PESTS AND DISEASES OF PLANTS 233 



Red Spider of Almonds. Spray with lime-sulphur, using very 

 weak solution, say about 1-33, or sulphur thoroughly. 



Crown Gall. If young trees, dig up and burn; if older, treat with 

 Bordeaux paste, chiseling down to healthy wood. 



Dieback. A physical disturbance caused by unnatural soil con- 

 ditions. 



Walnut Blight. Sprays ineffective. The only treatment is preven- 

 tion by using resistents. 



Grape. 



Grape Phylloxera. Attack roots and foliage of the vines. Plant 

 resistent stock. Be sure of your nursery stock. 



Vine Hopper. Infests foliage of the vines. Use hopper-doser in 

 spring before adult females deposit their eggs. Spray as soon as the 

 young begin to appear with distillate emulsion. 



Grasshoppers Use poison baits. 



California Root Worm. A black beetle whose larvae attack the 

 leaves, stems, petioles, roots and fruit of the vines. Cultivate deeply 

 around the base of the vines. Spray with lead arsenate as soon as 

 beetles appear. 



Flea Beetle. It infests the foliage and may be handled by spraying 

 liberally with lead arsenate. 



Hawk Moth. The large green larvae of this moth feed upon the 

 foliage. Hand pick, or if too numerous spray with lead arsenate. 



Grape Leaf Folder. The larvae roll themselves up in the leaves, 

 which they eat. Spray with lead arsenate. 



Erinose. This so-called disease is produced by a small mite, 

 which is characterized by forming swellings upon the upper surfaces 

 of the leaves. Dust plants liberally with sulphur when they are wet 

 with dew. 



Nematode Root Gall. A minute worm attacking the small roots. 

 Destroy all infested vines. Sterilize soil with carbon bisulphide. 

 Plant only hardy varieties where this exists. 



Powdery Mildew. Grows upon the canes, leaves and fruit. Dust 

 often with sulphur as soon as the disease appears. Spray early with 

 Bordeaux. 



Downy Mildew. Attacks all green portions of the plant leaves, 

 young shoots and berries. Spray with weak Bordeaux as soon as 

 first appearance is made. 



Blackberries, Raspberries, Loganberries, Strawberries. 



Rose Scale. A white scale thickly infesting the canes just above 

 the surface of the ground. Spray with lime-sulphur or kerosene 

 emulsion. 



San Jose Scale. A small scale badly infesting the canes, particu- 

 larly of the raspberry. Spray with lime-sulphur. 



