New York Agricultural Experiment Station. 297 



early habits on" grape vines. 



On migrating to the grape vines, the leaf-hoppers feed first 

 on the lower leaves and shoots. This they may continue to do 

 until the middle of July, although there is a general movement 

 of the insects to the upper portions of the vines as the summer 

 advances and the injured foliage below begins to die. Many 

 eggs are deposited in the lower leaves, but as they become soiled 

 and pitted with many dead areas they cease to be attractive to 

 the insects, either for oviposition or for subsistence. The grape 

 normally produces a quantity of shoots and foliage about its base. 

 As it is considered good practice to remove these during the 

 summer, the injury to such suckers is obviously less important 

 than that to the leaves on canes that are allowed to remain and 

 perform their normal functions for the entire summer. 



The habit of this species to select first the lower portions of the 

 grape vines may perhaps be accounted for by the fact that the 

 under leaves are less subject to disturbance by the wind. Dur- 

 ing a storm the majority of the adults flit to grass or weeds or 

 to dry lumps of earth but when the wind abates they return to 

 their former haunts. A small percentage of the leaf-hoppers 

 nevertheless remain on the vines, and they seem to be able to 

 cling to the leaves even during storms when the wind velocity 

 is high. 



EXPERIMENTS FOR THE CONTROL OF GRAPE 



LEAF-HOPPER. 



Experiments for the control of the grape leaf-hopper were made 

 in a number of vineyards in various portions of the Grape Belt 

 in Chautauqua county during 1912. These were co-operative 

 experiments in which the growers furnished their own material 

 but applied it under the author's direction. All applications 

 were made by means of automatic grape leaf-hopper sprayers.* 



* The automatic grape leaf-hopper sprayer mentioned is described in Geneva 

 Bulletin No. 344, Feb., 1912. No spraying was done by means of trailing 

 hose described in Geneva Bulletin No. 331 because of the successful working 

 of the new attachment. In vineyards located on very steep hillsides, when 

 the rows run across instead of up and down, it will be found difficult to use 

 such an attachment and the trailing hose had better be substituted. 



