30 



SCHOOL ENTOMOLOGY 



to the same class of animals and the young must, in 

 each case, be connected with their parents by observa- 

 tions of their life histories. 



The familiar form illustrating the indirect development 



is the common house-fly 

 or any butterfly. Here 

 the newly hatched young 

 is worm-like and in one 

 case entirely footless 

 and more or less helpless. 

 These young are called 

 larvce. The larvae grow 

 and moult from time to 

 time as do nymphs, but 

 they show little change 

 in form. Their colors may 

 change and there is often 

 some change in the cover- 

 ing of the body. 



After a larva has com- 

 pleted its growth it 

 changes into an inactive 

 object called a pupa. 

 This may be of various 

 forms. It may be naked 

 and exposed or enclosed 

 in some sort of cocoon or 

 case or buried in the earth. 

 It may be protected by 

 its own body wall, hard- 

 ened, smooth, and of a more or less oval, shape. 



Within the pupa-case all the changes between the 

 larval form and the adult form are accomplished. 



FIG. 14. Early Stages of Insects. 

 Reduced. 



1, Helgrammite or Dobaon-fly larva 

 (Neuroptera) ; 2, Pupa of the Spotted Pelid- 

 nota (Scarabceidce) ; 3, Cutworm (Noctuidce) ; 

 4, Slug-caterpillar (Eucleidce); 5, Corn ear- 

 worm (Noctuidce) ; 6, Pupa of round-headed 

 wood-borer (Cerambycidce); 7, Chestnut 

 worm (Curculionidce); 8, Larva of Rose- 

 chafer (Scarabceidce) ; 9, Larva of Colorado 

 potato^beetle (Chrysomelidce); 10, 11, Larvae 

 of Click-beetles (Elateridce): 12, Pupa of 

 Click-beetle; 13, Larva of Flesh-fly (Mus- 

 cina); 14, Imported Currant Saw-fly larva 

 ( Tenthredinidce) ; 15, Red-humped Apple- 

 caterpillar (Notodontidce); 16, Maggot of 

 Drone-fly (Syrphidae) ; 17, Larva of Papilio 

 philenor (Papilionidce) ; 18, Giant Root- 

 borer (Cerambycidce). 



