18 



GROUND-BEETLES. 



joints which are nearly uniform in thickness throughout their 

 length. The legs, with but few exceptions, are adapted for run- 

 ning, which some of them do with amazing rapidity. In fact all 

 the senses of these beetles are very acute. Ground-beetles are dis- 

 tinguished at a glance from the tiger-beetles by having their heads 

 narrower than the pro-thorax. They depend more upon their legs 

 for locomotion than upon their wings, and but very few fly readily. 

 Some have lost their true wings almost entirely, and in such cases 

 the elvtra are soldered together at the surface on the back. 



Fig. 15. — Calosoma frigidum. 

 Original. 



Fig. 13. — Calosoma calidvm, FalD., and 

 a larva of another species. 



The larvse (Fig. 13) are mostly long, flattened grubs, with 

 a body of almost equal breadth throughout. The latter is 

 usually protected on top with horny plates, and ends in a pair 

 of conical and bristly appendages. Most of the larv?e exist in 

 the same obscure situations in which the adults live, and they 

 burrow just beneath the surface of the earth. Here they de- 

 stroy large numbers of the soft leaf-feeding insects, which 

 have entered the ground for transformation. Like the adults, 

 they are predacious. Others may, perhaps, also feed upon 

 some vegetable food like the adults, but they cause no losses of 

 any great economic importance. When fully grown they trans- 

 form to pupae under ground, where they have formed small 

 cells for this purpose. Soon afterwards the pup?? change from 

 almost white to the distinguishing colors of the adults, and leav- 



