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MISC. PUBLICATION 273, U. S. DEPT. OF AGRICULTURE 



fire (fig. 90). The flames creep under the log and scorch the un- 

 peeled bark. If it is desired to dispose of the brush at the same time, 

 the limbs and top are cut off and piled back over the trunk. If this 

 would make too large and dangerous a fire, this material can be left 

 out and burned at a later time or spread on the ground to decay. As 

 a fire precaution, a fire line is constructed by scraping away all 

 the litter and duff down to the mineral soil for a width of about 

 3 feet and completely encircling the tree. In treating a tree in- 

 fested with the western pine beetle it is desirable to leave the stump 



Figure \)0. — After partial peeling, trees infested by the western pine beetle are burned. 



and the duff around it unburned in order to protect the beneficial 

 clerids in their pupal cells, which are usually concentrated around 

 the base of the tree. 



The fire should be allowed to consume the infested bark, but 

 should not be so large as to make it difficult to control. In wet 

 weather j^itch will have to be supplied to burn the bark sufficiently, 

 while in dry weather all tops, limbs, and even needles will have to 

 be thrown outside of the fire line in order to keep the fire from 

 becoming too large. In wet weather the burning should be with 

 the wind and uphill in order to create enough draft to consume the 

 bark; but in dry weather this should never be done,. but the burn- 



