New Yorx AGRICULTURAL EXPERIMENT Station. 411 
that often occur in sufficient numbers to do serious injury. 
These are the spring canker worm (Paleacrita vernata Peck) and 
the fall canker worm (Anisopteryx pometaria Harr.) The former 
is the more common and injurious of the two. The life histories 
of the two species are very similar except that the eggs of the 
spring canker worm are laid in the spring and those of the fall 
canker worm in the fall. The eggs of both species hatch in the 
spring about the time the leaf buds are unfolding. 
Descriptions.— The eggs of the former species are placed some- 
what promiscuously in sheltered places on the twigs. They are 
small oval eggs and the shell has a brilliant pearly luster. The 
egos of the latter species are placed on end side by side in quite 
regular masses. They are somewhat cylindrical but smaller at the 
base and flattened at each end. | 
When first hatched the caterpillars of both species are very 
small and of a light green color. They devour the leaves rapidly. 
When disturbed they will drop, suspending themselves by silken 
threads. When mature they are about an inch long and vary in 
color from light green to darker shades. When ready to pupate 
they go into the ground, where the cocoon is spun and the chrysalis 
formed. Most of the spring canker worms remain in the ground 
until the first warm days of the following spring, but those of the 
other species come out of the ground in the fall. The adults of 
both species are moths. The females are wingless and the males 
winged. 
Treatment.— There are two principal methods of combating 
these insects. Tirst the females may be trapped while endeavor- 
ing to ascend the trunk of the tree. Numerous traps have been 
tested including bands of tin, cloth, waste wool, tarred paper and 
certain chemical preparations. Several patent metal devices for 
trapping the moths have been put upon the market recently. 
The most important point in connection with the use of traps in 
general is to put them on early in the season. It is usually advis- 
able to put the metal traps in place early in the fall to catch the 
