THE ENEMIES OF PLANT LIFE 



report from any region of the state that this 

 pest is appearing, a colony is sent out by the 

 first mail, and soon the balance is restored. 

 Supplies of the infested twigs and branches 

 are gathered along in May. This foe is differ- 

 ent from the ladybird in its method of attack, 

 eating its way into the parasite or pest instead 

 of killing it from the outside. The twigs are 

 placed in wooden boxes, in the sides of which 

 are glass vials. The foe at last emerges from 

 the insect in the box and goes out into the 

 vial. As soon as twenty-five, or more, have 

 crawled out into the vials, the mouths of the 

 vials are closed up with cotton, to prevent the 

 escape of the flies and yet give them air, the 

 vials are placed in stout pasteboard tubes, and 

 thus are mailed to the orchard growers where 

 the pest appears. Colony after colony is thus 

 secured. Tens of thousands of them are sent 

 out, and they do their work swiftly and well. 

 These foe insects do not in themselves do 

 harm. Their chief object is to find their nat- 

 ural enemy, which is the enemy of the fruits. 

 The pest may never be wholly destroyed in 

 a given region, but, by the introduction of its 

 foe and the consequent preservation of the 



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