No. 1. 



BOMBYCINE MOTHS OF NORTH AMERICA— PACKARD. 



245 



At the base of the thoracic legs is a black dot, not present at the base of the abdominal legs. 

 The tubercles are nearly of the same shape and relative size as in stage II, but the six dorsal and 

 four last abdominal (the dorsal ones on ninth and tenth segments) are slightly larger than the other 

 abdominal ones, while the spiracles are larger than before and black; the other black marks 

 are as before. 



Stage IV: One molted again the morning of July 1. Length 15-16 mm., one 20 mm. and 

 eventually becoming 25 mm. When observed an hour or two after casting its skin, the body 

 as before was pale lemon-yellow; the tubercles of the same color as before, i. e., pale greenish 

 yellow, except those of the lower lateral row, which are black on the trunk, but with the head or 

 end and the spines light greenish yellow. The dorsal and two lateral rows of black spots are as 

 before. The head and upper side of the prothoracic segments are shining honey-yellow, as is 

 also the ninth and tenth abdominal segments, while the body is covered with a whitish mealy bloom. 



The larva, which were reared in Brunswick, Me., from eggs laid in Brooklyn, seem to feed 

 sparingly and to grow slowly, and were fed at first with ailanthus, 

 and afterwards with wild plum. They became before molting again 

 very white, the bloom being thick and powdery, so that the honey-yellow 

 head and prothoracic plate, with the suranal plate, together with the 

 sides of the anal legs and upper part of the ninth abdominal segment, 

 contrast with the color of the body. 



In this stage the two anterior setiferous tubercles on the 

 suranal plate are still well developed, as are also their bristles. 



Stage V. — Molted July 15-18. Length 40 mm. It differs from 

 the preceding stage in the rarely beautiful pale turquoise-blue edging 

 on the edge of the suranal plate and anal legs, and in the pale bluish 

 tint on the ends of all the tubercles, and at the base of the middle 

 abdominal legs. 



The head is lemon-yellow as before, about one-half as thick as 

 the body, and is bluish on the region of the eyes. The prothoracic 

 segment is lemon-yellow, edged with pale blue, while the tubercles 

 are of a beautiful pale turquoise tint. The tubercles are still long 

 and slender, those of the thoracic and last two segments scarcely 

 larger than the others. 



In this genus the tubercles are remarkably long, with short, 

 small, pale radiating bristles, much shorter and slighter than in 

 Samia. 



The suranal plate also in stage V bears two low bosses without 

 bristles (only their rudiments), while in S. cecropia these tubercles 

 with their bristles are well developed; it also differs in the black 

 spots of the last stage. 



Those of the dorsal and subdorsal rows are pale whitish green at 

 base, passing toward the end into pale turquoise-blue. The infraspiracular row of tubercles are 

 ringed with black at the base. The black spots on the body are as in the previous stages. The 

 thoracic and abdominal legs are lemon-yellow, the latter pale bluish at base and on the planta. 

 The suranal plate and dorsal region of the ninth segment are lemon-yellow, the thickened much 

 swollen edge of the suranal plate is turquoise-blue, including the tubercles, and the edge of the 

 anal legs is of the same tint, the blue suddenly expanding on the lower side above the crotchets. 

 In this stage the body in general is turquoise bluish white, rather than pure white or slightly 

 yellowish white, as in stage III. 



August 20 one spun a cocoon, and the others stopped growing, perhaps partly on account 

 of the cooler climate than their parents had experienced, though the season of 1890 was a warm 

 one for Maine. 



By the larval characters this Chinese or eastern Asiatic genus is much more closely allied 

 to Samia than to Attacus, though the imago perhaps has more of the habit and general form 



Fig. 31. — Philosamia cynthia [walkeri] 

 male pupa. 



