THE ENEMIES OF PLANT LIFE 



would then ship it back again, the eggs to be 

 hatched out in San Francisco and the foe 

 liberated wherever the pest appeared. 



Strangely enough, so far as now known, 

 each foe must have its particular parasite or 

 pest to feed upon. It is said, for example, that 

 the tiny ladybird that saved the orange and 

 lemon orchards by destroying the cottony 

 cushion scale will starve to death on any other 

 food than the scale; it would seem that it 

 has been specially prepared for this particular 

 act of destruction. 



In order to prevent further introduction of 

 pests, the state of California has established a 

 rigid quarantine against foreign ports in order 

 that no new pests may be introduced. Among 

 the pests which are common, and which the 

 commission is preparing for by keeping up 

 a constant search for their natural foes, are 

 the following: Plant-lice, prune-aphis, woolly 

 aphis, black peach-aphis, cabbage-louse, grape- 

 louse, pear-scale, red scale, peach-root borer, 

 peach - moth, canker - worm, tent - caterpillar, 

 cherry-slug, Harlequin cabbage-bug, box elder 

 plant-bug, Fuller's rose-beetle, various types 

 of thrips, red spiders and mites of various 



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