No. 3. ] Silkworms in India. 163 



ERI. 



Attacus ricini, 1 Boisd. 

 [ Plate VIII (a). ] 



This is a multivoltine silkworm which is fed on the leaves of the 

 eastor-oil plaut and reared entirely indoors in Assam, much in the way 

 that the mulberry worm is reared in Bengal. It is cultivated throughout 

 the whole of Assam, particularly in the submontane districts, the indus- 

 try being mostly in the hands of non-Hindu tribes of low caste. 



Each female moth lays about £00 eggs, which, under favourable cir- 

 cumstances, hatch in a week to a fortnight after being laid ; the worm 

 molts four times, and becomes full-grown and commences to spin in a 

 fortnight to a month after emerging from the egg. The moth emerges and 

 lays its eggs in a fortnight to a month after the formation of the cocoons. 

 The cycle of existence of the insect, in its various stages, thus takes from 

 5 to 11 weeks to complete j this variation being chiefly due to temper- 

 ature, cold retarding and heat accelerating the process, as is the case with 

 the mulberry worm of Bengal. As many as eight generations of the insect 

 <jan thus, under favourable circumstances, be gone through in the year but 

 the number actually reared does not exceed five or six. Most of the 

 rearing goes on iu the cooler portion of the year, the chief crops of co- 

 coons being generally obtained in November, February, and May, respect- 

 ively, and worms being reared during the rains, more to keep up the 

 stock than to produce silk. 



The cocoons are somewhat loose in texture and either white or deep 

 brownish red iu colour. Those of them that are intended to be made into 

 silk are stifled, either by exposure to the sun or over a fire ; and when re- 

 quired for manufacture, the chrysalids are cut out, and the silk cocoons 

 softened by boiling in some alkaline solution. The silk is spun, by hand, 

 into a more or less uneven thread, which is woven locally into a coarse 

 but particularly soft and durable cloth. Reeling of the cocoons, though 

 possible, is not adopted. 



A most complete account of the insect has been given by Stack in his 

 report, dated February 1884, on silk in Assam. The following there- 



1 The following is the synonymy of the species : — 



Saturnia ricini, Boisd. Ann. Soc. Ent., France, 1854. 

 Attacus lunula, Walker, B. M. Cat., 1855. 

 Philosamia lunula, Butler, III. Typ. Sep. Het. B. M. V., 1881. 

 Attacus ricini, Moore, Cat. Lep. Mus., E. I. C, 1859. 



Hutton, Journ. Agri. Hort. Soc. Ind., 1871. 



WarDford-Lock, Journ. Soc. Arts, 1880. 



Wardle, Wild Silks of India, 1881. 



Stack, Silk in Assam, 1884. 



Bondot, L'art de la Sow, 1887. 



