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
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), however, could not follow the feeding habits of its parents; if it had to inherit the parental form of body and mouth parts
[ 233 ]
