THE LEAF-HOPPERS 



(Family Jassidce.) 



This group of insects, which comprises the forms ordinarily 

 known as leaf-hoppers, is an extensive group, comprising a 

 great complexity of forms and by most modern 

 writers is considered as having superfamily rank 

 and is generally termed " Jassoidea." They are 

 usually slender insects, with the antennae in- 

 serted in front of and between the eyes and 

 having the hind tibiae with a row of spines be- 

 low. They 



Fig. 137. — Proco- 

 nia undata. (From 

 U. S. Dept. Agr.J 



are very 

 abundant 

 on low- 



growing 

 herbage and have been 

 shown by Professor Her- 

 bert Osborn to bring about 

 a very extensive although 

 probably unnoticed injury 

 to forage plants in large 

 grazing ranges in the 

 west as well as in pasture 

 lots in the east. He shows 

 that on an acre of pasture 

 land there frequently exists 

 one million leaf-hoppers and 

 that this million hoppers 

 consume as much grass as 

 a cow if not more. In this 

 restricted sense this family 

 includes the leaf-hoppers 

 now generally placed in the 

 family Tettigonidae which 



JK 



a 



Fig. 138. — Thamnotettix clittelfarius. 

 (After Lugger.) 



243 



