Eri silk, also called endi silk, is second only to Chinese tussah in world production. The silkworms and silkmoths are entirely domesticated, and do not exist in nature. The eri silkmoth is Samia ricini (Anonymous), and it was derived hundreds (if not thousands) of years ago in Northeast India from Samia canningi (Hutton). Eri silk has been confounded in most of the literature with silks of Samia cynthia (Drury) from northeastern China (Chou 1990) and Samia pryeri (Butler) from Japan. These latter two have only been used on small scales historically. Samia cynthia is the well-known ailanthus silkmoth that was introduced to Europe in the 1850s and to the United States in 1861, but it is now virtually extinct in the United States (Peigler & Naumann 2003). Eri silkworms feed mainly on castor bean leaves (Ricinus communis), but they are reared on several other kinds of plant. The cocoons are large and puffy and contain a lot of silk. The moths do not fly, a result of centuries of domestication like we see for Bombyx mori. Most ericulture is in Northeast India, especially Assam, Meghalaya, Manipur, Nagaland, and Orissa (Chowdhury 1982). Ericulture is also well established in Thailand, Vietnam, southern China, and Brazil. Peigler and Naumann (2003) provided a detailed account of ericulture around the world, both historically and recent times. Japanese entrepreneurs introduced ericulture to Ethiopia in 2001 where it has become a successful cottage industry. Ethiopians have long been skilled at spinning and weaving cotton, and eri silk and textiles look and feel like cotton.
Textile collectors in the West may be familiar with the colorful and intricate weavings of Bhutan (Myers & Bean 1994). Eri silk has long been favored by Bhutanese, and vintage or antique pieces stated to be "wild silk" and "raw silk" are composed of eri silk. Researchers at Khon Kaen University in northeastern Thailand have perfected a method of reeling eri silk from the cocoons, and the fabrics they produce have a nice smooth feel and are more glossy than the spun textiles. Buddhist monks in Tibet, Bhutan, and Nepal often wear wrappers made of eri silk, and the lower classes and Tribal Peoples of Assam and Meghalaya commonly use eri silk for clothing and bedding. It is too heavy to be used to make saris, but is perfect for the chilly climate in the Himalayan foothills. Scarves and shawls that are all or partly composed of eri silk are available from internet suppliers.
Chou, I. 1990. A History of Chinese Entomology. (Translated by Siming Wang.) Tianze Press, Xian. 248 pp., 32 color plates.
Chowdhury, S. N. 1982. Eri Silk Industry. Directorate of Sericulture & Weaving, Gauhati, Assam. iii 177 pp., 28 figures.
Myers, D. K. and S. S. Bean, editors. 1994. From the Land of the Thunder Dragon: Textile Arts of Bhutan. Serindia Publications, London, and Peabody Essex Museum, Salem, Massachusetts. 247 pp.
Peigler, R. S. and S. Naumann. 2003. A revision of the silkmoth genus Samia. University of the Incarnate Word, San Antonio. 230 pp, 10 maps, 228 figs. (148 in color).