64 INSECTS AFFECTING THE PLUM. 



pests. The leaves of many varieties of plums are 

 easily injured by the arsenites, so that much care 

 should be taken in spraying, not to use too strong a 

 mixture, nor to get too much on the tree. Paris 

 green is preferable to London purple for this pur- 

 pose, when tender classes of fruits are to be operated 

 upon. In using Paris green the mixture must be 

 frequently stirred to make sure that the poison does 

 not settle to the bottom of the vessel and thus ren- 

 der the applications of unequal strengths. It is 

 well after each barrel of liquid is used to draw off 

 all the residue in the bottom. 



If the aphides or plant-lice become too numerous 

 in spring, spray with kerosene emulsion. 



