GROUND-BEETLES. 



19 



ing the old pupal skin behind, the young beetles reach the sur- 

 face. 



Among the most useful of the ground-beetles several de- 

 serve special mention, since they help us greatly to reduce cer- 

 tian injurious insects. The Caterpillar-hunter, {Calosonia 

 scrutator Fab.), is one of them. It is one of our largest and 

 most beautiful ground-beetles, having metallic green wing-cov- 

 ers, margined with reddish ; the rest of the body is marked with 

 violet, blue, gold, green, and copper. It is shown in Fig. 14. 



Fig. 14. — Calosoma, similar to C. scrutator, Fab., below a Carabvs. After Brehni. 



This insect ascends trees in search of caterpillars, ar|^ wherever 

 the tent-caterpillars, frequently so destructive in Minnesota, are 

 found in large numbers, the beetles will make war upon them ; 

 but few other insects care to attack and eat such hairy worms. 

 It is a pleasure to a person interested in the well-being of his 

 trees to watch this beautifully armored warrior catch a cater- 

 pillar, and holding the squirming object in its powerful jaws, 

 suck out its life-bfood. The empty skin of the victim is dropped, 

 and another unlucky worm is caught and treated in the same man- 



