114 



ORDER HEMIPTERA 



duction from the West Indies or Mexico in some not distant 

 period. 



Six-spotted Leafhopper. — The six-spotted leafhopper occurs 

 in abundance throughout the country and is also a common 

 species in Europe. Whether its common distribution is due 

 •to original extent of the species, or whether the species has 

 been introduced into America in modern times, is impossible 

 to say. It develops rather rapidly and apparently passes 

 through two or three generations at least in northern locali- 

 ties, and possibly three to five in the more southern States. 

 It is especially injurious in oat fields. 



Fig. 70. — The six-spotted leafhopper {Cicadula-6-nolata): a, adult; 

 b, face; c, wing; d, female genitalia; e. male genitalia; /, nymph. All 

 enlarged. (After Osborn, Bull. 108, Bur. Ent., U. S. Dept. Ag.) 



Typhlocybidse includes a group of minute forms most of 

 which are found on trees or woody plants, but certain ones 

 occur on grains or grasses. The most familiar and destruc- 

 tive forms are the group of leafhoppers which cause wither- 

 ing and whitening of grape-vines in the midsummer and 

 autumn. Typhlocyha comes includes several varieties, all 

 of which are destructive to grapes, the nymphal stages 

 being found usually on the under side of the leaves, and the 

 effect of their puncturing shows in minute white spots on 

 the upper surface of the leaves. 



