26 SCHOOL ENTOMOLOGY 



D. Parasitic upon man or warm-blooded animals. 



E. Hind legs fitted for jumping. Fleas. Siphonap- 



tera. 

 EE. Hind legs not fitted for jumping. 



F. Beak, fleshy, unjoin ted. True lice. Siphun- 



culata. 

 FF. Beak jointed. 



G. Tick-like forms, parasitic. Sheep tick, 



etc. Diptera. 



GG. Not tick-like. Bedbugs. Hemiptera. 

 DD. Not parasitic; generally found on living plants. 

 Plant lice, scale insects, etc. Hemiptera (Homop- 

 tera) . 

 AA. Winged insects. 



B. With two wings. 



C. With sucking mouth-parts. Diptera. 

 CC. Mouth-parts not for sucking. 

 D. Rudimentary mouth-parts. 



E. Size almost microscopic, halteres present. 



Males of Coccidce. Hemiptera. 

 EE. Size larger, no halteres. Ephemerida. 

 DD. Biting mouth-parts. 



E. Wings hard and horny. Coleoptera. 

 EE. Wings flexible, many veins. Orthoptera. 

 BB. With four wings. 



C. Mouth-parts for sucking. 



D. Wings covered with scale-like hairs. Lepidop- 



tera. 



DD. Wings not covered with scale-like hairs. Hem- 

 iptera. 



CC. Mouth-parts not for sucking. 

 D. Wings equal. 



E. Bodies very long and slender. Wings narrow. 

 F Antennae inconspicuous. Dragon-flies, etc. 



Odonata. 

 FF. Antenna prominent. Ant-lions, etc. Neu- 



roptera. 

 EE. Bodies shorter. 



F. Wings with few veins. 



