424 MISC. PUBLICATION 657, U. S. DEPT. OF AGRICULTURE 
plants, but elm and apple seem to be most preferred. The moths 
emerge in November and December, usually not until there has been 
some freezing weather. Occasionally the emergence of a few moths 
is delayed until spring. The eggs are usually deposited on the smaller 
branches and twigs in clusters averaging about 100 eggs. The winter 
is passed in the egg stage and hatching takes place early in May. The 
young larvae seem to prefer the newly formed leaves on the tips of the 
branches, skeletonizing them, but in later instars they devour all but the 
midribs and larger veins of the leaves. The larval stage extends over 
a period of 4 to 5 weeks; the full-grown larvae entering the soil for 
pupation during the first or second week in June. 
The male moth of the spring cankerworm (Paleacrita vernata 
(Peck) ) (fig. 89) has a wing expanse of 7% to 114 inches. The first 
seven joints of the abdomen each bear two transverse, dorsal rows of 
stiff, reddish spines, pointed posteriorly. The forewings are silky 
with brownish-gray scales loosely attached. They are crossed by 
three jagged, dark lines, sometimes nearly obsolete except on the 
median and submedian veins and on the costa, where they are always 
distinct. A pale subterminal band is somewhat similar to the outer- 
most band in Alsophila pometaria. The hind wings are pale, ashy 
gray, with a dusky discal dot. The female moth is wingless, gen- 
erally whitish and brown or black, but not uniform in color. The two 
rows of spines on the back of the first seven joints are more prominent 
than in the male, and often give the back a reddish aspect. 
The full-grown larva is 34 to 1 inch in length, and varies from red- 
dish to yellowish brown or yellowish green and sometimes blackish. 
The head is dirty white, mottled with brown, the body lines are irregu- 
lar, numerous, considerably broken, distinct in some individuals and 
to some extent missing in others. There are two pairs of prolegs, 
which are present on the sixth and anal segments. 
This species is found from Nova Scotia south to North Carolina, 
southwesterly to eastern Texas, westerly to Colorado, and north to 
Manitoba. It has also been found in California. Apple and elm 
seem to be the preferred food plants, but several of the oaks, cherries, 
hickories, maples, and others are included in the list of hosts. The 
moths issue in the spring soon after the frost is out of the ground. 
The eggs are deposited in crevices in the bark in masses ranging from 
a few eggs to 100 or more. The habits of the moths, the date of hatch- 
ing of the eggs, and the habits of the larvae are very similar to those 
of the fall cankerworm (Alsophila pometaria). The larvae become 
full grown and enter the ground for pupation at about the same time 
as do the fall species. No cocoon is formed, but pupation takes place 
in a cell and the winter is passed there. 
The full-grown larva of Synchlora aerata (F.) is brownish, about 
7% inch in length, with curved lateral appendages on the back. Its 
food plants include apple and willow. There may be two generations 
in some localities. ‘The larvae may be found from June to September, 
the winter is passed as pupae in the ground, and the moths emerge late 
in May and June and in August. The full-grown larva of S. rub- 
rifrontaria Pack., is similar in appearance to the preceding species, 
except that it is green with a reddish tinge, especially on the lateral 
appendages. Its favored food plant is sweetfern. ‘The larvae are 
