BEETLES. 175 



wood, throughout the winter season. About the com- 

 mencement of spring they assume the pupa 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 very fine sawdust. The last change of the insect 

 takes place, and being now winged, it tries to arrive 

 at the external air for the purpose of propagating 4^ 

 species, and laying its eggs in other trees. Each hole, 

 which now appears as if made with a gimlet, marks 

 the exit of a perfect insect. In the first instance the 

 voracity of the larvae, and in the second, the en- 

 deavours of the perfect insects to liberate themselves 

 from the wood, particularly when such attempts are 

 made by almost infinite numbers, soon occasion the 

 bark to fall in large pieces. The consequence is that 

 the new leaves only make their appearance to wither, 

 and the tree perishes. 1 



This is only one of several small beetles having 

 nearly identical habits, similar in form and size, but 

 with specific differences recognized by naturalists, 

 living at the expense of growing trees. All over 

 Europe they are recognized as the enemies of forest 

 trees, and constantly efforts are being made to reduce 

 the extent of their ravages. In 1842 it was stated 

 that there was scarcely a tree in the vicinity of North- 

 wich which did not show symptoms c f the decay in 

 consequence of the depredations of the little " Ash 

 Beetle." 2 This beetle pierces the bark, in the inner 

 part of which it forms a horizontal passage, and at 

 right angles to this passages on both sides of the 



1 W. S. Macleay. 2 Hykd^us Fraxini. 



