is changed , Cull logs also breed this species. 



Yellow pine cull logs have been found on all 



sales examined, breeding the tree -killing Western Pine Beetle, 

 (Dendroctonus brevicomis). Sugar pine cull logs breed the 

 Mountain Pine Beetle (Dendroctonus monticolae) , and both spe- 

 cies breed in the tops left on the area. Tops and limbs 

 breed quantities of all species of Ips, especially Ips con- 

 fusus, and eventually attach tops of trees and pole and sap- 

 ling stands. Preference for freshly cut material seoms to 

 hold good with all the bar 1 : beetles, no matter what the spe- 

 cies of conifer, Stebbing, one of the best English forest 

 entomologists, writes in his Indian Forest Menoirs: 



"Experience has shown that in countries where 

 very large tracts are covered with a single species of a 

 conifer, e.g., as in the cace in America, and to a lesser 

 extent perhaps in India, uncontrolled fellings havs re- 

 sulted in the most disastrous infestations of bar!: -boring 

 beetle pests. " 



No matter where the stumps, cull logs, limbs and 

 brush occur the particular species infesting that species of 

 tree will breed in enormous quantities if the material is 

 freshly cut. If these beetles cannot find freshly out materi- 

 al they will attack standing timber. The future of the forest 

 often depends very largely upon the right choice of seed trees 

 Of what use are such seed trees if cull logs, stumps, brush, 

 etc., are left in a condition to insure the infestation of 

 these seed trees. 



-55- 



