TOMICUS LINEATUS. 



257 



Dee districts of Scotland, where it has not as yet proved 

 injurious. 



c. Relations to the Forest. 



The beetle attacks all conifers, but chiefly the silver-fir and 

 spruce, and only large trees. The round-bored gallery pene- 

 trates at right angles to the axis of the tree. It consists of 



Fig. 116. Transverse sec- 

 tion of a spruce-stem (re- 

 duced) with burrows of 

 T. lineatus, Oliv. (Natural 

 size.) 



a Entrance-galleries. 



b Breeding-galleries. 



Fig. 117. Radial burrows of 

 T. lineatus, Oliv., in spruce- 

 wood. (Natural size.} 



a Mother galleries. 



b Larval galleries and pupal 

 chambers. 



an entrance passage and breeding-gallery. The latter is either 

 merely a prolongation of the former, or is usually composed 

 of two branches, which generally follow the annual zone of 

 the wood in the same plane. It is rare that several annual 

 zones are traversed by it. The entrance gallery is generally 

 confined to the sap wood. The larvae on emergence feed on 

 the sap of the wood, and by gnawing extend their egg 

 chambers to short cylindrical tunnels in which they pupate. 



F.P. 



