LIFE HISTORY OF INSECTS 



229 



Life History of the Grasshopper. — The female grasshopper lays 

 her eggs in a hole which she has dug in the ground with her ovi- 

 positor. From twenty to thirty fertilized eggs are laid in the 

 autumn; these hatch out in the spring as tiny wingless grass- 

 hoppers. The young molt, or shed their outer covering in order to 

 grow larger, each grasshopper 

 undergoing about five molts be- 

 fore reaching the adult state. 

 Since no great change in form 

 occurs, the metamorphosis is said 

 to be incomplete. In autumn 

 most of the adults die, only a few 

 surviving the winter. 



Life History of the Cabbage 

 Butterfly. — Although a frequent 

 visitor of our gardens, the cab- 

 bage butterfly is perhaps less 

 familiar than the earlier stage in 

 which it appears as a green cater- 

 pillar which eats the cabbage 

 leaves. 



Egg. The eggs are laid in the 

 early spring on the leaves of 

 young cabbage plants. They are 

 small, pale yellow, and delicately 

 marked with fine lines. 



Larva. In about a week the 

 egg hatches and a tiny caterpillar or larva crawls out. It has a 

 long segmented body, three pairs of small true legs on the first 

 three segments of the body, and five pairs of prolegs or cater- 

 pillar legs farther back, which are of great assistance in holding 

 on to a leaf. The mouth is provided with toothed mandibles 

 for cutting the leaves. The larva eats ravenously and grows 

 rapidly. 



Pupa. After two weeks of active life, the pupa, a resting stage, 

 is formed. The larva fastens itself to a cabbage leaf, fence rail, 

 or some other convenient object, and molts. As the skin sHps 

 off, the pupa — in this case called a chrysalis — appears. It 



H. NEW CIV. BIOL. 16 



Life history of the cabbage butterfly : 

 1, two eggs, highly magnified, on the 

 under surface of a leaf ; 2, larva ; 3, 

 chrysalis suspended at two points ; ^, 

 adult (male). 



