10 



After the birth of an insect, or the hatching from the 

 egg, it goes through changes and developments before reach- 

 ing the fully developed or adult condition. This change and 

 development is called the metamorphosis. Metamorphosis 

 may be either complete or incomplete. This does not mean 

 that development stops short of the perfect insect, in the case 

 of insects which have incomplete metamorphosis, but rather 

 expresses a general difference ^between these two kinds of 

 development. 



Insects which have an incomplete metamorphosis are 

 something like the adult when they are first hatched from 

 the egg. (Fig. 9, young and adult cockroaches.) They are, 

 of course, much smaller, and without wings, but in general 

 form they give an idea of what they will be like when they 

 are full-grown. Insects which have a complete meta- 



Fig 1 . 10. Insect with complete metamorphosis. The bean leaf-roller. 

 (a) butterfly ; (b) larva, dorsal view ; (c) larva, lateral view ; ( 1} pupa in 

 rolled-up leaf. Somewhat enlarged. (From U. S. Dept, Agric.) 



morphosis are very different, when first hatched, from 

 the adult form into which they finally develop. Such 

 insects have four distinct stages, or periods in their 



