Nearctic Wasps 



of the 



Subfamilies Pepsinae and Ceropalinae 



Introduction 



The family Psammocharidae includes a large number of common 

 wasps that provision their nests with spiders. Typical psammochar- 

 ids are long-legged insects commonly seen on flowers or running rap- 

 idly over the ground or low vegetation, often nervously flipping their 

 wings. A large portion of the Nearctic species are black with black 

 wings, though various members of the family are marked or colored 

 with red, orange, yellow, white, or metallic blue. Technically, the 

 psammocharids may be distinguished from all other wasps by a straight 

 transverse groove that divides the mesopleuron into upper and lower 

 halves (figure 1,6). This groove is always present, and though other 

 wasps possess grooves on the mesopleuron, none but the psammo- 

 charids have one that is single, straight, and transverse. The species 

 included in the present paper are those belonging to the subfamilies 

 Pepsinae and Ceropalinae, occurring in America north of Mexico. 



Previous taxonomic work on these species, except for two papers on 

 Pepsis by Hurd, is not outstanding and consists largely of the descrip- 

 tion of new species. References to all the original descriptions are 

 given in the species headings, the significant papers dealing with 

 biology are cited in the synonymy of the species concerned, and the 

 few revisional papers may be located by referring to a recent cata- 

 logue (Townes and Hm'd, 1951, U. S. Dep. Agr., Agr. Monogr. No. 2, 

 pp. 907-973). In addition to this Uterature are numerous locaUty 

 records (largely in state lists), some notes on synonymy and taxon- 

 omj^ and the well known lectotype lists by Cresson (t>T)es in the 

 Academy of Natural Sciences of Philadelphia) and by Rohwer and 

 Gahan (Provancher types). The specimens which form the bases for 

 most of this literature have been restudied and re-recorded accord- 

 ing to the taxonomy in this paper. No attempt has been made to 

 correct the many errors of identification that occur in literature, but if a 

 record in literature is not repeated in the summary of the distribu- 

 tional and biological data from pin labels on the specimens studied, 



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