273 



NOTES ON THE CULTIVATION OF THE JAPANESE OAK-FEEDING 

 SILK- WORM (Antherea yama mai). 



BY C. E. WEBSTEK, M. D. 



The subject of this paper is oue that has CDgaged the attention of 

 the writer through a period of several years, and affords many pleas- 

 ant recollections. 



The eggs of the Yama mai are deposited singly or in small groups. 

 Their tenacious brown envelope serves to fasten them to the spot when 

 they are deposited, to occlude the iniuute pores which perforate the 

 shell, thus controlliug the evaporation of the contained iiuids, and also 

 as a disguise to conceal them froni birds and other enemies, rendering 

 them inconspicuous upon the rough twigs of the oak. In shape they 

 are flattened spheroids, the greater diameter beiug 3""" and the lesser2"'"'. 

 They are deposited in the latter part of August. Those which are 

 sterile begin to flatten out in a few days and finally collapse, while those 

 that are fertile, if carefully opened by cutting oft oue face of the disk, 

 will show the developing embryo. 



The worm is fully formed loug before cold weather sets in, and lies 

 throughout the winter in a dormant state curled up within its neatly 

 varnished case. 



The eggs are commercially known as seed. I obtained ray seed from 

 Mr. W. Y. Andrews, of New York, in the fall of 1872. He probably 

 obtained the stock from England. Originally the species was brought 

 from Japan by the French Acclimatization Society about the year 1860. 

 The first stock was lost, and later a representative of the Dutch Gov- 

 ernment obtained a fresh supply, from which many crops were raised in 

 different parts of Europe. 



I placed the eggs in a bottle and hung them outside a north window. 

 There they remained until the following spring. When warm weather 

 came, fearing that they would hatch before their food-plant, the Uak, 

 was in leaf, the bottle was lowered into a well and occasionally exam- 

 ined. All remained quiet until the middle of May, when there appeared 

 three or four little caterpillars. 



The Oak was not yet out. It is stated* that they will eat the leaves 

 of the Chestnut, Quince, Pyrus terminalis and P. aria (species allied to 

 the Mountain Ash) and also that they will eat the leaves of the Pear.t 



The young worms were placed upon the pear leaves and ate vigor- 

 ously, but this food brought on an attack of diarrhoea, a regular cholera 

 infantum, from which they died, victims of circumstances and an un- 

 natural diet. A few days later the little reddish, fuzzy oak leaves were 

 out of bud, more caterpillars were crawling about in the bottle and the 

 work of attending an interesting family of fifty began in good earnest. 



*Der Japauiscbe Eichenspinner. Von Ad. UUerich. 

 tin Mr. Andrews' circular. 



