86 



THE APPLE LEAF HOPPER 



whicli this leaf was taken had been sprayed over four weeks pre- 

 vious to the taking of the photograph, and during this period the 

 rainfall had been very heavy. At the time the picture was made 

 three leaves were examined and analyzed by the Chemical Division 

 of the Experiment Station, and traces of arsenic were still fovind. 

 In this connection it is interesting to note that in another experi- 

 ment where Paris green was used, handfuls of leaves were ex- 

 amined, and not a trace of arsenic was found. 



Fig. 34. Plum leaf showing adliesive qualities of arsenate of lead. Original. 



The season of 1907 arsenate of lead at the rate of three pounds 

 to fifty gallons of water was used. The first spraying w^as given 

 just as the buds were bursting, namely, May 29th ; the second 

 spraying was done on June 17th, after the blossoms had fallen and 

 young plums were the size of small peas. The third spraying w^as 

 on June 24th. 



