Canadian Forestry Journal, June, IQ16. 



565 



Back of Peachland, B, C. Black Pine Killed by Mountain Pine Beetle, 



there are piled over two million feet 

 of good white spruce logs in a series 

 of immense piles. Two of these piles 

 had been cut two and a half years 

 previous to our visit and the re- 

 mainder one and a half years, or two 

 winters before. The outer layers of 

 logs in the piles cut latest were in- 

 fested with countless numbers of 

 the grubs then boring actively and 

 audibly from four to six inches be- 

 low the surface. The large amount 

 of fresh boring-dust from the tun- 

 nels and lying everywhere between 

 the logs gave evidence of the de- 

 strucive work going on beneath the 

 bark. On the older piles the outer 

 layers of logs were completely ruin- 

 ed by the tunnels of the grubs, 

 which had penetrated the heart 

 wood and often passed completely 

 through the trunk. At the time of 

 our visit — July. 1915 — the grubs had 

 completed their two year's growth, 

 transformed to adult beetles and all 

 emerged from the logs of these older 

 piles. Hundreds of thousands of 

 feet of excellent .white spruce had 

 already been destroyed by borers in 

 those piles, and much further injury 

 will be done if no effort is made to 

 prevent it. The whole loss could 



have been averted very simply by 

 booming the logs in a nearby cove 

 during the spring following the cut. 



Jn the Wake of Fires. 



Losses from these large boring 

 grubs occur frequently in pur spruce 

 and pine limits, when logs are left 

 behind in the woods. Fire-killed 

 and wind-blown pine, spruce and 

 balsam in our woods are usualy at- 

 tacked by these beetles and the tim- 

 ber rendered useless within two sea- 

 sons following the fire or storm. 

 Fire-killed standing trees would re- 

 main excellent timber for many 

 years if not attacked by insects and 

 fungi or swept by succeeding fires. 



Ambrosia-beetles excavate round 

 tunnels about the size of the lead in 

 a lead pencil deep into the wood of 

 both deciduous and coniferous trees. 

 The walls of the tunnels are stained 

 black by a ftingus which always 

 grows thereon. The loss in reduc- 

 tion of value is at times very im- 

 portant. The most destructive of 

 these borers, because its tunnels ex- 

 tend deepest into the wood, is the 

 Pacific Coast Timber-beetle, Play- 

 pus zi'ilsoni, found in the coast region 

 of British Coltimbia. It extends its- 



