U. S. DEPARTMENT OF AGRICULTURE, 



BUREAU OF ENTOMOLOGY— BULLETIN No. 83, Part I. 



L. O. HOWARD. Entomologist and Chief of Bureau. 



PRACTICAL INFORMATION ON THE SCOLYTID BEETLES 

 OF NORTH AMERICAN FORESTS. 



I: BARKBEETLES OF THE GENUS 

 DENDROCTOOTS. 



A. D. HOPKINS, Ph. D., 



In Charge of Forest Insect Investigations. 



Issued October 11, 1909. 



WASHINGTON: 



GOVERNMENT PRINTING OFFICE. 



1909. 



