INSECT ENEMIES OF EASTERN FORESTS 369 
and two on the first abdominal segment, the first two with black 
centers. ‘There are six small spots on abdominal segments 2 to 7, 
and four on the eighth (fig. 70, C). Its principal food plants are 
spicebush (Benzo) and sassatras, and although sometimes very com- 
mon it probably never is a serious pest. The life history and habits 
are similar to those of P. turnus. 
Famity NYMPHALIDAE 
The Nymphalidae is the largest family of butterflies, most of its 
species being of medium to large size and of a great variety of striking 
forms. ‘They may be distinguished from all other butterflies by their 
small or rudimentary forelegs, which are folded on the breast and 
cannot be used in walking. Many of our most common species are 
included in this family. The larvae are spiny or have fleshy warts 
covered with hair. The head is usually more or less bilobed, the tips 
of the lobes often supporting branched spines. The chrysalids are 
naked and are suspended by the cremaster. Holland (228) described 
the stages of many species of the family Nymphalides. 
Although many species of this family are at times very common, few 
ever become abundant enough to warrant the practice of artificial 
control measures. A few species are discussed briefly. 
Polygonia interrogations (¥.), the question-sign, as a full-grown 
larva is about 114 inches long. The head is dark red, the body 
brownish, mottled with yellow, and each segment bears a transverse 
row of light-colored branched spines, some of which may be tipped 
with black (fig. 70, D). This species is distributed throughout the 
United States east of the Rocky Mountains, and in Canada and Nova 
Scotia. The larvae are often very common on elm, particularly on 
seedling and sprout growth along roadsides, feeding on the tender 
leaves of the terminal twigs. They also feed on hackberry and hop. 
In most of its range there are two generations, the adults hibernate 
during the winter, and the larvae may be found from May to 
September. 
The full-grown larva of Polygonia comma (Harr.), the hop mer- 
chant or comma butterfly, is about 114 inches long. The head is gray- 
ish in front and black on the sides, the body is yellowish white, and 
each segment has a transverse row of light-colored, branched spines, 
tipped with black. It ranges from the Carolinas to Texas and north 
into Canada. The larvae feed on elm, nettle, and hop, and are some- 
times abundant on the latter. The life history and habits are very 
similar to those of the preceding species. . 
The full-grown larva of Vymphalis j-album (B. & L.) is about 
114 inches long. The head is black, the body reddish to blackish 
on top dotted with light green, each segment with a transverse row 
of branched spines, those below the spiracles usually of a hght color 
and those above black. This species has been reported from Penn- 
sylvania and northward from Labrador to Alaska. ‘The larvae feed 
on gray birch and paper birch, and are also reported on poplar and 
willow. Apparently it is never important as a pest. The adults 
hibernate, and the larvae may be found from May to July. 
The mourning cloak butterfly (Vymphalis antiopa (.)) is dark 
brownish purple with the outer edge of the wings banded with 
