DEVELOPMENT ast4 
doptera), “ grub” (Coleoptera), and “ maggot” (Diptera), 
while the pupa of a moth or butterfly (especially the latter) 
is called a “ chrysalis.”’ 
Heterometabola.—In a grasshopper, as contrasted with a 
butterfly, the imago, or adult, is essentially like the young at 
birth, except in having wings and mature reproductive organs, 
and the insect is active throughout hfe; hence the metamor- 
phosis is termed direct, or incomplete. This type of trans- 
Fic. 204. 
Phormia regina. <A, larva; B, puparium; C, imago. xX 5. 
formation, without a true pupal period, is characteristic of 
the more generalized of the metamorphic insects, namely, 
Orthoptera, Platyptera, Plecoptera, Ephemerida (Fig. 19), 
Odonata (Fig. 20), Thysanoptera and Hemiptera (Fig. 205). 
These orders constitute the group Heterometabola. Within 
the limits of the group, however, various degrees of meta- 
morphosis occur; thus Plecoptera, Ephemerida and Odonata 
undergo considerable change of form; a resting, or quiescent, 
period may precede the imaginal stage, as in Cicada (Fig. 
