THEIR RELATION TO EACH OTHER 101 



an alternate, and a very few seem confined to a plant 

 diet; but, as a whole, this immense series of species 

 feeds on other insects in both larval and adult stage. 

 Most of them are rather general feeders, taking all 

 things that come in their way, and they are not at all 

 particular whether this prey is another predatory form 

 or a plant feeder. And we have species that frequent 

 trees, shrubs and flowers as well as those confined to 

 the ground: the smaller forms capable of feeding only 

 upon eggs, the larger climbing trees for the caterpillars 



FIG. 44. A caterpillar- hunting ground 

 beetle and its larva. 



FIG. 45. A common type 

 of ground beetle. 



to be tound on them. Some of the species have the 

 advantage of being able to adapt themselves to the 

 conditions found in cultivated fields and orchards and 

 the number of larvae and pupae of plant-feeding forms 

 that go under ground for pupation or hibernation that 

 are destroyed by them is beyond all computation. 

 While I do not recollect at this time any species that 

 devotes itself to any one particular kind of prey, there 

 is no sort of doubt of the reality of the check which the 

 ground beetles exercise over the increase of plant- 

 feeding forms ^especially those which pupate on or 

 under the surface. But we must limit this praise just 



