INSECT ENEMIES OF WESTERN FORESTS 101 
eter and for those that, owing to drought or other causes, are in 
a weakened condition. It is most frequently found attacking mature, 
slow-growing trees on the lower fringe of pine growth and trees 
FicurE 49.—Typical winding egg galleries of western pine beetle marking the surface 
of the wood. 
exposed on rocky ridges and dry southern slopes. This insect and the 
pattern of its galleries can scarcely be distinguished from those of 
the western pine beetle, but as methods of control are also the same, 
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