Pests and Diseases 



once used by the average man to cover all kinds 

 of plant pests and diseases. The leaflets issued by 

 the Board of Agriculture have been the means of 

 spreading much useful information on this matter, 

 and gardeners will find that every common plant 

 disease is described and the proper treatment set 

 out in these leaflets. 



HOW TO CLASSIFY FOR TREATMENT. 



The figures in brackets after the name of the pest denote 

 the number of the leaflet dealing with the pest. Single copies 

 may be obtained free of charge and post free from the Secretary, 

 The Board of Agriculture 3, St. lames' Square, London, 

 S.W. 



PESTS WHICH WORK ABOVE GROUND, living in 

 most cases on the plants themselves, may be 

 divided for treatment into four groups, viz. : 



(a) Sucking insects, such as the apple sucker (16), 

 aphides (104 and 68), and scale insects (107 and 210). 

 These insects live on the sap oi plants, first piercing 

 the plant tissues and then drawing away the sap. 

 Spraying with fluids, which are usually called " con- 

 tact spraying mixtures," is the proper method for 

 ridding plants of such pests. Paraffin, emulsified with 

 soft soap and water, makes a very cheap and useful 

 insecticide for summer use, and the soap also cleanses 

 the leaves from the excrement of aphides. The 

 plants may be damaged by this wash unless the 

 emulsion is carefully made ; the directions in the 

 Appendix must therefore be carefully followed. 

 (See page 76.) 



Paraffin emulsion is also used to prevent celery 

 flies (35), onion flies (31), and carrot flies (38) from 

 depositing their eggs on the crops, and full particu- 



66 



