

CHAPTER VIII 

 SOME WOOD-BORING WASPS 



Ccrceris finitima Cress. [S. A. Rohwer]. 



This little creature seems, in her behavior, rather para- 

 doxical. We have three records, made in widely different 

 times and places, of finding her digging in sand and entering 

 holes in the ground in a very familiar way. From these 

 observations we had just arrived at the deduction that she is 

 a ground burrower, when we found one in the pith-chamber 

 of a weed-stalk. This was open at the top, where it was 

 broken off, and she was about four inches down. Probably 

 she was preparing to make another cell, since one was al- 

 ready completed. This first one was composed of a layer of 

 mud next to the pith wall, a chamber one-third inch in 

 length containing a pupal case, and another layer of mud 

 for a closing wall. Only ten days later, September 9, this 

 pretty wasp emerged from this cocoon, thereby proving 

 that the mother had been there by no mere accident. Despite 

 the fact that the stem containing the pupa was already split 

 open on one side, the wasp bored a neat hole on the other 

 side by which to gain its exit. 



Since some species of Cerceris use burrowing bees for 

 prey, we may take the liberty of suspecting that she was 

 foraging where we found her peeping into holes in the 

 ground. 



The adults are nectar feeders, fide Robertson and Smith. 



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