188 MISC. PUBLICATION 2738, 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 hmbs 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 
eo 
FIGURE 90.—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 pitch 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- 
