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yellow pine (Pinus ponderosd) in northern California, southern and 

 eastern Oregon, northeastern Washington, and western Idaho. A large 

 amount of some of the finest timber in all of these localities had died 

 within the past seven or eight years, evidently as a direct result of 

 attacks by this bark beetle. It was also found to attack and prevent 

 the recovery of trees injured by defoliating insects and other causes. 

 Its habits and the character of its galleries appear to be identical with 

 those of Dendroctomis frontalis, which is noted for its destruction of 

 vast quantities of pine and spruce timber in West Virginia and adjoin- 

 ing States between 1890 and 1893. It is killing the Western yellow 

 pine, just as D. frontalis commenced to kill the Eastern yellow pine 

 {Pinus echinata) before it spread to all the other pines and spruce. 

 Therefore, just as D. frontalis has proven to be the most destructive 

 enemy of Eastern conifers, the Western representative of this species 

 will doubtless prove to be, under similarly favorable conditions, equally 

 as destructive to the Western forests in which the conifers predominate. 



Among the most important features observed regarding the habits of 

 this beetle was the fact that it is attracted to trees girdled by settlers 

 and farmers in the process of clearing land, and that in the bark of 

 such trees it breeds and multiplies in sufficient numbers to enable it to 

 attack and kill the timber in adjoining healthy forests. Indeed, my 

 observation leads me to conclude that a considerable number of girdled 

 pine trees may easily form a nucleus for a destructive invasion by it. 



A Dendroctonus allied to the one just mentioned, but evidently unde- 

 scribed, was found to be a special and dangerous enemy of the sugar 

 pine (Pinus lambertiaria) and the mountain white pine (Pinus monti- 

 cola), especially of the latter. It was frequently met with in the 

 vicinity of Grants Pass, Oreg. , in sugar pine, and was found abundant 

 in the bark of dying and dead standing and felled white-pine trees in 

 the vicinity of Sand Point and Kootenai, Idaho, where a large amount 

 of timber had died, evidently as a result of its attack. This is the 

 same beetle as the one sent to the Division of Entomology by Mr. 

 Ayers from Columbia Falls, Mont., and subsequently sent to me, with 

 other Dendroctonus material, for study. It is undoubtedly capable of 

 attacking and killing great quantities of white and sugar pine, but may 

 possibly be prevented from doing so in the future, in all regions where 

 extensive timber cutting is carried on, by its being attracted to the 

 stumps, logs, and tops of trees felled for lumber and fuel. 



Another species, at present recognized as Dendroctonus terebrans, 

 was commonly met with in the bark of living, dying, and dead stand- 

 ing trees and the stumps of recently felled Pinus ponderosa, P. lam- 

 bertiana, P. monticola, P. murrayana, P. contorta, and P. radiata, in 

 all of the localities where these species of pine grow. It was found 

 to be quite a common enemy of the Monterey pine on the university 

 campus at Berkeley, Cal. , and I was informed by Professor Davy that 



