17 s [XSBCTfl INJURIOUS TO FOREST TREES. 



be kept for the enemy ; and whenever lie makes his appeai*ance, 

 attack him at once, and get rid of him by picking and bm*ning 

 as quickly as possible, to save the trees from irretrievable injury 

 to their health and symmetry. I have noticed that the Hylurgus 

 seems to have a partiality for trees growing in a dry, warm soil ; 

 and one of the worst infested trees of Pinus insignis I have ever 

 met with, grew on the top of a dry steep slope on a gravelly sub- 

 soil, where for several years it was severely attacked by the beetle, 

 while others growing in a deep and moister soil, in a hollow near 

 by, were scarcely touched. I have also observed the same thing 

 occur in other similar situations, and with other species of pine ; 

 but those having greater experience with the beetle amongst 

 Scotch fir will be able to say whether or not this partiality of the 

 beetle for dry spots is characteristic. 



Several species of bark beetles commit great devastation amongst 

 trees and shrubs by boring into the young wood or alburnum, and 

 perforating it in all directions, thereby cutting off or interrupting 

 the flow of the sap, and causing the death of the tree. Bostrichus 

 topographies attacks the pine tribe, especially the silver fir, and 

 works extensive mischief under the bark, where it cannot be easily 

 detected until it is too late to apply any remedy, if such was prac- 

 ticable. Of the same nature are Bostrichus pino.stri, B. laricis, 

 and B. orthography.?, which prey upon the alburnum of the pine, 

 larch, and silver fir. Scolytus ligniperda also attacks the albur- 

 num of some of the conifers. Some years ago great fears were 

 expressed that the ravages of Scolytus destructor would destroy 

 the fine old elms in Hyde Park and other places about the west 

 end of London. Various means were suggested, and experi- 

 ments tried, to stop its ravages, and if possible to exterminate it 

 without sacrificing the trees, but none of the plans tried could be 

 said to be really successful, nor were they of such a nature as to 

 recommend them as generally applicable. Scolytus intricatus 

 attacks the oak, S. vittatus the lime, S. fraxini the ash, and so 

 on, all doing injury in the same manner by perforating the albur- 

 num of the trees they live upon. 



The grub or larva of the cockchafer (Jfelolontha vulgaris) devours 

 the young roots and soft bark of the larger roots of trees ; and as 

 they remain about four years in the grub state, they commit sad 

 havoc where they are numerous. As soon as they arrive at the 

 fully-developed state of a beetle, they immediately commence a 

 ravenous attack on the leaves of trees, preferring the oak when 



