F-519524 
Figure 63.—Larvae and chrysalis of the butterfly, 
Polygonia interrogationis, the question-mark. 
Nymphalis vau-album (Denis & Schiffermiller), the Compton tortoiseshell, 
feeds principally on gray and paper birches, but also on poplar and willow in 
Canada and south to Pennsylvania in the Eastern States. Caterpillars have black 
heads, the body is reddish to blackish on the dorsum with dots of light green, and 
each segment bears a transverse row of branched spines. 
The mourningcloak butterfly, NV. antiopa (L.), is a widespread species, occur- 
ring throughout the subarctic regions of North America. The larvae, commonly 
known as spiny-elm caterpillars, feed on elm, willow, poplar, and hackberry, and 
are sometimes abundant locally, especially on shade and ornamental trees and along 
fence rows. Adults are black-bodied and have wingspreads of 60 to 80 mm. The 
upper wing surface is dark reddish-brown except for a broad, creamy-yellow border 
that contains a row of blue spots. Full-grown caterpillars (fig. 64) are black, with a 
scattering of white dots and a red dot on the dorsum of abdominal segments one to 
seven. The head is covered with tubercles: the body, with many large, branched 
spines. 
Courtesy Rocky Mt. For. & Range Exp. Stn. 
Figure 64.—Larva of the mourningcloak buttertly, 
Nymphalis antiopa. 
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