HOW TO KNOW THE IMMATURE INSECTS 



8b. Tracheal gills, usually iinger-like bunches or single, often located 

 on the ventral aspect of the thoracic segments; in some cases they 

 occur on the jaw, on the proximal and the last segments of the 

 abdomen; (may be absent in Nemouridae and Capniidae); 2 dis- 

 tinct tails (cerci), usually without long fringes of setae, occur at 

 the caudal end of the abdomen; tarsi possesses 2 claws. 

 Fig. 58 Order PLECOPTERA page 59 



The stoneflies constitute a small order, about 

 1,500 species being described. The naiads are 

 aquatic, they live under debris in eddies or un- 

 der stones in clear fresh water and feed largely 

 upon the larvae of Mayflies and midges, but 

 some are thought to feed upon vegetable de- 

 bris. The time occupied in development appears 

 to range from about a year to four years. 



Fig. 58. Topoperia 

 media (Walker). - 



9a. Antennae not more than 5-segmented; body strongly depressed; 

 head larger and broader than prothorax; ectoparasitic life. 

 Fig. 59 Order MALLOPHAGA 



The biting lice or bird lice are 

 ectoparasites of birds and mam- 

 mals. About 2,800 species have 

 been described. Their food con- 

 sists of dry and nearly or quite 

 dead cuticular substances. Eggs 

 are glued separately to the feath- 

 ers or hair. The nymphs closely 

 resemble their adults except in 

 size. The distribution of the biting 

 lice is quite limited to their defin- 

 ite hosts. 



Fig. 59. a, Variable hen louse, Lipeurus 

 caponis (L.) (Ohio Agr. Expt. Sta.); b. 

 Large chicken louse, Goniocotes gigas 

 (Taschenberg) (Ohio Expt. Sta.). 



9b. Antennae more than 5-segmented. 



10 



10a. Prothorax usually subequal to mesothorax or larger; if prothorax 

 is much smaller than mesothorax then cerci are present, tarsi are 

 5-segmented and the legs are greatly elongated 11 



34 



