Ho. 2. ] Wild Silk Insects of India. 85 



feet ia Sikkira tliroug-h October and November. It spins a rough 

 open cocoon on the ground at the foot of the food plant, the moth 

 emerging in the following August. 



The figure is from a specimen determined by Mr, H. J. Elwes. 



Brahm^a certhia, Fabr. Plate 15, fig. 1 (Ent. Syst. iii, I, p. 412, 



1793). 



This species is represented in the Museum Collection by specimens 

 from Sikkim and Shillong. Nothing seems to have been recorded of 

 its habits or development. Three closely allied forms — B. wJiiiei 

 Butler, from North- West India, B. conchifera, Butler, from Sylhet and 

 Darjiliiig, B.wallichii, Grray, from Assam and Nepal — have been figured 

 by Butier (111. Typ. Lep. Het. B. M. V, pi. 95, figs. 1, 2, 3, 4, 5, and 6). 

 They appear to be so closely related to B. certhia as to be scarcely distin- 

 guishable from it. A fourth form — B, ntfescens — Butler, from North- 

 East Bengal, has been described (Ann. Mag. N. H. 5, VI, p. 62, 1880) 

 as related to, and in some respects intermediate between, the others. It 

 seems most convenient to await further observation on the habits and 

 life histories of these insects before endeavouring to separate them 

 into distinct species. 



The figure of B. certhia is from a specimen determined by Mr. H. 

 J. Elwes. 



Theophila hdttoni, Westw. Plate 15, fig. 3, 



This is a bivoltine species, which is common upon wild mulberry trees 

 on the lower slopes of the North- West Himalayas. The caterpillars of 

 the first generation, according to Hutton (Trans. Ent. Soc, Lend. , 3, ii, 

 1864 — 66; and Journ. Agri. Hort. Soc, Ind., Ill, 1871), appear about 

 April, and the cocoons are formed in May and September respectively. 

 The insect hibernates in the form of eggs glued on to the bark of its food 

 plant. The cocoon is whitish in color and of soft loose consistence, not 

 unlike the cocoons of some Bengal Bomhyx silk worms, but much less 

 compact ; it is formed between the leaves of the food plant. The silk is 

 of excellent quality, and, according to Cope (Rondot, L'Art de la Soie, II 

 p. 6), can be reeled ; so, if it could be obtained in any considerable quan- 

 tities, there^is little doubt but that it would be of value. Hutton^s attempt, 

 however, to cultivate it for commercial purposes proved unsuccessful, as 

 the worms were too restless to submit to domestication in the house, and 

 when left at liberty upon the trees were so much attacked by birds and 

 predaceous insects as to render the yield of silk unprofitable. It is possi- 

 ble that the restlessness exhibited by the worms, when under cover, may 

 have been due to want of the moisture to which they are ordinarily ex- 

 posed on the hill slopes -, this having proved to be the case with tusser 



