SPAN-WOKMS. 197 
THE SPRING CANKER-WORM. 
(Paleacrita vernata Pack). 
This canker-worm appears in its winged form early in 
spring, although specimens are also sometimes found late in 
autumn. The females, which are wingless, ascend the trunks 
of trees to deposit their eggs. These are of a very delicate 
texture and of a pearly lustre; they are deposited in masses 
of several hundreds, without regularity, and are usually well 
hidden in the crevices of the bark. The voung caterpillars 
are of a dark olive-green or brown color, with black shining. 
heads, and a horny cervical-plate of the samecolor. When full 
grown they are about an inch long, of very variable colors. 
The head is usually mottled and spotted, and has two pale 
transverse lines in front; the body is longitudinally striped 
with many narrow pale lines; along the sides it becomes 
deeper in color, and down the middle of the back are some 
a : 
Fig. 195.—Paleacrita vernata Pack. After Riley. 
dark spots. When mature these caterpillars descend to the 
ground in which they penetrate to some depth and where 
they make a rather fragile cocoon. 
The female of this canker-worm, as well as the male, has 
upon the posterior margin of each segment two transverse 
rows of stiff reddish spines. The female has a long and 
retractable ovipositor, which is not found in _ the Fall 
Canker-worm. The male has pale ash-colored or brownish- 
gray silky fore-wings, which are so thin as to be almost 
transparent. A broken whitish band crosses the wing near 
the outer margin and three interrupted brownish lines are 
