LEPIDOPTRRA. 



177 



usually marked with yellow, and often with metallic blue or 

 green. 



There are about twenty-five species of swallow-tails in 

 America north of Mexico. The following well-known spe- 

 cies will serve as illustrations. 



The Black Swallow-tail, Papilio polyxenes (Pa-pil'i-o po- 

 lyx'e-nes). — The larva of this swallow-tail (Fig. 457) is well 



known to most 

 country children. 

 It is the green 

 worm, ringed with 

 black and spotted 

 with yellow, that 

 eats the leaves of 

 caraway in the 

 back yards of coun- 

 try houses. It feeds 

 also on parsnip and 

 other umbelliferous plants. These 

 caterpillars always fascinated us in 

 our childhood ; we have spent many 

 idle moments in poking them with 

 straws to see them rear upward and 

 project their yellow horns, which gave 

 off a sickening odor. When ready to 

 transform the caterpillar crawls away 

 to a fence or the side of the house 

 and changes to an angular pupa, sus- 

 pended by the tail and by a little 

 silken girth around the middle. 



In the adult the wings are black, 

 crossed with two rows of yellow spots, 

 and with marginal lunules of the same 

 color. The two rows of spots are 

 much more distinct in the male than in the female, the in- 

 ner row on the hind wing forming a continuous band crossed 



Fig. 457. — Papilio polyxenes, 

 larva. 



