COURTESY CONN. AGR. EXPT. STA. 
FIGURE 113.—Larva of the pale 
moth, Halisidota tessellaris. 
The sycamore tussock moth, Halisidota harrisii (Walsh), feeds 
on sycamore and London plane trees, and it probably occurs 
wherever sycamore grows in this country. Adults are indis- 
tinguishable from those of the pale tussock moth, and the larvae 
of the two species differ only in color. Those of this species have 
yellowish bodies clothed in whitish to yellow hairs and their long 
hair pencils are orange-colored. Infestations are often heavy on 
shade and ornamental sycamore in the Northeast. 
The fall webworm, Hyphantria cunea (Drury), occurs through- 
out the United States and southern Canada. Its hosts include 
more than 100 species of forest and shade trees. The adult has a 
wingspread of 30 to 42 mm., and the bases of the front legs are 
orange or bright red. In the southern part of its range, the moth 
is white, usually with dark spots on the wings. In the North, 
particularly in eastern Canada, it is nearly always pure white 
and is often referred to as H. textor Harris. Full-grown larvae 
are usually pale yellowish or greenish, with a broad dusky stripe 
down the back and a yellowish stripe down each side. They are 
about 25 mm. long. The larvae of the textor form are dark. Their 
bodies are covered with long silky, gray hairs arising in tufts 
from orange-yellow or black tubercles. 
Adults appear mostly from May to July and deposit their eggs 
in hair-covered masses of several hundred eggs each, usually on 
the undersides of leaves. Newly-hatched larvae immediately begin 
to spin a silken web over the foliage on which they feed; and, 
as they grow, they enlarge the web to enclose more and more 
foliage (fig. 114). On heavily infested trees several branches may 
be enclosed in webs. Small trees are often enclosed entirely. The 
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