U. S. D. A., 15. K. r.nl. r.s. I'iiit V. F. 1. I., December 4, I'JU'J. 



SUMK INSECTS IMUKIOUS TO FOIIESTS. 



INSECT DEPREDATIONS IN NORTH AMERICAN FORESTS 

 AND PRACTICAL METHODS OF PREVENTION AND 

 CONTROL. 



r.y A. 1). IIoi-KiNs. I'll. I)., 

 In Cliiirf/c (if I'orcMl In.sccI Ini < Kfii/dtiouft. 



INTRODUCTION. 



It is' the purpose of this [)ait of the bulletin to ^ffive a summary of 

 facts, conclusions, and estimates relating to the forest-insect problem 

 as applied to North American conditions and to call attention to its 

 importance in the future management of private, state, and national 

 forests. 



Tlie matter is presented in as brief and concise a form as jDOssible, 

 in order that the informati{m may be readily available to the general 

 reader, as Avell as to the forester and student, and references are 

 made to publications in which more detailed accounts may be found. 



The statements and conclusions relating to the insects and their 

 work and to methods for their control are based almo.st entirely on 

 investigations and observations by the writer and by assistants in 

 the Bureau of Entomology working under his direction, carried on 

 in all of the principal forest areas of the United States. The his- 

 torical data have been gathered from the pul)lications listed on 

 pages 00-1)7. The estimates of the amount and value of standing tim- 

 ber killed by insects and of the forest products destroyed and reduced 

 in value through insect injuries to the crude and seasoned products 

 are based on our published results of investigations (pp. DT-IOO), on 

 unpublished notes, on technical an<l practical knowledge of the sub- 

 ject, and on the published forest statistics relating to the amount and 

 value of timber, (ire losses, etc. (pp. lOO-lOl). 



INSECT DEPREDATIONS IN NORTH AMERICAN FORESTS. 

 CIIAUAfTKIt AM) F.XTKNT OF DKI'KED.VriONS. 



The I't'cords of notable dcpi-cdat ions l»y insects on the tiiiii)er sup- 

 ply of ICurope during the past four hundred years, on that of the 

 (;is:;ir- 1^,11 :.<-},) r, 37 



