INSECT ENEMIES OF WESTERN FORESTS 67 
and very hairy, some of them being referred to as “woolly bears.” 
Most of the family are important as leaf feeders. 
The silver-spotted halisidota (Halisidota argentata Pack.) (fig. 
30) is a strikingly colored yellowish-brown moth with a wing spread 
of about 2 inches and a body covered with long yellow hairs. The 
forewings are reddish brown with numerous uniform silvery-white 
spots. The hind wings have a few brown marks near the outer 
FIGURE 30.—The silver-spotted halisidota; A, Full-grown caterpillar; B, eggs on needles ; 
C, adult male; D, adult female. All natural size. 
margin. The large moths emerge, fly, and mate during July and 
August. Pea-green eggs are deposited in clusters on the twigs and 
needles of the host trees. As many as 325 eggs have been laid by 
one moth. The caterpillars, which are densely clothed with long 
brownish to black hairs, congregate and feed heavily on the needles 
of young Douglas fir, balsam firs, pine, and spruce and are often 
