no. 2173. A REVISION OF THE BEMBICINE WASPS— PARKER. 131 



adult between July 10 and September 2 — a period of 54 days. In 

 both cases the emerging wasps were females. It follows from this 

 that in this locality Bembix spinolae has more than a single brood each 

 year. I may add here that the wasps were still active in the field 

 after September 2. 



The prey of spinolae, as in the case of other species of Bembix, con- 

 sists of flies. The species found in greatest numbers in the nests 

 opened in the course of my investigations was the common house- 

 fly, due perhaps to the fact that the nesting site was located in a 

 suburb in the city where this fly could be most easily obtained. 

 Some individuals, however, showed a preference for other species, 

 and not a single nest was fomid in which the flies were all of one spe- 

 cies. Below are given the contents of three different nests, each of 

 which contained a larva that I judged to be four or five days old. 

 The flies found in these nests were kindly determined for me by 

 Mr. W. R. Walton. 



First nest. 



2 Winthemia 4-pustulata Fabricius. 

 10 Pseudopyrellia cornueinia Fabricius. 



1 Musca domestica Linnaeus. 



2 Sarcophaga, species ? 



Second nest. 



1 Chrysops pudicus Osten Sacken. 



1 Chrysops niger Macquart. 



2 Tabanus coffecatus Macquart. 

 16 Odontomyia virgo Wied. 



Third nest. 



1 Chrysops lugeus Wied. 



2 Chrysops pudicus Osten Sacken. 

 1 Tabanus pumilus Macquart. 



1 Tabanus lasiopthalmus Macquart. 



13 Odontomyia virgo Wied. , 



BEMBIX BELFRAGEI Cresson. 



All investigators that have observed the habits of species of 

 Bembix report that these wasps provision their nests exclusively with 

 dipterous insects. I know of but one exception to this: Hartman 

 in Observations on the Habits of Some Solitary Wasps of Texas, 

 page 32, reports Bembix belfragei Cresson as provisioning her nest 

 with a large species of bug, a hemipterous insect. He informs me 

 that the specimens on which this observation was based can not now 

 be located. I am strongly of the opinion that identification in this 

 case has been incorrect; that the species reported upon has been a 

 member of the genus Bicyrtes. This is, however, only a matter of 

 opinion based on a limited experience with species of the two genera. 

 If B. belfragei does provision her nest with hemipterous insects she 

 forms a marked exception among the species of Bembix thus far 



