186 OTHER MEMBERS OF THE CLASS — INSECTA 



Through this tube, they take in 

 the air. They Uve in this manner 

 for about a week and then change 

 to pupse (Fig. 129). The pupae 

 are also active, and they have the 

 anterior end of their bodies greatly 

 enlarged. They eat nothing, and 

 in a few days their skins split open 

 on the back, and the adult mos- 

 quitoes (Fig. 130) come forth. 



In general, the mouth parts of 

 flies are formed for sucking like 

 those of the mosquitoes. Familiar 

 members of this group are the 

 horsefly (Fig. 131), the blowfly, 

 house fly, gnats, midges, etc. 



Flies pass through a complete 

 metamorphosis in their life his- 

 tory. The 



Fig. 128. — Wiggler of com- 

 mon mosquito, enlarged : r, 

 breathing tube. 



egg pro- 

 duces a 

 larva, usu- 

 ally whit- 

 ish in color, without feet. It is called 

 a maggot. When it changes to a 

 pupa, it seldom makes a cocoon; 

 but many transform within the last 

 larval skin which serves as a cocoon. 

 Beetles. — This is the largest group 

 of insects and forms the order, 

 Coleoptera (sheath winged). The 

 beetles possess one pair of thin, mem- 



FiG. 129. — Pupa of com- 

 mon mosquito, much 

 enlarged. 



