68 THE LIFE-STORY OF INSECTS [CH. 



A 



A 



Fig. 19. Larva of Gall-midge 

 (Contarinia nasturtii), ven- 

 tral view, showing anchor 

 process (), and spiracles 

 projecting at sides. Mag- 

 nified 30 times. From 

 Carpenter, Journ. Econ. 

 BioL vol. vi. 



type known as the maggot, 

 not only legless, but without 

 a definite head, the front end 

 of the creature usually taper- 

 ing to the mouth, where there 

 are a pair of strong hooks, 

 used for tearing up the food. 

 A few examples of each 

 of these types must suffice 

 in the present brief survey. 

 A few pages back (p. GO) 

 reference was made to the 

 production of galls on various 

 plants, through the activity 

 of larvae of the hymenopte- 

 rous family Cynipidae. Many 

 plant-galls are due, however, 

 to the presence of grubs of 

 tiny dipterous insects, the Ce- 

 cidomyidae or Gall-midges. 

 A cecid grub (fig. 19) has an 

 elongate body with flexible, 

 wrinkled cuticle, tapering 

 somewhat at the two ends. 

 The head, if rather narrow, 

 is quite distinct, and beneath 

 the prothorax is a charac- 

 teristic sclerite known as the 



