INSECT METAMORPHOSIS 



the wings and the organs of reproduction. As might be 

 expected, therefore, the young grasshoppers and the 

 adults live in the same places and eat the same kinds of 

 food in the same way. This likewise is true of the roaches, 

 the katydids, the crickets, the aphids, and other related 



B 



Fig. 131. A May beetle and its grub 



A, the adult beetle which feeds on the leaves of shrubs and trees. 



B, the larva, a white grub, which lives in the ground and feeds 



on roots 



insects. The adults here take no advantage over the 

 young in matters of everyday life by reason of their 

 wings. 



In many other insects, however, the adults have 

 adopted new ways of living and particularly of feeding, 

 made possible and advantageous to them because of their 

 power of flight. Then, in adaptation to their new habits, 

 they have acquired a special form of the body, of the 

 mouth parts, or of the alimentary canal. But all such 

 modifications, if thrust upon the young, would only be an 

 impediment to them, because the young are not capable of 

 flight. Take the dragonflies as an example. The adult 

 dragonfly (Fig. 58) feeds on small insects which it catches 

 in the air, and it can do so because it has a powerful flying 

 mechanism. The young dragonfly (Figs. 59, 134), how- 

 ever, could not follow the feeding habits of its parents; if it 

 had to inherit the parental form of body and mouth parts 



