22 MISC. PUBLICATION 290, U. S. DEPARTMENT OF AGRICULTURE 



beetles and defoliating insects. Among the first group are the west- 

 ern pine beetle, the mountain pine beetle, the Black Hills beetle, the 

 Engelmann spruce beetle, the southern pine beetle, and the eastern 

 spruce beetle. The gypsy moth, the spruce bud worm, and the larch 

 sawfly are serious defoliating insects. Beetle outbreaks frequently 

 follow forest fires when, because of damage by burning, the trees' 

 powers of resistance are low. 



Where insect attacks reach epidemic proportions on the national 

 forests, control measures are undertaken in cooperation with the 

 Bureau of Entomology and Plant Quarantine. Experimental work 

 in insect control also is carried on in cooperation with this bureau. 



TEEE DISEASES 



Tremendous losses of timber and young growth are caused by 

 tree diseases, such as the white-pine blister rust. Some of the most 

 destructive tree diseases have been imported from other countries 

 on planting stock. Efforts are now being made to combat those 

 already imported and to prevent, by quarantine, the importation of 

 new diseases. 



In its control work against tree diseases in the national forests, 

 the Forest Service is aided by the Division of Forest Pathology, 

 Bureau of Plant Industry, and the Division of Plant Disease Con- 

 trol, Bureau of Entomology and Plant Quarantine, Department of 

 Agriculture. The Division of Forest Pathology maintains patholo- 

 gists in several of the regional offices and forest experiment stations 

 of the Forest Service. 



STATE AND PRIVATE COOPERATION 



Paralleling in importance the administration of the national 

 forests is the work being done by the Forest Service in cooperation 

 with State and private forest-land owners toward better manage- 

 ment of American forests as a whole. The importance and extent 

 of such operations is clearly seen in the fact that there are in the 

 United States more than 426.000,000 acres of land under State and 

 private ownership, chiefly valuable for the growing of timber. It is 

 apparent that the manner of utilization of these areas profoundly 

 affects the social and economic conditions of a large percentage of 

 American citizens and communities. The Forest Service, through its 

 branch of State and private forestry cooperation, is endeavoring to 

 bring about on these lands the sort of utilization that will have the 

 most favorable effect on the public welfare. 



BETTER MANAGEMENT OF PRIVATE FORESTS 



Management under the principle of sustained yield, which en- 

 ables forest lands to produce tree crops indefintely, is necessary if 

 the social and economic values of our forest lands are to be perma- 

 nent. That this principle is workable has been proved in the man- 

 agement of the national forests. Extending it to all American for- 

 ests and woodlands is the logical goal. In the interests of American 

 democracy, of which the free and independent ownership of land is 

 so much a part, the extension of management designed to perpetuate 

 the means by which such ownership can be maintained is a vital 

 necessity. 



