INSECT ENEMIES OP WESTERN FORESTS 



187 



Figure 89. — Felling bark-beetle-int'ested ponderosa pines is the first step in their treatment. 



In this method the infested trees are first felled (fig. 89), either 

 up or down hill but away from new growth or heavy patches of 

 brush — never across the slope of the hill, if this can be avoided, 

 since a broad flame is more difficult to control than a narrow one. 

 Then the bark is peeled from the top half of the fallen trunk for 

 as far as the infestation extends, piled along the sides, and set on 



