PREFACE. 



The report submitted herewith, entitled The " Bluing" and the 

 "Red Rot" of the Western Yellow Pine, with Special Reference to the 

 Black Hills Forest Reserve, covers in part an investigation under- 

 taken by the Bureau of Plant Industry in cooperation with the Bureau 

 of Forestry in the broad field of the diseases of forest trees and the 

 means of controlling them, as well as the causes of and methods of 

 preventing the decay of all kinds of timber, especially that valuable 

 for construction purposes. At the present time an immense quantity 

 of dead and dying timber of the bull pine is standing in the Black 

 Hills Forest Reserve, South Dakota. The amount has been variously 

 estimated, but will probably approach 600,000,000 feet. The death of 

 the trees was caused by the pine-destroying beetle of the Black Hills, 

 as shown by investigations conducted by the Division of Entomology 

 of the United States Department of Agriculture. a Following attack 

 by the beetles the wood of the tree is invaded by various fungi, one of 

 which causes the blue coloration of the wood. Dr. von Schrenk has 

 demonstrated, however, that the fungus which causes the bluing does 

 not injure the strength of the wood. 



The rapid decay or "red rot" of the timber is caused by another 

 fungus, and its ravages can be forestalled by a proper use of the 

 wood. A series of recommendations is made, which, if followed, will 

 result in the saving of a very large part of the dead wood. 



ALBERT F. WOODS, 

 Pathologist and Physiologist. 



OFFICE OF THE PATHOLOGIST AND PHYSIOLOGIST, 



Washington, D. C., December <23 , 190%. 



Bull. 32, n. s., Division of Entomology, U. S. Dept. of Agriculture, 1902. 



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