CHAPTER XXI 

 INSECT ENEMIES OF TREES 



WHETHER viewed from a commercial or sylvicultural point 

 of view, the widespread damage caused to timber from insect 

 attacks can scarcely be overrated. The depredations in 

 various parts of our own country, particularly in young 

 plantations, are bad enough, but when compared with those 

 of Europe and America they appear insignificant. In 

 France and Germany whole woods have been wiped out by 

 insect pests, while the Government of Bavaria were mulcted 

 in something like 100,000 by the destruction of its spruce 

 forests. The United States fares no better, for we find that 

 over a period of ten years the amount of timber killed and 

 reduced in value was calculated at fully 10,000,000. The 

 coffee plantations of Ceylon suffered much from the attacks 

 of a fungus, and we could go on multiplying cases. In our 

 own country the ravages of the pine beetle and of the larch 

 disease have caused incalculable damage ; indeed, in the 

 latter case there is hardly a plantation of larch where the 

 presence of the fell disease cannot be distinctly traced, 

 while the pine beetle has ruined whole plantations both in 

 England and Scotland. Though the adult bark and wood- 

 boring beetles do a great amount of damage, yet that in- 

 flicted by the caterpillar or grub from the egg is greater 

 still, and in the case of fungi we have a typical example of 

 their destructive properties in the case of the well-known 

 larch disease. 



The Pine Beetle (Myelophilus (Hylurgus) piniperda) is 

 a dreaded enemy to not a few species of Pinus, but particu- 

 larly P. sylvestris, P. laricio, P. austriaca and P. Strobus. 

 The injury done by this beetle consists in its destruction of 



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