190 1. 



AMERICAN FORESTRY ASSOCIATION. 



WORK OF WESTERN PINE BARK BEETLE IN 



bark of Pinus ponderosa. specimen 



FROM M^LOUD RIVER NEAR MT. 

 SHASTA, CALIFORNIA. 



ample of a great destroyer of matured 

 spruce timber, which within the past half- 

 century has caused the death of billions of 

 feet of this valuable timber. 



There are a number of other examoles 

 of destructive enemies of the principal for- 

 est trees of the Rocky and Cascade moun- 

 tains and coast regions of the Northwest, 

 discovered by the writer during investiga- 

 tions there in the spring of 1S99. The 

 western pine destroyer* attacks and kills 

 the finest specimens of the Western Yel- 

 low Pine in California, Oregon, Wash- 

 ington and Idaho. The mountain pine 

 Dendroctonus f is destructive to the Moun- 

 tain or Silver Pine in eastern Washing- 

 ton, northern Idaho, and Montana, and 

 also infests the Sugar Pine of southern 

 Oregon. There is also a closely allied 

 species the pine-destroying beetle of the 

 Black Hills % which has been the cause 



* Dendroctonus brevicomis Lee. 



t Dendroctonus monticola Hopk. MS. 



% Dendroctonus ponderosa Hopk. MS. 



of serious trouble in the pine fori 

 western South Dakota and eastern V 

 ing. The Douglas spruce Dendrocton 

 is a common enemy of one of the tl 

 valuable timber trees of the Northvs 

 The fir tree destroyerf either kills, 

 causes a defective and decayed condition 

 of the heartwood, of the California and 

 grand fir trees from northern California to 

 British Columbia, and westward to Mon- 

 tana. The Douglas spruce bark bon 

 the western hemlock bark beetle? and 

 the western hemlock bark borer || infest 

 the living bark, and either kill the trees or 

 cause gum spot defects in the wood of the 

 Douglas Spruce and Western Hemlock in 

 Oregon and Washington. 



In addition to these examples of the 

 enemies of the living trees and timber 

 products, we may mention another ex- 

 ample of the depredations on oak and 

 hemlock tan bark by two or more species 

 of beetles, which convert into a fine pow- 

 der the " flesh " of the bark. These in- 

 sects are widely distributed through the 



SHOWS CHARACTER OF [NJ1 RY TO PINE BARK 

 BY THE DESTRUCTIVE PINE BARK Bl 



Dendroc onus pseudotsuga Hopk. MS. 

 t Scolytus ^ubscaber I ,ec. 

 %Aseiititm nit id 11 in Lee 

 I Hylesinus tsuga Hopk. MS. 



Melinophila arutnmondi Kirby. 



