COLEOPTERA. 597 



with many the hind end of the body is very blunt, as if cut 

 off. The antennae are elbowed or bent in the middle, and 

 are clubbed at the tip ; the tibiae are usually serrate ; the 



FIG. 728. 



pygidium is surrounded at the edge by the wing-covers, 

 which have the fold on the inner surface well developed. 



The members of this family feed almost exclusively on 

 woody plants. Most of the species make burrows between 

 the bark and the wood ; but many species bore directly into 

 the solid wood, and one well-known pest lives in the roots 

 of herbaceous plants. 



In the case of the kind of burrow figured above and other 

 similar ones the central tunnel is made by the mother 

 beetle. While doing this she makes a series of niches along 

 each side of this tunnel, and lays an egg in each. When the 

 larvae hatch, each one deepens its niche, and thus makes a 

 burrow at right angles to that of the parent beetle. 



In the case of a European species, Touiicus typogra- 

 pJins (Tom'i-cus ty-pog'ra-phus), Dr. K. Lindeman, a Russian 

 naturalist, has discovered that the original tunnel is be- 

 gun by the male, which makes a little chamber in the bark ; 

 afterwards the female comes to him in this chamber, and 

 later she continues the mine begun by her mate, making the 

 long central tunnel from which the tunnels of her offspring 

 extend. Thus we see that all of the members of a single 



o 



family have a share in making one of these engravings. It 



