CHAPTER XV 



FOES AND FRIENDS OF THE PLANT 1 



EVERYONE who grows plants must fight against the 

 hungry insects which are eager to eat them. But by 

 knowing jusj how to apply the proper remedies, insects 

 may be almost entirely prevented from harming our 

 plants. 



Some insects^ eat^the leaves. They may be poisoned 

 by spraying with lead arsenate or Paris green. Direc- 

 tions for making sprays are given on page 412. The 

 leaves should be covered with fine drops like dew. 

 Unless Paris green is properly made, it injures the leaves. 

 A certificate from the State University is required for 

 Paris green sold in California, and no one should buy 

 it without seeing this certificate. 



Some insects suck the juices from leaves by thrusting 

 their beaks into them. These sucking insects are not 

 injure^Lby lead arsenat^ because it stays on the outside 

 of the leaf, and they take their food from the inside. 

 We must therefore spray the insects rather than the 



1 The teacher is especially advised to take up only a few typical 

 forms, which can easily be obtained in his locality, for illustra- 

 tion. 



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