260 LEPJDOPTERA. 



with a spot of dark yellow at their base ; and on the fourth 

 segment are four spines, as there are on all the others, except- 

 ing the terminal, which has two pairs, one posterior to the 

 other. The spines are yellow, with blackish branches, except- 

 ing the terminal pair which is black ; and there is a row of 

 reddish ones on each side. The under surface is yellowish grey, 

 darker on the anterior segments, with a central line of blackish 

 and many small, black dots." The chrysalis state lasts from 

 twelve to fourteen days. It is ash brown, with the head deeply 

 notched, and eight silvery spots on the back. Grapta c-argen- 

 teum Kirby (Fig. 188, GL Progne Harris) is a small species 

 with a silvery L in the middle of the under side of the hind 

 wings. It is our most common species northward. It appears 

 the last of summer. The larva lives on the hop and elm. 



Grapta comma Double- 

 day is more common 

 southward. It is known 

 by having a silvery 

 comma in the middle 

 of the hinder wings. 

 The caterpillar lives on 

 the hop and elm. Mr. 

 W. H. Edwards has 

 Fig. 188. found the larvae on the 



broad-leaved nettle. He says "my attention was first attracted 

 by observing certain leaves drooping, and more or less eaten. 

 On the under side of these I usually found the caterpillar 

 inactive, and never more than one upon the same plant. The 

 half-grown larvae were black, with a 3 r ellowish stripe along the 

 side from the third segment to the tail, and with yellow stripes 

 across the back, and spots of the same color at the base of 

 the dorsal spines, which were yellow, tipped with black. The 

 mature larvae were white, mottled or striped with grey or 

 ashen, and with red spiracles." 



The chrysalis is brownish gray or white, variegated with 

 pale brown, and ornamented with gold on the tubercles. The 

 fly appears in May, July, August and September. In the colder 

 and mountainous portions of New England and New York, 

 these species are replaced by the Ch-apta Faunus of Edwards, 



