LETTER OF TRANSMITTAL. 
U. S. Department of Agriculture, 
Bureau of Entomology, 
Washington, D. C, March 31, 1909. 
Sir: I have the honor to transmit herewith manuscript of the 
first part of a proposed bulletin of this bureau, to be entitled " Practical 
Information on the Scolytid Beetles of North American Forests." 
The present part is entitled "Barkbeetles of the Genus Dendroc- 
tonus," and deals with the more practical results of extensive inves- 
tigations by Doctor Hopkins between 1891 and 1908, and of those 
conducted by him and under his immediate supervision by field 
and office assistants of this Bureau, Messrs. W. F. Fiske, H. E. Burke, 
and J. L. Webb. It relates to the most destructive enemies of the 
coniferous forests of North America, gives practical methods for 
their control, and serves as a supplement to Technical Series No. 17, 
Part I, the two publications together making a very complete tech- 
nical and popular monograph of the genus Dendroctonus, the major 
part of which is based on original research. It is believed that these 
contributions will mark an important era in the history of forest 
entomology in America, and should be of special value to the sys- 
tematic and economic entomologist and to students of forest ento- 
mology. This part should be of exceptional interest and value to 
practical foresters in the management of National and State forests, 
as well as to private owners of forests. The illustrations are mainly 
reproduced from Technical Series No. 17, Part I. 
I recommend the publication of this manuscript as Bulletin No. 
83, Part I, of the Bureau of Entomology. 
Respect fu ily, 
L. O. Howard, 
Entomologist and Chief of Bureau. 
Hon. James Wilson, 
Secretary of Agriculture. 
