DAMAGE CAUSED BY ANIMALS. 131 



Spruce Moth (Liparis monacha), which first attack older woods, 

 and then in their voracity proceed to denude younger woods of 

 their foliage. 



With reference to the extent of the injury each species does 

 on the average, attempts have been made to divide them into 

 very injurious, noticeably injurious, and slightly injurious, accord- 

 ing as they occur more or less frequently, and usually in more or 

 less numerical strength. Such a classification has, however, little 

 to recommend it ; it is apt to be extremely elastic, and under any 

 circumstances indefinite. 



But at the same time there are numerous insects, which, on 

 account of the extensive and often calamitous injuries they have 

 from time to time done in woodlands, must undoubtedly be 

 considered as very injurious species. These include in particular the 

 large 8-toothed or Spruce bark-beetle (Bostrichus typo- 

 graphies), 1 the large brown rostral-beetle or Pine weevil (Hylobius 

 abietis), the cockchafer (Melolontha mdgaris), the large Pine Moth 

 (Gastropacha pini), and the Black Arches, " Nun/' or Spruce Moth 

 (Liparis monacha). And along with these there are also others 

 which have in certain localities committed such devastations in 

 woodlands, as might justify their being included among the very 

 injurious species ; these include the Pine Owlet-moth or Pine 

 Beauty (Trachea piniperda), the Pine Span-worm or Bordered 

 White Moth (Fidonia piniaria), me Pine Sawfly (Lophyrus pini), 

 the small, brown, white-spotted rostral-beetle (Pissodes notatus), 

 and others, which, under ordinary circumstances, are reckoned as 

 noticeably injurious species. Between this latter class and the 

 slightly injurious species, the borderland is still more indefinite. 

 It has, therefore, seemed best on the whole to adopt a different 

 classification below, to consider the chief insect enemies in 

 i two main groups namely, Insects on coniferous trees and Insects 

 | on broad-leaved species of trees, and to treat of them within these 

 groups under the special headings of beetles, Moths, and other 

 ; kinds of Insects. 



1 In the Highland and Agricultural Society of Scotland's Transactions for 1887, 

 j Fourth Series, vol. xix. p. 186, footnote, it is remarked by one of the Prize Commit- 

 tee on Forest Reports that B. typographus is "not in any of the entomological lists 

 for Scotland," a fortunate thing for the Pine and Fir forests of the North. Trans, 



