20 GROUND-BEETLES. 



ner. The appetite of the beetles is truly without limit, and they 

 eat all day if they have an opportunity to do so. It is too bad 

 that they are not more numerous in all our orchards and forests 

 in the north ; they are confined to the more southern parts of 

 the state. 



Another species of caterpillar-hunters, (C. frigidum Kirby), 

 is, however, very numerous in the northern part of Minnesota. 

 It climbs trees as well as the one described, but it is of a black 

 color, (Fig. 15). Wherever canker-worms abound large num- 

 bers of these beetles congregate, and they climb trees in search 

 of them- They detect such worms some distance aw^ay, and 

 rushing over twigs and leaves, frequently succeed in catch- 

 ing them before their victims have an opportunity to drop and 

 hang suspended by silken threads. It is amusing to observe, if 

 unsuccessful, how the baffled hunters try to grasp such a thread 

 with their front feet in wdiich not infrequently they succeed. 

 Others are stationed below the tree, and many of the worms 

 that descend from the defoliated branches to enter the ground 

 for pupation are caught before doing so. The larvae of both 

 the above described beetles are also equally active and beneficial. 

 Though they do not climb trees they do good work above and 

 below the surface of the soil, always hunting about to find 

 some insects to eat. Another lieetle of the same genus, the 

 "Fiery Hunter" (C. calidum Fab.), is frequently seen search- 

 ing for cut-worms and other food in the grain-fields in our 

 open prairies. It is readily recognized by its black wing-covers 

 with rows of reddish or copper-colored pits. It is illustrated in 

 Fig 13, \^th its larva. 



When we turn over loose stones and boards lying about 

 the edges of fields and orchards, we frequently discover rather 

 large black beetles having thorax and wdng-covers bordered with 

 blue. They seem to be very slow in their actions, and do not 

 usually attempt to escape. But not everyone likes to pick them 

 up with the fingers, as they have a sort of dangerous look about 

 them, possessing very formidable jaws. These insects are very 

 useful, and locust-infested fields contain them in large num- 



