PLAN FOR INSECT STUDY 



49 



pupa case is split open on the back, and the adult insect 

 emerges ; the fourth and last stage begins. The adult 

 female lays the eggs, and the life story from egg around 

 to egg again is completed. This change of form in insects 

 is called "metamorphosis." 



A few insects hatch out from the egg more nearly like 

 their parents in 

 form. Children 

 will notice this 

 in the case of 

 their grasshop- 

 per or water-bug 

 eggs. Insects 

 that do not 

 thus completely 

 change their 

 form are said 

 to present an 

 incomplete 

 metamorphosis, 

 and the young 

 in all stages are called " nymphs " instead of larvae. 



With our insect enemies it is important to learn the 

 whole life story in order to find the weakest point, at which 

 we may most easily attack and destroy them. We shall 

 endeavor always to point this out for the insects described, 

 but it will be possible to give only a few which happen to 

 be of greatest importance at present in order to illustrate 

 a method for insect nature study. The best rule to follow 

 is to study the insects that happen to be of most impor- 

 tance or of greatest interest for any locality or season. 



FIG. 14. ADULT CECROPIA ON COCOON 

 (2 natural size) 



