LIFE HISTORY OF LODGEPOLE PINE IN ROCKY MOUNTAINS. 21 



Hopk.) . A few trees apparently killed by its attack have been found 

 on the Medicine Bow and Bighorn National Forests in Wyoming, 

 and on the Arapaho Forest in Colorado. The attack was confined 

 mainly to the bases of the trees and to unhealthy individuals. The 

 Oregon tomicus was also found, but it is probable that the dendroc- 

 tonus made the first attack. A weevil similar to the eastern white 

 pine weevil {Pissodes strobi) has also been found on the Arapaho 

 National Forest. This insect destroys the terminal shoot, resulting 

 in crooked and forked trees. 



FUNGI AND MISTLETOE. 



Lodgepole has, on the whole, suffered comparatively little damage 

 from fungi. This is due chiefly to the fay climate of its range and 

 to the fires which have renewed the stands from time to time, thus 

 preventing any extensive development of the fungous diseases. Often 

 badly fire-scarred trees may remain sound as long as 40 or 50 years, 

 except for a small amount of blue stain along the edges of the scar. 

 One of the two most common diseases of lodgepole is that caused by 

 the ring scale fungus {Trametes pini), often called by woodsmen 

 " white rot " or " red rot." Another common disease is caused by the 

 fungus Polyporus schweinitzii. The ring scale fungus attacks chiefly 

 the older trees, which it may enter at almost any point where a dead 

 limb or wound affords an opening. From the point of infection it 

 sometimes extends throughout the trunk. The wood at first turns a 

 dark reddish brown, the trees at this stage being known to lumber- 

 men as " red rot " or " red heart " timber. Later the color of the 

 wood becomes lighter and small white spots and strands appear, 

 increasing in size and number until the entire heartwood is filled with 

 small holes lined with the thin, white cellulose of the wood which has 

 not been used as food by the fungus. The wood never rots entirely 

 away, but eventually becomes a mass of soft, spongy tissue. 



The fungus Poly poms schweinitzii usually causes a heart rot at 

 the butt. Since it is confined to the first or second logs it is less 

 destructive than the ring scale fungus. When the roots are infected 

 the tree may fall ; in other cases it may break off close to the ground 

 before the rot has had time to spread far into the trunk. The affected 

 wood turns a light yellow and gradually dries out so that numerous 

 fissures appear. 



In overmature lodgepole stands from 7 to 10 per cent, or on limited 

 areas even 15 to 20 per cent, of the timber may be affected by one or 

 both of these fungi to an extent rendering it unmerchantable. It is 

 seldom, however, that an entire tree is made worthless by rot, and one 

 or more sound logs or ties can usually be obtained. The blue stain, 

 which may appear almost immediately in the sapwood of fire-killed 

 or insect-killed trees, does not render them unfit for use. 



