CHAPTER VI 



FRUIT PESTS AND ENEMIES 



The proverb, "That evil is half cured whose cause we know," 



furnishes a text for opening the discussion of the pests of the orchard. 



The subject is much simplified by a classification 



Orchard qJ orchard insects and diseases. These fall into 



Classified three general types — insects, fungous diseases, and 



bacterial troubles. 



Insects, in their turn, are divided into those which chew and 



those which suck. Chewing insects — caterpillars, worms, and beetles 



— are killed by poisons taken internally, of which arsenate of lead is 



now sovereign of all. Sap-thirsty 

 insects — the myriads of plant- 

 lice and scales — are destroyed by 

 caustic applications, of which 

 the lime-sulphur mixture is now 

 most used. 



Fungous diseases, more diverse 

 than the plants they grow on, 

 for every plant has several or 

 many, can be but roughly char- 

 acterized by the damage they 

 do. Usually a fungous disease 

 shows in definite spots on leaf, 

 fruit, or branch. Affected leaves 

 and fruits often drop from the 

 tree. Examples are apple-scab, 

 the leaf-blights, black-knot, the 

 mildews, and rots. Treatment is 

 preventive and consists of cover- 

 ing the plant with some fungi- 

 cidal mixture wliich stops the 

 fungus from obtaining an en- 

 trance into the tissues of the host 

 plant. Lime-sulphur and bor- 

 deaux mixture are the best two 

 fungicides. 



Bacterial diseases are the 

 S4 



A portalJc kiiap.s;irk spiaj-ur slioulil be 

 pa,rt of the equipment of every home 

 garden. 



