550 CALIFORNIA FRUITS: HOW TO GROW THEM 



make 20 gallons. This stock solution will keep for awhile, or in- 

 definitely when protected from the air. 



Preparation of the Spray Mixture with Sulfid of 'Potash. Place 

 10 to 15 pounds of sublimed sulphur, or 14 to 20 pounds of ground 

 sulphur in the spray tank with 4 gallons of flour paste and 1 to 2 

 gallons of the sulfid of potash stock solution ; add water to make 

 100 gallons. For summer or spring spraying after the danger of 

 rains is over, the minimum amount of sulphur is sufficient. 



Winged male. 



Wingless partheno-genetic female. Wingless female. 



Forms of Aphids or Plant Lice. 



Phylloxera. This pest of the grape-vine is closely allied to 

 the aphides, and lives both upon the root and leaf, though in this 

 State the root type prevails and the leaf form is seldom seen. No 

 remedy has yet been found effectual, but escape is had by using 

 roots resisting the insects, as described in Chapter XXVI. The 

 insects are recognized, by the aid of a magnifier, as minute yellow 

 lice, chiefly on the rootlets. Full account of the insect is given in 

 Bulletin 192, University of California Experiment Station. 



