Wild silks

Tussah (wild silk) Silkworms other than Bombix mori... 

The larvae of Bombyx mori, the cultivated moth from which most silk has long been and still is made, feed on leaves of mulberry trees. In addition to cultivated silk, small quantities of "wild silk," also known as nonmulberry silk, have been derived in many parts of the world from the cocoons of moths other than Bombyx mori. Table 90 lists wild silks and the insect species that produce them (Peigler 1993 Jolly et al. 1979). 

Inoue, S., Tsuda, H., Tanaka, T., Kobayashi, M., Magoshi, Y., and Magoshi, J. (2003). Nanostructure of natural fibrous protein In vitro nanofabric formation of Sarnia cynthia ricini wild silk fibroin by self-assembling. Nano Lett. 3, 1329-1332. 

Tuskes, PM., Tuttle, J.P. and Collins, M.M. (1996). The Wild Silk Moths of North America. Ithaca, NY Cornell University Press. 

Fibres of Animal Origin.—Textile fibres of animal origin are principally sheeps , goats and camels wool, that of certain Camelidae, ordinary silk and wild silk. Table LIII gives the main microscopic characters used for their recognition. 

Wild silk. Ribbon.like with clear, longitudinal striae and transverse bundles Absent Mylitta 32 Yama-mai 40... 

Natural Silks. Many lepidopterous insects secrete from special glands a liquid which becomes solid in the air in the form of filaments destined for the construction of the cocoons in which the insects pass one stage of their existence. Ordinary silk is derived from Bombyx mori, and wild silk from other insects (Antheraea myliUa, A. Yama-mai), which live wild particularly in India, China and Japan. 

Although apparently quite smooth and homogeneous, the fibres of ordinary silk show, when examined with a high magnification and with the aid of special disaggregating reagents, very fine longitudinal striation due to the fibrillary structure proper to all silks. This structure is especially apparent in wild silks even under a low microscopic power. 

With weighted silk dyed black it is necessary to prolong the immersion to ij minute and with wild silk to 2-3 minutes. The zinc chlondc may be replaced by Lowe s solution, m which the fabric is immersed completely for about 2-3 hours in the cold. A better plan consists in making two determinations, one with zinc chloride and the other with Ldwe s solution. 

The first PBPs to be discovered were from wild silk moths Antheraea polyphemus (Vogt and Riddiford, 1981) and Antheraea pernyi (Kaissling and Torson, 1980)... 

Tussah or wild silk is obtained from caterpillars that are not cultivated, living naturally on mulberry, cherry, or oak trees. The cocoons are gathered by and processed by hand, resulting in an uneven and irregular product. Tussah is tan or brownish, depending on where the caterpillar had been living and what it had been eating. Tussah is often mixed with other fibers to produce hybrid fabrics. 

Chemicals Mulbery silk Wild silk (tussah, muga, eri)... 

Silks derived from moths other than Botnhyx viori, which do not feed on mulberry leaves, are classified as Wild silks. There arc many wild silks in existence but only a few have found limited commercial use. In Japan a species known as Antheraea yama-mai feeds on oak leaves and produces a thread which, in the past, found some uses. In India, Antheraea myiitia also finds nourishment from oak leaves, and Atlaais ricini thrives on the foliage of the castor-oil plant. 

The best-known wild silk is tussur, produced by Antheraeapernyiwhrch thrives on a diet of oak leaves and is found in China. I he worm is about 5 J in. long when mature and makes a compact cocoon which has a brownish colour. Spinning tends to be intermittent so that the filament is more broken than that of Bombyx mori, and for this reason it is more suitable for spun yarns. 

Tussur and other wild silks require special treatment. Tussur silk, in particular, is so difficult to bleach that it is commonly used in its natural fawn colour. Bleaching in a 0-6 per cent w/w solution at 70°, C (158°F) for 6 hours will give a fairly good white without excessive loss of tensile strength. The colour is improved by after-treatment in a liquor containing 2 g per litre of sodium hydrosulphite at 100°C. Silk can be bleached by stoving with sulphur dioxide, but the method has now virtually fallen into disuse. Treatment with sulphur dioxide after a peroxide bleach is sometimes used for exceptionally good whites. 

Wild silk (Tussah) production cannot be reeled, because cocoons are harvested after the moth has matured and left. As an average yield one may take 30 kg mulberry leaves for 1 kg cocoon. As the harvesting of the silk from the cocoon requires the killing of the larvae, silk-culture has been criticized by animal rights activists. 

Honan ho- nm n. A pongee-type fabric of the very best Chinese wild silk. Honan is sometimes woven with blue edges. 

Collins, M. M. and Weast, R. D. (1961) Wild Silk Moths of the United States. Satur-niinae. Collins Radio Company, Cedar Rapids, Iowa. 

Silk - fild silk, sometimes known as Tussah Silk is produced from silkworms that feed on the leaves of dwarf oak trees and are allowed to live out a complete lifecycle in their natural habitat. The silkworms are hmnanely cultivated, meaning the wild silk cocoons are only processed using natural methods and only after the moth emerges naturally from the cocoon. Hmnanely produced silk is also known as Peace Silk. ... 

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