LEPIDOPTERA 



255 



thoracic segments are larger than the others, and are coral-red. The 

 other dorsal tubercles are yellow, excepting those of the first thoracic and 

 last abdominal segments, which with the lateral tubercles are blue; all 

 are armed with black bristles. The cocoon is represented by Figure 446. 

 The ailanthus-worm, Philosamia walkeri. — This is an Asiatic species 

 which has been introduced into this country. It has become a pest in 

 the vicinity of New York City, where it infests the Ailanthus shade-trees. 

 The moth differs from all our native species of this family in having rows 

 of tufts of white hairs on the abdomen. Its cocoon resembles that of the 

 promethea-moth. The specific identity of this species is in doubt. 



Family Bombycid^e 



The Silk-worm 



The family Bombycidse is not represented in our fauna; but a single 

 species, the silk-worm, is frequently bred in this country, and is usually 

 present in collections of Lepidoptera. 



The silk-worm, Bombyx 

 won. — The moth (Fig. 447) 

 is of a cream-color with 

 two or three more or less 

 distinct brownish lines 

 across the fore wings and 

 sometimes a faint double 

 bar at the end of the discal 

 cell. The head is small; 

 the antennas are pectinated 

 broadly in both sexes; and 

 the ocelli, palpi, and 

 maxillae are wanting. A 

 striking feature of the 

 venation of the wings (Fig. 

 448) is the obvious pres- 

 ence of the base of vein Ri 

 in the hind wings. 



2dA 



Fig. 448. — Wings of Bombyx mori. Fig. 447. — Bombyx mori. 



The usual food of the silk-worms is the leaf of the mulberry. Our 



