applied either to the unwoven skein or the woven the fabric after degumming, the boiling off of the sericin. After dying, the skein of yarn or fabric is placed on a clothesline to dry. Kissan exhibition for agricultural goodies, Pune, Maharashtra, India.