188 Fiftieth Report on the State Museum 



It will be seen by consulting it, that the shortest period between the 

 spinning up of the larva and pupation was but three days, — the longest 

 fifteen, and the average a little over seven days and one-half. The 

 shortest period of pupation was twenty-five days, and the longest sixty 

 — the average being nearly thirty-eight days. 



The Pupa. 



The larva spins a thin netting of yellowish silk with little amber beads 

 at the joining of the threads just before pupating. No description of the 

 pupa was made, but it has been described by Dr. Dyar as follows : 



" Robust, of normal shape; on the abdominal segments, dorsally and 

 subventrally are ten rows of large tufts of short spiny hairs, the tufts 

 smaller ventrally and less numerous posteriorly; cremaster, two tufts of 

 reddish spines from elevated bases. Color black, reddish in the abdo- 

 minal incisures; the body is smooth and dull, the wing cases more shiny, 

 creased. Spiracles linear, reddish. Length 35 mm., width 13 mm." 



The Imago. 



This beautiful insect with a wing-spread of from two and three-quarter 

 inches in the male to three and a half in the female is a desirable addition 

 to the cabinet of a collector. Its lustrous blue abdomen marked with 

 orange down the middle and on the sides, and the sharp black markings 

 of the thorax and wings on a white background, give the insect a striking 

 appearance. There is considerable variation in the markings in difterent 

 individuals as will be seen on plate i, and particularly so when the 

 sexes are compared. The irregular black rings that adorn the thorax 

 and wings of the female, tend to become black spots in the male, as 

 seen in figure 2 of plate i. More often, however, the costal and some 

 of the smaller discal rings on the wings and those of the thorax are re- 

 placed by spots (see figures). It will also be noticed that the posterior 

 thoracic spots of the male are frequently blue, while in the female the 

 corresponding marking are a much darker blue or a black. 



A variety of this species, denudata Slosson, in which the tips of the 

 primaries are invariably denuded, has been described from Florida. 



Life-History. 

 So far as known there appears to be but a single annual generation. 

 The nearly full-grown larva are commonly observed in the autumn, and 

 in this stage usually hibernate. Trie caterpillars can successfully with- 

 stand a great degree of cold. They may even be revived after having 



