132 SYLVAN SKETCHES. 



Evelyn commends Elm timber for a variety of pur- 

 poses, on account of its toughness and long durance in 



destroyed in the parks, but may have to regret the dissemination of 

 the evil throughout the vicinity of London. 



" In St. James's Park, which has more particularly been subject 

 to my examination, there are several species of beetles to be found 

 attacking the Elms. That species, however, which occasions all 

 the havoc we have now to lament in the Mall and Bird Cage 

 Walk is the Hylesinus destructor of Fabricius, or Scolytus destructor 

 of Latreille ; an insect of which the history is briefly as follows : 



" A small beetle, with its head rather covered with hair, having a 

 polished black thorax, and brown wing-cases, may be seen in num- 

 bers running over the trunks of the Elms, from the end of March 

 to the first days of July ; but principally about the end of May, or 

 commencement of June. It may then be seen entering into holes, 

 with which the bark is perforated as though with a gimblet. It 

 insinuates itself into these holes, or into the crevices of the bark, 

 for the purpose of depositing its eggs. On stripping off a piece of 

 the loose bark, we may easily, at any season, understand how the 

 barking of trees is effected by these minute animals, for the surface 

 of the wood thus exposed presents to the view innumerable impres- 

 sions, which may be compared to impressions or casts of large and 

 broad scolopendrae. 



" The middle or body of this singular impression marks the 

 path of the perfect female insect, while employed in laying her 

 eggs, which is to her, as to most winged insects, the forerunner of 

 death. From this tubular path, however, in which she deposits her 

 eggs, the lurvae, which are hatched from these eggs, in the shape 

 of little white apod worms, proceed nearly at right angles, eating 

 their way in parallel smaller tubes, which, lying close to each other, 

 effectually serve to separate the bark from the tree. The larva? 

 remain feeding in the tree, generally between the bark and the wood, 

 throughout the winter season. About the commencement of spring 

 they assume the pupa or nymph state, and, before the end of this 

 season, the bark of an infected tree begins to appear as if all its 

 crevices were full of a fine saw-dust. The last change of the insect 

 takei place ; and, being now winged, it tries to arrive at the ex- 



