INSECT ENEMIES OF WESTERN FORESTS 



239 



quickly extinguish any fire left on the tree or starting on the 

 ground. 



The Peeling Method 



The peeling method can be used in the control of those bark 

 beetles that, in the immature stages, work between the bark and 

 the wood and die of exposure when the bark is removed. It is 

 especially applicable to moderately thick-barked trees that are 

 easily peeled. It has been used extensively in the control of the 

 Black Hills beetle in ponderosa pine of the Rocky Mountain region 

 and in the control of the mountain pine beetle in western white 

 pine. There is no immediate fire risk, and it is cheaper than the 

 burning method for the treatment of isolated trees less than 30 

 inches in diameter. If the bark tends to adhere to the wood, how- 

 ever, peeling is a very slow, tedious process and in the spring will 

 not destroy overwintering adults, new adults, or pupae in the last 

 stages of transformation. It is more expensive than the burning 

 method for the treatment of trees in groups. Moreover, it leaves 

 a mass of slash and crisscrossed logs in the woods, seriously 

 increasing the fire hazard. 



In carrying out this method, the infested trees are felled across 

 logs or other felled trees to hold them off the ground, and then 

 all the infested bark is peeled with an ax or barking spud and 

 allowed to drop to the ground, where ants, rodents, and exposure 

 dispose of the immature bark beetles (fig. 111). In some rare 



Figure 111. — Using spuds to peel western white pines infested with bark 



beetles. 



