INSECTS 



29 



Fig. 20. — Stages in life history of a grasshopper. 



oyipositor (Fig. 19). From 20 to 40 small, banana-shaped 

 eggs are then laid in the bottom of the hole. In the spring 

 each egg hatches into a tiny grasshopper, which much re- 

 sembles the adult, except that it has no wings and its head is 

 relatively large in comparison with the rest of the animal. 

 The insect begins at once to feed and grow, but since its 

 whole exterior is hard and resistant, growth can only take 

 place after this outer covering has been split and the insect 

 has crawled out. This process is known as molting, and takes 

 place five or six 

 times during the 

 life history of the 

 animal. The insect 

 then forms a new 

 and larger coat. 

 At each molt the 

 wings become more 

 fully developed, until at the last molt the adult insect 

 is produced (Fig. 20). Hence, in the life history of the 

 grasshopper there are three more or less distinct stages : 

 (1) the egg, (2) the developing insect, which is known 

 as the nymph, and (3) the adult grasshopper. This suc- 

 cession of .changes in a life history is known as meta- 

 morphosis (Gre^k, meta = one after another -|- morphos = 

 form). But, because in the development of the grasshopper 

 these changes are not so striking as those that occur in the 

 life history of the butterfly (11), the metamorphosis of the 

 grasshopper is said to be incomplete. It is better, however, 

 to refer to it as a direct metamorphosis, that of the butter- 

 fly being known as an indirect metamorphosis. After reach- 

 ing the adult stage and depositing eggs, the adult insects die. 

 Only a few of the immature grasshoppers survive the winter, 

 and these are the grasshoppers that are seen early in Spring. 



