THE FALL WEB-WORM. 35 
eggs for the first brood varies considerably, and the latter may be greatly 
retarded by inclement weather. Usually, however, not more than ten 
days are consumed in maturing the embryo within. The eggs of the 
summer brood seldom require more than one week to hatch. 
‘‘Without check the offspring of one female moth might in a single 
season (assuming one-half of her progeny to be female and barring all 
checks) number 125,000 caterpillars in early fall—enough to ruin the 
shade-trees of many a fine street. 
Fic. 18.—Hyphentria eunea: a,dark larva, seen from side; 5, light larva from above; ce, dark larva 
from above; d, pupa from below ; e, pupa from side; f, moth. 
The Larva (Fig. 18, a,b, and c).—‘ The caterpillars just born are pale 
yellow, with two rows of black marks along the body, a black head, and 
with quite sparse hairs. When full grown they generally appear pale 
yellowish or greenish, with a broad dusky stripe along the back and a 
yellow stripe along the sides; they are covered with whitish hairs, which 
spring from black and orange-yellow warts. The caterpillar is, however, 
very variable both as to depth of coloring and as to markings. Close 
observations have failed to show that different food produces changes 
in the coloration; in fact, nearly all the various color varieties may be 
found upon the same tree. The fall generation is, however, on the 
whole, darker with browner hairs than the spring generation. 
*¢ Assoon as the young caterpillars hatch they immediately go to work 
to spin a small silken web for themselves, which by their united efforts 
soon grows large enough to be noticed upon the trees. Under this pro- 
tecting shelter they feed in company, at first devouring only the green 
upper portions of the leaf and leaving the veins and lower skin unmo- 
lested. As they increase in size they enlarge their web by connecting 
it with the adjoining leaves and twigs; thus as they gradually work 
downwards their web becomes quite bulky, and, as it is filled with 
brown and skeletonized leaves and other discolored matter, as well as 
