NATURE'S CRAFTSMEN 



tion is wholly suspended at the prick of the insect's 

 sting. 



When the enclosed larva has satisfied its appetite it 

 follows the law of its kind, spins about itself a thin 

 swathement, passes into the chrysalis state, and after 

 transformation cuts its way out and begins the cycle 

 of life pursued by endless generations of its forebears. 

 The openings through which the mature wasps escape 

 may often be seen. The blue mud-dauber, Chalyhion 

 (Pelopmis) ccenileum, is wont to place its cells one atop 

 of another in small masses. Sometimes they are found, 

 or the work of kindred species, arranged alongside of 

 one another in extended tubes like ''pipes of Pan." 

 From one such series the author saw emerging a number, 

 of black digger wasps, Trypoxylon politum. That seem- 

 ed proof that the nests had been made by that insect. 

 By no means. This species is reputed by such good 

 authority as Walsh, a guest wasp, not building a nest 

 for itself, but laying its eggs in cells made and provi- 

 sioned by another species. It is curious to trace this 

 use and wont from the guest wasp and the cuckoo, up 

 to the human species as represented by the imperial 

 "annexers" of Europe and the Orient, and the "land- 

 grabbers" of the Indian Territory, not to speak of others 

 of the "guest" habit who may be found nearer home! 

 However, whatever may be the truth as to politum, we 

 know that some of her congeners are most insatiable 

 captors of araneads. 



Spiders are not the only victims of the huntress wasps. 

 Few insects are exempt from their attacks. Some pro- 

 vision their nests with grasshoppers, some with cock- 

 roaches, some with snout beetles, some with apliides, 

 ants, and bees. A great number prefer the two-winged 



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