LEPIDOPTERA 



95 



may easily be recognized, as they are the largest of our but- 

 terflies, and have tail-like projections on the hind wings. 

 The larvae have scent organs on the first thoracic seg- 

 ment. These are two orange-red, horn-shaped, extrusible 

 structures which are 

 thrust out when the 

 insect is disturbed. They 

 give off a strong and un- 

 usual, but not exactly 

 unpleasant, odor. Swal- 

 low-tail pupae or chrys- 

 alids are supported by 

 the button of silk at the 

 tail end and by the gir- 

 dle around the middle. 

 They are angular and 

 have two short projec- 

 tions at the front end 

 of the body. Swallow- 

 tail larvae are rarely nu- 

 merous enough to be in- 

 jurious. 



The species common 

 over the greater part of 

 the eastern United States 

 are few in number. 

 The Black Swallow-tail 

 is probably the most 

 common and is the 



smallest. Its larvae feed on celery, rue, parsley and sim- 

 ilar plants. The ground color is black and on the hind 

 wings are numerous yellow spots and some shading with 

 light metallic blue. The Tiger Swallow-tail or Turnus is 



FIG. 69. Larvae of the Rosy Maple- 

 moth. Reduced. 



