HEMIPTERA. 179 



The family has been divided in various ways by different writers. 

 It seems best to recognize in this place only two sub-families ; although 

 seven are proposed by Stal. These two sub-families can be distin- 

 guished as follows: 



A. Ocelli placed on the front rim of the vertex close to the eyes, or on the 



front, but never on the disk of the vertex. I. jASSlNiE. 



AA. Ocelli placed upon the vertex. II. Tettigoxin.k. 



Sub- Family I.— J ASS IX. k. 



The more important members of the Jassinae from an economic 

 standpoint are the following: 



The Destructive Leaf-hopper, Cicadula exitiosa. — During the 

 winter of 1879-80 much damage was done to winter grain in the 

 Carolinas and Georgia by this species. It is a small, active, brownish 

 insect, which measures with its wings folded about 5 mm. (0.2 inch) in 

 length. Its general form is well indicated by the enlarged figure (Fig. 

 148). It is very quick, a good flyer, and a great jumper. 

 It injures grass or grain by piercing the midrib of the 

 leaf and sucking the juices from it. Upon the planta- 

 tion where I studied this insect there was observable a 

 most exact line between the eaten and uneaten portions of 

 the wheat-field. Instead of spreading themselves over 

 the field indiscriminately, or half eating a patch here and 

 there, the leaf-hoppers ate the wheat down to the ground M 

 as they progressed. They are very shy, however, and fly FlG m8 _ 

 away on the least disturbance. Judging from the known exlf/'J*. 

 habits of allied species, the eggs are doubtless laid in the A^tho'r's 

 stems of grasses close to the ground. The young hoppers iSyg )' 1 

 when hatched are almost precisely of the same appearance 

 as the old ones, except that they lack wings. The time occupied in 

 attaining full growth probably does not exceed a month, so that 

 there are several broods a year. These insects are readily attracted 

 by light; and probably many of them could be destroyed by trap- 

 lanterns, or by building bonfires at night. It is possible, also, that 

 many could be destroyed by spraying with some of the alkaline or 

 other washes described in the chapter on remedies. In those cases 

 where the line of injury is a well-marked one, only a small part of 

 the field would need to be sprayed. 



The Grape-vine Leaf-hopper, Erythroneura litis. — There are 



