UNITED STATES NATIONAL MUSEUM BULLETIN 224 



Comprehensive bibliographies in all fields of entomol- 

 ogy are scarce and much to be desired. In Diptera the 

 fine bibliographies of Bequaert (1953) on Hippobos- 

 cidae, and of Henning (1952) are superior to any I 

 have ever worked with. Crampton (1942) gives 356 

 references in a bibliography of Diptera morphology. 

 In this work the bibliography of the Asilidae ends with 

 the year 1954, except that references I have been able 

 to obtain for the years 1955-1960 are included. 



The species list, which has been included with the 

 genera and subgenera, is offered as a practical and im- 

 mediate aid for the encouragement of students, new 

 and old alike. In the preparation of these species lists 

 I have followed Kertesz (1909) in his world catalog 

 of Diptera, except that for Europe I have adopted al- 

 most entirely the disposition of Palaearctic species as 

 given by Engel (1925-30). For the United States 

 most asilid species are well known, except those of the 

 genus Asilus Linne, which require additional study. 

 The scope of this study of genera has not permitted 

 a review of the more than 4,700 species in order to 

 substantiate their generic location. Where I have 

 been privileged to see specimens of species, I have used 

 the information acquired to assign them to a proper 

 place according to the concepts of this study; other- 

 wise not. The Asilidae of Europe and North America 

 above Mexico are rather well known, but many of the 

 species of older authors, especially Macquart and 

 Wiedemann and others remain but poorly known and 

 require new study in the light of present day generic 

 concepts. This is especially true of Asilus Linne 

 Dasypogon Meigen, and Laphria Meigen. The check- 

 list of the species of Asilidae ends with 1954, except 

 those of Wilcox and Martin, and Hull through 1958. 



I have adopted much but not all the synonymy indi- 

 cated or suggested by Eicardo in her valuable series of 

 papers; I have done so particularly in those cases 

 where she has had access to the Walker and Bigot 

 types. Eicardo also made several trips to see the 

 Macquart types. And for the same reason I have 

 accepted the synonymy given by G. H. Hardy where he 

 has stated that he has seen the types. Perhaps this 

 is an appropriate place to call attention to the state- 

 ment of Collin (1933), who in his study of the Diptera 

 of Patagonia and South Chile notes that Empis cotox- 

 anthus Blanchard is certainly not an empidid. Collin 

 suggests that it may belong to the family Asilidae; it 

 should prove most interesting to students of this 

 family. 



This work attempts to furnish the minimum ade- 

 quate illustrations for each genus. Past publications 

 on the family Asilidae have provided, in rather scat- 

 tered places, more than 3,781 figures of asilids or parts 

 thereof. This figure represents a tally for only those 

 papers that give an exact count and have been used 

 by me; I am sure that the number would be greater if 

 all scattered and occasional illustrations were included. 

 Many of these illustrations are excellent, but some are 



too small to be effective and useful. I wish to call 

 especial attention to the 305 figures of Melin (1923) ; 

 the 384 figures in Seguy (1927); the 210 figures in 

 Carrera (1949) ; the 284 figures of Engel in Lindner; 

 besides the 352 text figures and 82 superb, colored, whole 

 figures of the late H^C. Efflatoun (1937). 



Every student of taxonomy builds on the work of 

 others. I wish to pay especial tribute to the fine work 

 of the late Dr. Stanley Bromley in the United States 

 and to Dr. Friedrich Hermann in Germany. Her- 

 mann proposed 48 genera. Attention must also be 

 called to the signal contribution of Melin (1923), 

 whose monumental and painstaking work on the mor- 

 phology of immature stages and the behavior of asilids 

 is our best study on this aspect of these Diptera. 



Relationships and Phylogeny 



The study of ancestral relationships of the several 

 families included among the Brachycera is filled with 

 difficulty. As Cazier (1941) and others have pointed 

 out, in any study of phylogeny it is essential that the 

 most fundamental characters, those least likely to be 

 affected by adaptive specializations, be utilized for 

 understanding relationships. The author takes the 

 view that when the relative value of the wings, the legs, 

 the mouthparts, the antennae and the terminalia are 

 considered, the wings and terminalia are least likely to 

 be affected by adaptive changes. The terminalia, of 

 course, do show some adaptive changes centering 

 around both mating and egg deposition. Provided a 

 wing has sufficient number of veins to support its re- 

 sistance to air, it is not likely to change, except as a 

 progression. The wing is, then, in many instances, 

 likely to be a true indication of relationships. How- 

 ever, parallelisms arise also in wing venation. Com- 

 parison of fossil asilids shows how little change has 

 taken place in wing venation. It is interesting that 

 those families with the most constant activity and of 

 larger size have the most veins in supporting the wing 

 membrane. For example, Mydaidae may be quite 

 large, and they undoubtedly are decadent, but they are 

 agile and excellent fliers. The bombyliids and the 

 asilids put even greater demands on their respective 

 wings and their veins are stout, numerous and the wing 

 rather well subdivided. 



In searching for indications of common relationship, 

 the dipterist cannot fail to be impressed by the general 

 similarity of the wing of the rhagionid, the therevid, 

 the tabanid and such lower members of the asilids as 

 have all marginal, posterior, and anal cells open. The 

 asilids, apioceratids, therevids, and mydaids appear 

 to form a natural group. In this work, the Asilidae 

 are considered to have a position off to themselves, but 

 more closely related to the apioceratids than to the 

 mydaids. The asilids are set apart by the presence of 

 the simple, bristlelike empodium. In most of the other 

 families of Brachycera, the pretarsus is characterized 



