75 



a long, hard, and sometimes discouraging warfare in 1902 against 

 the "hoppers," we demonstrated that they can be effectively, practi- 

 cally, and cheaply controlled. The details of our work will appear 

 in Bulletin No. 215 of the Cornell Experiment Station. 



We finally devised a large, practicable, sticky shield (fig. 1) for 

 catching thousands of the adult "hoppers" in the spring on consid- 

 erable areas. The trouble with many of the previous recommendations 

 for this pest is that they are impracticable or too expensive to operate 

 in large vineyards. We could not get New York vineyardists with 10 

 to 100 acres of vines to use a sticky fan or shingle. We were unable 



Fig. 1. — A practicable, large and efficient sticky shield for capturing 

 spring (from photo by author). 



adult grape leaf-hoppers in the 



to kill many of the adult "hoppers" with a spray or dust of any kind 

 that did not injure the leaves, until we finally tried the cowardly 

 scheme of "hitting them when they were down" with a 25 per cent 

 mechanical mixture of kerosene. We found that a 5 per cent 

 kerosene mixture would not injure the leaves and would bring the 

 "hoppers" to the ground, where they would remain a few moments 

 wiping it off. Continuing this to the end of a row of vines, the pump 

 was set to throw 25 per cent of oil, and going back the same row, this 

 spray was directed at the "hoppers" on the ground. We killed 

 thousands of them in this way, but soon found that none of the 



