THE STATE ENTOMOLOGIST. 



133 



The cocoon (Fig. 58) is large, 

 heavy and handsome, and requires a 

 full week for its completion. It is 

 formed within a single leaf or 

 within several drawn together and 

 attached to a twig. It is oval and 

 usually of a bright golden-yellow 

 color on the outside though nearly 

 white inside. Those raised out-of- 

 doors are more green, wdiile those 

 raised in-doors are more yellow, 

 and white specimens have already 

 been produced. The silk is strong 

 and valuable; it bleaches well 

 and may then be dyed; fewer 

 (threads are required to make a 

 strand than in that of mori, and it 

 unwinds with perfect facility, by 

 the ordinary process. ' It shows its 

 afftnit}^ to that of our Polyphemus 

 by the gum which surrounds it coutaining a chalky or calcareous substance 

 which may be noticed upon tearing or rubbing the cocoon. 



The Moth (Fig. 55, male) is magnificeift in point of size and color. 

 The front wings are broadly falcate and more so in the male than in the 

 female. The collar and broad costal margin are always of an ash-gray- 

 The eye-spots are surrounded with more or less pink and yellow, white and 

 black, the black always being on the outside. The broad lines across the 

 wings are either wavy and slate-colored, with an inner wavy coincident 

 shade, or more straight with a whitish outer shade, relieved b}^ a darker 

 more reddish posterior shade. The posterior margins are either paler than 

 the general surface, or ornamented with a dark wavy line. The median 

 shade across front wings is either very distinct and scolloped, or obsolete j 

 and there is either one or two such shades on the hind wings. The species 

 varies, in fact, very much in the detail of ornamentation, and in general 

 color, being either yellow, brown, grayish or olivaceous, and some speci- 

 mens much resembling certain forms of our Polyphemus. 



According to the testimony of those who have had most experience 

 with this species in Europe, coition invariably takes place at night, and 

 lasts but a comparatively brief time. As the moths issue very irregularly 

 and the males are apt to appear many days before the females, and as it has 

 been further ascertained that unless they emerge within a day or so of each 

 other, the sexes show little affinity ; it is best to retard the male cocoons. 

 This can be done by first separating them, by weighing as described on 

 page 97, and keeping the male cocoons in a cooler place than those of the 

 female 



From the foregoing it is evident that while yama-mai is the most valu- 

 able silk producer next to mori, it is nevertheless very difficult to rear. It 



