CHAPTER XXXI 



INSECTS AND DISEASES INJURIOUS TO FOEEST TREES. 



THE Pine Beetle (Myelophilm (Hylurgus) piniperda) is a 

 dread enemy to not a few species of Pinus, but particularly 

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

 injury done by this beetle consists in its destruction 

 of the leading shoots of the tree it attacks. It enters by 

 boring a hole into the side of the shoot until it reaches 

 the pith, after which the course is directed upwards, and 

 an exit made at the terminal bud. This tunnelling of 

 the shoot so weakens it that frequently during stormy 

 weather it is broken across at the point where the beetle 

 entered. Not only are unhealthy trees attacked by the pine 

 beetle, but young and robust-growing specimens frequently 

 fall a prey to its insidious depredations. 



, June, July, and August are the months when it is most 

 commonly found. 



The only remedy is collecting and burning the affected 

 shoots work that requires to be done with the utmost care 

 to prevent the escape of the wary insect. Burning all brush- 

 wood in plantations is a great, preventive. 



.The Pine Weevil (Gurculio (Hylobius] Abietis) is another 

 destructive insect, and differs from the former in waging its 

 attacks against the buds of the leaders and branches, as also 

 by eating patches of the bark here and there on the stems 

 and branches. The various species of Abies suffer most, but 

 the pines occasionally are attacked as well. It is always 

 most destructive in young plantations growing on the mar- 

 gins of old woods, and equally bad amongst trees that have 

 been planted on the site of a former pine plantation. 



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