LONGICORN BEETLES. 279 



#. Life-history, etc. 



It lays its eggs on oaks, but otherwise resembles the elm 

 beetle in its mode of life. It has, however, only one generation 

 in the year. 



It attacks several species of oak and more rarely the beech, 

 and it prefers young stems and branches 

 to older parts of trees. 



The beetle bores a simple gallery ; the 

 larval galleries, 30 to 40, run partly up- 

 wards and partly downwards, and are long 

 and narrow. The pupal chambers groove 

 the sapwood superficially. The beetles 

 attack perfectly healthy oak saplings and 

 kill them. 



In the Bois de Vincennes, several years 

 ago, about 50,000 30-year-old oaks were 

 killed by this beetle, which breeds freely Fi S- 137 - 

 in oak-posts which have not been barked, tus ' Ratz * 



and are used for fences. 



Care in the management of plantations of saplings, and 

 avoidance of unbarked wood in palings, are the chief protective 

 measures available. 



Two other species of Scolytus, S. pruni, Eatz., and 8. rugu- 

 losus, Eatz., the latter a very small species, are especially 

 attached to fruit-trees, plum and apple. Both are locally 

 common in England, and sometimes injurious, but they are 

 not important to the forester. 



FAMILY VIII. CEBAMBYCIDJB (LONGICOBN BEETLES). 

 Description of Family. 



Longicorn beetles are elongate, and generally of large or 

 moderate size, with a cylindrical thorax, often spined at the 

 sides ; elytra somewhat depressed, wider at the shoulders than 

 the thorax, and tapering behind. 



Antennae filiform or setaceous, rarely serrate, and always 

 becoming thinner at the ends, usually very long, with 11 or 

 more joints, the second joint always the shortest. 



Legs slender and long. Tarsi four- jointed, the three basal 

 joints flattened and spongy beneath, the third bilobed. 



