422 MISC. PUBLICATION 657, U. S. DEPT. OF AGRICULTURE 
and some are well-known defoliators of forest and shade trees, appear- 
ing in outbreaks at irregular intervals. ‘Those species of most im- 
portance and those generally most common are discussed in some 
detail, including a brief description of the adults, but others which 
sometimes are more or less common, are reported more briefly. 
The moth of Brephos infans (Moeschler) has a wing expanse of 
about 11% inches. It is chocolate brown, the forewings marked with 
white and the hind wings with reddish orange. The full- grown larva 
is about 1 inch in length. The head, thoracic shield, and body are green 
or sometimes yellowish brown, and the body has two fine, ‘yellowish, 
longitudinal Imes on the dorsum and two similar subdorsal lines and 
a broad yellowish subspiracular stripe on each side. The prolegs on 
the third, fourth, and fifth abdominal segments are rudimentary. 
This species is distributed from Labrador to New York, and its food 
plants include gray birch, paper birch, and poplar. The moths 
emerge in Apr il and May, the larvae are active from May to July, 
they pupate in July, and hibernate in the pupal stage. 
The fall and spring cankerworms are serious pests of deciduous 
trees and have been known in the northeastern part of the United 
States for more than two centuries. Both species have much in com- 
mon. When abundant the larvae of either species, or sometimes both 
working together, defoliate the trees, leaving only the midribs and 
larger veins, thus causing enormous damage. They may be controlled 
by the measures given on pages 52-53. 
Porter and Alden (354) listed in 1924 the distinguishing character- 
istics of the fall and spring cankerworms as follows: 
Stage Fall cankerworm 
Bgoee ee Brownish gray, in form of a 
flowerpot, laid in a compact. 
single-layered mass in exposed 
locations, chiefly in the fall. 
Spring cankerworm 
Dull pearl, oval in shape, laid 
in loose elusters in protected 
places, almost exclusively in 
the spring. 
Larval. A pair of rudimentary prolegs No prolegs on the 5th abdominal 
on the 5th abdominal segment. segment. 
Rupa ssa Enclosed in a tough cocoon, No cocoon formed. 
with particles of earth woven 
in with the silk. 
Adult= = === Abdomen without spines______ Abdominal segments bearing 
double transverse rows of red- 
dish spines. 
The male moth of the fall cankerworm (A/sophila pometaria 
Harr.)) (fig. 88, D) is brownish gray with a wing expanse of 1 to 1% 
inches. The for ewlngs are rather glossy with purplish reflections and 
are crossed by two jagged whitish bands, sometimes both nearly ob- 
solete so that only the outer band is represented near the costa by a 
pale quadrate spot; the hind wings are grayish brown, each with a 
faint blackish discal dot. The female moth is wingless and of a shiny, 
dark, ash-gray color. ‘The abdomen is without spines in both sexes. 
The full-grown larva is about 1 inch long, and varies in color from a 
very hght green to a very dark, brownish green. On the back there 
is a median, longitudinal, darker stripe and sometimes suggestions of 
other faint lines. The head and anal segment also vary from pale 
green to almost black, and are sometimes mottled. There are three 
pairs of prolegs—a very small pair on the fifth abdominal segment, 
and larger ones on the sixth and anal segments, 
a 
