DEVELOPMENT 



and Meloidae). These primitive characters are gradually overpowered, 

 in the course of, larval evolution, by secondary, or adaptive, features. 



FIG. 211. Types of larvae. A, B, Thysanura; C, D, thysanuriform nymphs; E-I, cruci- 

 form larvae. A, Campodea; B, Lepisma; C, perlid nymph (Plecoptera) ; J9, Libellula (Odo- 

 nata); E, Tenthredopsis (Hymenoptera) ; F, Lachnosterna (Coleoptera) ; G, Melanotus 

 (Coleoptera) ; H, Bombus (Hymenoptera); 7 5 Hypoderma (Diptera). 



Eruciform Larvae. The prevalent type of larva among holometab- 

 olous insects is the cruciform (Fig. 211, E-I}, illustrated by a caterpillar 



FIG. 212. Mantis pa. A, larva at hatching thysanuriform; B, same larva just before 

 first moult now becoming cruciform. C, imago, the wings omitted; D, winged imago, 

 slightly enlarged. A and B after BRAUER; C and D after EMERTON, from Packard's Text- 

 Book of Entomology, by permission of the Macmillan Co. 



or a maggot. Here the body is cylindrical and often fleshy; the integ- 

 ument weak; the legs, antennae, cerci, and mouth parts reduced, often 

 to disappearance; the habits sedentary and the sense organs correspond- 



