80 ON THE MOST CERTAIN METHOD OF 



IX. On the most certain Method of getting rid of Beetles which 

 affect Coniferm. By William Tivendale, Forester, Hous- 

 ton, Paisley. 



In the spring of 18G5, I was requested by a landed proprietor to 

 look at three young plantations which were very much damaged by 

 the ravages of insects, and to suggest if anything could be done to 

 get rid of them. 



On inspecting these plantations, I found that the trees had been 

 three } r ears planted, on ground previously occupied by a crop of trees, 

 principally Scotch pine, and that the insects which had done so much 

 damage to the trees were the wood beetles — Hylobius abietis of 

 Germar, and HyJurgus piniperda of Fabricius, two of the most 

 destructive pests that arboriculturists have to contend with. 



The number of trees destroyed by these beetles exceeded 140,000. 

 In tract No. 1, extent 16 acres, planted with Scotch and Austrian 

 pines, larch, and a few spruce and silver firs, at 3 feet apart, more 

 than half of the trees were completely destroyed ; in tract No. 2, 

 extent 13 acres, planted at 3 feet apart, with Scotch pine, larch, and 

 a few spruce, more than two-thirds were rendered useless; and in 

 tract No. 3, extent 14^ acres, not a living plant was seen, save about 

 a dozen of larches in a corner of the plantation which was a little 

 damp, and even these were injured to such an extent that they did 

 not look likely to live over the summer. 



On reporting this state of matters to the proprietor, he expressed 

 his determination to get rid of the pests, if possible, in No. 1 and 

 No. 2 plantations; but, as there were no plants in No. 3 worth 

 saving, he put cattle in to graze for a year or two, to see if that would 

 tend to diminish the evil. 



Hylobius abietis is \ inch long, ^ inch in circumference, of a 

 bright grey colour, and beautifully spotted over the cases of the 

 wings. It makes its depredations upon all sorts of Conifers, but the 

 Scotch pine is, doubtless, its favourite. In its attack upon the tree, 

 it generally begins immediately above the surface of the ground, and 

 eats greedily the bark all round, and gradually upwards, leaving the 

 trees peeled into the alburnum, when they soon die. In the case of 

 older trees, it makes no attempt to eat the rough bark on the bole, 

 but seeks its way to the branches, and preys upon their tender bark. 

 Here it does not eat the bark all round as it does on the stems of 

 the young tree, but makes an attack here and there on the upper 



