136 TREE WOUNDS AND DISEASES 



which are about an eighth of an inch long 

 and brownish in colour, bore into the stem 

 and larger branches for egg -laying. The 

 larva?, of a purplish colour, with brown head 

 and jaws, quickly hatch, and the perfect 

 beetle appears in August, the exit holes having 

 the appearance as if the bark was riddled with 

 shot. 



Ash logs that are allowed to lie about in a 

 plantation are the favourite haunts and breed- 

 ing ground of this beetle. Preventive measures 

 should be adopted in keeping this insect in 

 check, such as by keeping the woodlands free 

 of dead and dying ash timber, and removing 

 and burning infested bark during the summer 

 months. Two nearly allied species, the black 

 ash bark beetle (H. crenatus) and the ash branch 

 beetle (H. oleiperda] are found in Britain, but 

 their depredations are little dreaded by the 

 woodman. 



Tetroplum gabrleli. This beetle, which was 

 first recorded in Britain in 1902, is very de- 

 structive to larch timber, and is now reported 

 from many parts of the country. The eggs 

 are deposited in fissures of the bark, producing 



