COLEOPTERA 



i37 



tions as the adult insects, but are more shy, and are consequently less 

 frequently seen. Like the adults, they are predacious. 



Among the more common ground-beetles are the following. 



The searcher, Calosoma scrutator. — This is one of the larger and more 

 beautiful of our ground-beetles; it has green or violet wing-covers 

 margined with reddish, and the rest of the body is marked with violet- 

 blue, gold, green, and copper (Fig. 225). This beetle and the two follow- 

 ing have been known to climb trees in search of caterpillars. 



Fig. 225. 



Fig. 226 



Calosoma sycophanta, a common species in Europe, has been intro- 

 duced and successfully colonized in New England, as a means of com- 

 bating the gipsy-moth and the brown-tail moth. This species is 

 somewhat smaller than the preceding, and lacks the reddish band on 

 the margins of the elytra. 



The fiery hunter, Calosoma cdlidum, is easily recognized by the rows 

 of reddish or copper-colored pits on the wing-covers (Fig. 226). 



The bombardier-beetles,' Bracklnus. — There are many species of 

 beetles that have at the hind end of the body little sacs in which is 

 secreted a bad-smelling fluid, which is used as a means of defence. These 

 beetles spurt this fluid out onto their enemies when attacked. But in 

 the case of the bombardier-beetles this fluid changes to a gas, which looks 

 like smoke as soon as it comes in contact with the air, and is ejected 

 with a sound like that of a tiny pop-gun. When some larger insect tries 

 to capture one of these insect-soldiers, and gets very near it, the latter 

 fires its little gun into the face of its enemy. The noise astonishes the 

 pursuer, and the smoke blinds him. By the time he has recovered from 

 his amazement, the little bombardier is at a safe distance. 

 These beetles have quite a store of ammunition ; for we have 

 often had one pop at us four or five times in succession, 

 while we were taking it prisoner. The bombardier-beetles 

 belong to the genus Brachinus, of which we have in this 

 country twenty-seven species. They are very similar in ap- 

 pearance; the head, prothorax, and legs are reddish-yellow, 

 and the wing-covers are dark blue, blackish, or greenish-blue (Fig. 227). 



There is a common beetle which resembles the bombardier-beetles 



