fl 



tonus brevicomis and Dendroctonus monticolae breed in 

 large numbers. Those logs als^> breed destructive flathead 

 borers. 



Tops:- VThile other tree -killing beetles often breed in tops 

 left on the ground, the chief danger from this source is from 

 various species of Ips which afterward attack polen, saplinps, 

 and tops of mature trees. 



Limbs:- In order to keep down the cost of brush piling in 

 timber sales large limbs have often been trimmed and left on 

 the ground. These limbs, especially in yellow and sugar pine, 

 breed large numbers of Ips confusus, one of the most destruc- 

 tive insects in District 5, also other Ips species and vari- 

 ous i lathe ads. 



Brush or Slash:- Nearly all brush if left on the ground for 

 any length of time, besides being a fire menace, breeds a 

 myriad of injurious insects that kill poles, saplings, t'ops 

 of mature trees, individual limbs and twigs on otherwise per- 

 fectly healthy trees. These insects belong to the various 1^; 

 Eccoptogaster , Hylesinus anfl numerous other species of the 

 genera Pityophthorus, Pityogenes, Ilagdalis, Pissodes*, etc. 



See "Contributions toward a Honograph ^f the Bark Weevils 

 rf the Genus Piss*x1es", by A. D. Hopkins, Technical Series 

 No. 20, Pt. 1, Bureau of Entomology. 



