HEMIPTERA 



63 



some members of the species with us every 

 summer. The males in this family pos- 

 sess, at the base of the abdomen, two 

 drum-like organs with which they produce 

 their characteristic song or " shrill. " 

 Cicadas are, as a rule, harmless, but the 

 periodical cicada does great injury to fruit 

 trees by splitting the twigs to deposit its 

 eggs. Fortunately it does not come often 

 enough to be a serious menace to the 

 fruit industry. 



Plant-hoppers. Several families of ho- 

 mopterous insects constitute a group gen- 

 erally spoken of collectively as the plant- 

 hoppers. Broadly speaking, we may in- 

 clude in this group the Spittle insects (Cer- 

 copidce), forms which, in young stages, live 

 concealed in a frothy secretion which 

 resembles spittle, and are found on several 

 common weeds; the Lantern-flies (Fulgori- 

 dce), among which are a few moth-like 

 forms and, in the tropics, some others 

 that are luminescent, but which do not 

 include our fire-flies; and the more impor- 

 tant and numerous Leaf-hoppers (Jassidce\ 

 and Tree-hoppers (Membracidce) . All of these 

 families have the power of leaping but 

 they are otherwise sufficiently distinct for 

 easy recognition. The Jassidce are slender, 

 small, and have pointed heads. The tree- 

 hoppers are stouter bodied, larger and have 

 heads nearly concealed beneath the protho- 

 rax when seen from above, and usually cut 



2. 



4. 



6. 



9. 



FIG. 38. Types 

 of Homoptera. 

 Slightly en- 

 larged. 



1, 6, Leaf-hop- 

 pers (Jassidae) ; 2, 

 8, Cercopidce; 3, 4, 

 Tree -hoppers 

 (M embracidce) ; 5, 9, 

 FulgoridcB; 7, Plant- 

 louse (Aphididce). 



