CONTROL OF IXSECTS IX.TURIOUS TO THE GRAPE 1307 



the middle of September. 1'sually only one brood is produced 

 each season. The leaf-hoppers which become adults during the 

 latter part of July or later feed on the foliage until autumn and 

 then seek winter quarters. 



The only stage of the grape leaf-hopper known to pass the 

 winter in this state is the adult. They seek fallen leaves and 

 grass which has lodged, and under such protection pass the winter 

 (Fig. 448). It is necessary that such places be comparatively dry 

 and free from inundation if the insects are to survive. It is for 

 this reason that we find sandy ridges and knolls most favored by 

 them. Emergence from hibernation occurs during the warm days 

 of spring, after which the leaf-hoppers seek their food plants. 

 I'IMHI these they remain until the foliage of the grape has ex- 

 panded, when they migrate to this, mate, lay their eggs, and die. 



FIG. 448. CONDITIONS FAVORABLE FOR THE HIBERNATING OF GRAPE 



LEAF-HOPPERS 



Control 



Two methods of control are effective against the grape leaf- 

 hopper: (l)spraying with i contact insecticides; (2) destruction of 

 the hibernating places. The only spray that is effective is one 



