50 OUR HOUSEHOLD INSECTS 



which all the damage is effected. The pupa is formed 

 in the burrows. 



Fir palings in gardens sometimes produce plentiful 

 supplies of a most lovely beetle, the resplendence of 

 whose appearance is such as to suggest, though falsely, 

 an acquaintance with the glowing rays of a tropical 

 sun, instead of the comparatively feeble beams with 

 which Old England is favoured. It is entirely of a 

 most lovely violet or deep blue colour, and is shaped 

 not unlike Hylotrupes, but flatter, and with longer 

 antennae. In allusion to its colour, it is called Calli- 

 dium violaceum. 



Here is a marvel in physiological chemistry ! The 

 larva is absolutely white, except for its little black 

 jaws; there is not a trace of blue or any other colour 

 about it, even up to the very time when it ceases 

 feeding and changes into a chrysalis; and yet, during 

 its larval existence, has been stored up in its body 

 something from which, by the changes that take place 

 during the pupal stage a period during which no addi- 

 tional nutriment is taken is elaborated the gorgeous 

 hue which glorifies its adult form. 



Longicorns are frequently very variable in size, as is 

 usually the case with wood-boring insects. Imprisoned 

 as they are in a burrow which, as larvae, they never 

 leave, they have very little power of selection of food, 

 and are, therefore, entirely dependent upon the supply 

 into the midst of which their excavating labours carry 

 them ; and according to the quality of this will be the 

 vigour, or otherwise, of their constitution, and the 

 stature to which they will attain. 



We have only one other group from which to select 

 examples of British household Coleoptera. These are 



