THE NEW EARTH 



A small supply of the pupae of the flies was 

 secured and dispatched to San Francisco. In 

 the insectary of the California Horticultural 

 Commission located in that city, they were 

 hatched out into a small colony of the flies. 

 They were supplied with pieces of branches of 

 apple trees bearing the worms. Instantly on 

 discovering the worms they began their work 

 of destruction. The stiletto is so powerful that 

 it can be driven down into the bark when the 

 worm is under the surface, the insect unerr- 

 ingly locating the worm. It finds the worm, 

 kills it, and then lays a few of its many eggs 

 upon the worm's body. Curiously enough, the 

 natural warmth in the body of the worm is 

 sufficient to hatch out the eggs, the hatching 

 requiring but two hours' time. The worm thus 

 serves as the hotel, so to speak, for the young 

 flies. They live on and in it until they are 

 ready to take up their life-work. When they 

 have reached forty-two or forty-three days of 

 age, they are ready to begin their actual work 

 of destruction. As each female lays several 

 hundred eggs, the rate of progression, where 

 there is ample material on which to feed, is 

 very great. 



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