144 



INSECT TRANSFORMATION 



texture, usually dark in colour and shortened, forms a more 

 or less rigid protective case, enclosing the pupa whose cuticle 

 is thin and delicate. Distinctive features of the maggot, 

 such as the arrangement of the spines on the segments and 



FIG. 84. LEAF-MINING MAGGOT OF ScaptomyZd 



a, lateral view ; b, dorsal view, x 30. c, front end, showing mouth-hooks, anterior spiracles, 

 and armature of cuticle ; d, e, tail-spiracles (lateral and dorsal views) ; /, tail-process, x 80. 

 g, Anterior spiracle of Puparium. xi2o. From Carpenter, Econ. Proc. R. Dublin Soc. II. 



the form of the spiracles (Fig. 84) can often be clearly recog- 

 nized on the puparium. It is noteworthy that the tail-spiracles 

 on which the maggot depends for its air-supply are closed in 

 the puparium, the functional spiracles, connected with the 



