STATE AGRICULTURAL SOCIETY. 
425 
At length driven to migrate elsewhere or perish from starvation, 
they leave the tree, one following the track of another, travel¬ 
ing in the direction in which they discern or suppose they dis¬ 
cern other trees to be standing. If it is pasture land in which 
they are traveling, every stalk of clover, every dandelion leaf 
and other weed which they come to is examined to its summit 
in search of something which is edible. I once saw a heap of 
dry brush, every limb of which was overspread with the threads 
of a swarm which was thus emigrating, so little ability have 
they for discerning where food can be found. Their track may 
commonly be traced through the grass by the threads which they 
spin, to a distance of one or two rods, it gradually becoming 
less distinct as one worm after another has strayed away from it, 
impatient to find something wherewith to appease his hunger. 
Being 'already famished before leaving the tree it is probable 
that most of them perish before finding anything nutritious on 
which to feed. The cherry puts forth a scanty crop of new 
leaves after the worms have left it: and I have known trees to 
be totally defoliated three and four years in succession by these 
caterpillars, without being killed. But when thus assailed they 
grow but little, if any, and acquire a decrepit appearance from 
which they do not recover for several years. 
The LARVA! when they first come from the eggs are 0.08 long, slightly taper¬ 
ing, of a black color, the under side and legs pallid, and they are slightly 
clothed with soft gray hairs. After they commence feeding they show a pale 
ring at each of the joints, and a faint pale stripe lengthwise along the back upon 
each side of its middle, and another low down upon each side. The head is 
deep black, and some deep black dots may be discovered upon the body, from 
which the hairs arise. When they are a few days old and before the first 
moulting, they have increased to double their original size, and show some 
ash-gray or whitish lines more or less distincly, running lengthwise upon the 
back and sides. 
A worm which I confined by itself cast its skin the first time on the 6th of 
May, again on the 12th, a third time on the 15th, a fourth time on the 19th, and a 
fifth time on the 28th, being now an inch long. I think it would not have 
moulted again, but as it escaped from its confinement, a week after the last 
date, I cannot be certain upon this point. 
Sifter the first moult this worm was 0.20 long, of a dark gray color with 
two ashy-white lines along the back and two along each side, the space above 
the upper lateral line having a large blackish spot on each segment. The 
hind edges of the segments and the under side of the body was also pale ask 
[Assembly, No. 217.] 28 
