376 



[November, 1912. 



ERI SILK. 



The Bulletin of Agricultural Intelligence and of Plant Diseases 

 for September, 1912, has a very interesting account on the above subject 

 from which we take the following extract? :— The eri silk is a silk grown 

 in Assam and the cloth woven froni it is known as "Eudi" cloth. The 

 difference between this and other silk is that it cannot be reeled and 

 the cocoon is not formed of a long continuous thread but is spun by the 

 worm in layers. Eri silk will probably be extended to other parts of 

 India for cultivation on a small scale. 



Rearing. 



Eggs are obtained and kept in a tray-like vessel to which air is admitted. 

 In hot weather the trays should be coveted with a damp cloth and in 

 very cold weather similarly covered and kept in the sun. In hot weather 

 the eggs hatch in 7 days and in cold they may stay as long as 24 days. 

 When the worms are hatched they are transferred to feeding trays, with 

 a free circulation of air, they are kept covered during: the day and during 

 very cold weather kept in the sun just as the eggs. The management of 

 rearing is the same as that recommended for the common silk worm, witli 

 the exception of food which is the leaf of the castor plant. 



Spinning. 



The "Chandraki" Spinning Frame of Bengal used for mulberry 

 silk is successfully used but it takes up too mueli space. Another method 

 is to suspend cloth over horizontal bamboos so that long folds hang 

 down and to let the worms crawl into the folds to spin. Very clean 

 cocoons can be got this way and they are readily detached from the 

 cloth: the amount of silk wasted in cocoon formation is small. After 

 5 days in hot weather aud 8 in cold the cocoous are picked out and 

 spread evenly on trays. After 10 days in summer, or up to 40 days or 

 more in winter, moths come out. They are then placed in a covered 

 basket , after 24 hours the males may be thrown away and the females 

 placed in a separate basket in which they will lay eggs. Each female lays 

 about 80 eggs the first uight. Eggs laid after the third night should not 

 be kept. The empty cocoons are boiled in water in which a weight of 

 castor ash equal to the weight of silk is dissolved, until the cocoons are 

 soft throughout. 



The cocoons can be carded and spun like wool, or the silk may be spun 

 directly from the cocoons which yield f to f of their weight of thread. 



Duration of Life 



The whole life cycle from the laying of the eggs to the flight of the 

 moths varies from 37 to 85 days according to the weather but in the 

 winter the duration of a b.'ood may extend up to 100 days and over. 



The Eri worms are poly vol tine and rearing goes on all the year round. 

 The worms spin two kinds of cocoons — white and red-brown. A moth 

 lays eggs from which both wliite and brown cocoons are formed, but if 

 only the moths from white cocoons are bred the red cocoons will gradu- 

 ally disappear aud vice versa. White cocoons are preferred. 



