Introduction 



By 



Karl V. Krombein, 



Paul D. Hurd, Jr., 



and 



David R. Smith 



This catalog, which is an outgrowth of the 

 highly successful Hymenoptera of America 

 North of Mexico Synoptic Catalog (1951), 

 including the first and second supplements 

 (1958, 1967), provides simultaneously, by 

 use of computer technology (Krombein, Mello 

 and Crockett, 1974. Ent. Soc. Amer., Ann. 

 20 :24-29), a printed version as well as a 

 computer-queriable data base of the basic 

 systematic, biological, and morphological in- 

 formation on the order Hymenoptera as it 

 occurs in America north of Mexico. While the 

 format of the present catalog closely parallels 

 that of the original catalog, every effort has 

 been made to increase the information con- 

 tent to fulfill better the needs of the biological 

 community. This has been accomplished chief- 

 ly by the introduction of textbook prose at 

 most higher category levels, by the presenta- 

 tion of explanatory or descriptive comments 

 as appropriate, and by the inclusion of more 

 complete listings of citations to taxonomic, 

 biological, and morphological literature at all 

 hierarchical levels together with parentheti- 

 cal annotations concerning the content for 

 many of these citations. Similarly, the data 

 about hosts, parasites, prey, predators, and 

 pollen sources are covered more fully than in 

 the original catalog. Since these data have 

 been reported in various ways and under dif- 

 fering names in the primary literature, an 



attempt has been made to organize this in- 

 formation and present it, usually, alphabeti- 

 cally even though sometimes such data have 

 been recorded in the literature with scien- 

 tific or vernacular names or both. Although 

 many of these names have been checked for 

 accuracy, no consistent attempt has been 

 made to verify that the names agree with 

 current usage or status. While those authors 

 of zoological names are usually abbreviated 

 in the citation of hosts, parasites, and the 

 like, the authors of the scientific botanical 

 names are not included. Elsewhere in the 

 catalog, the last name of an author is cited 

 in full, but without initials. Since the tech- 

 nology employed in the preparation of this 

 catalog precluded the use of diacritical marks, 

 these have been omitted and consequently, 

 as in the case of the umlaut, a variant spell- 

 ing has been substituted as appropriate. 



The International Code of Zoological No- 

 menclature (1961) including the intent and 

 preamble of the Code and of any pertinent 

 opinions usually has been followed. Thus a 

 name in current usage as deterimned by the 

 code is employed, but mention is made, as 

 appropriate, that an application is pending 

 before the International Commission of 

 Zoological Nomenclature. 



An attempt has been made to record all the 

 recent taxa, with their synonyms, described 



Vlll 



