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 

 fore wings are reddish brown with numerous uniform silvery- white 

 spots. The hind wings have a few brown marks near the outer 



Figure oU. — The silvei-spotled Imlisidula ; .1, 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 



