CONTENTS" 



Page 



The locust borer ( Cyllene robinix Forst.) A. D. Hopkins. . 



Object of paper 



Economic importance of the insect 



Investigations 



Character of the insect and its work 2 



Extent of damage or loss 3 



Possibilities of preventing losses 3 



Historical references 3 



Observations by the writer, 1890-1905 7 



Observations by members of the Forest Service 9 



Recent observations by the writer 9 



Suggestions for controlling the insect and preventing losses 11 



Suggestions for propagating borer-resistant trees ; 13 



Publications relating to the locust borer 15 



The western pine-destroying barkbeetle (Dendroctonus brevicomis Lee), 



J. L. Webb.. 17 



Introduction 17 



Death of the pine caused by the western pine-destroying barkbeetle 18 



Character of the insect and its work 18 



Distribution 19 



Extent of damage and losses 19 



Possibilities of preventing losses 20 



Early history of the species 20 



Observations by Hopkins, 1899-1904 21 



Observations by H. E. Burke, 1904 23 



Observations by the writer, 1905 23 



Life history and habits of the insect. 23 



Natural enemies 27 



Methods of combating the insect 27 



Summary 29 



Publications relating to the western pine-destroying barkbeetle 30 



Additional data on the locust borer ( Cyllene robinix Forst.).. J.. D. Hopkins. . 31 



Seasonal history 31 



Habits of larvae and adults 33 



Economic features 34 



Natural enemies 35 



Methods of control :>(> 



The southern pine sawyer ( Monohammus titillator Fab.) J. L. Webb . . 41 



Introduction 41 



History 42 



Distribution 43 



Host plants 43 



Condition of trees attacked 43 



I njury to pine forests by storms 43 



a The five papers constituting this bulletin were issued in separate form on June 13 

 and August 18, 1906; March 5, 1907; and November 10 and December 4, L909, respec- 

 tively. 



