386 MISC. PUBLICATION 657, U. S. DEPT. OF AGRICULTURE 
to 400 in a single layer on the under sides of the leaves. The larvae 
are gregarious “until nearly full grown and may be found from June 
until October, as the dur ation of the feeding period varies consider- 
ably. The winter is passed in the pupal stage in a gray, hairy cocoon 
constructed of silk and hairs from the body of the larva. 
The spotted tussock moth (//alisidota maculata (Harr. )) is pale 
yellow, and has a wing expanse of about 124 inches. The forewings are 
marked with brown spots, the outer one of which forms an irregular 
subterminal band. The full-grown larva is about 114 inches in length 
with a large and shiny black head. The body is dull black above, 
thickly clothed with tufts of black and bright yellow to whitish hairs, 
with a row of short tufts down the middle of the back, mostly black. 
FIGURE 75.—A, Larva of the hickory tussock moth (Halisidota curyae); B, larva 
of the pale tussock moth (H. tessellaris). (Courtesy Conn. Agr. Expt. cou 
The hairs on the sides of the second to sixth abdominal segments, in- 
clusive, are yellow, but others are black, the tufts on the second and 
third thoracic and the eighth abdominal segments are longer than 
those on the others and have some yellowish or white hairs inter mixed 
with black; those of the thoracic segments overhang the head. Prior 
to the last instar the larva has been much lighter in color. 
According to Holland (229), the species in 1903 ranged from the 
northern portions of the Atlantic coast region westward to California. 
It is sometimes very common in the northern portions of the North- 
astern States, but has not been recorded as a serious defoliator. The 
larvae are solitary in habit and feed on alder, apple, aspen, birch, 
boxelder, wild black cherry, maple, oak, and willow. The moths 
emerge from late in May to July, larvae are found from July to Octo- 
ber, and the winter is passed in the pupal stage in a hairy cocoon. 
The pale tussock moth (Halisidota tessellarés (A. & S.)) has a 
wing expanse of 114 to 2 inches. The head and body are pale buff 
yellow, the collar and inner margins of the shoulder lappets tinged with 
