mXRODUCTION 



A number of years ago at the suggestion of Profs. Lawrence 

 Bruner and Myron H. Swenk I undertook to determine the material 

 in the family Mutillidae at the University of Nebraska, I had not 

 progressed very far with that work before it was evident that the 

 existing literature was inadequate for the identification of many of 

 the species and that the North American Mutillidae presented a rich 

 and interesting field for study. My interest was further aroused 

 when I found upon examination of the genitalia of the males that 

 these structures might be of considerable aid in the classification and 

 identification of the males. AVhen I succeeded in identifying five or 

 six different species of male Dasynvutilld from a series which had 

 been considered as one variable species by previous workers consid- 

 erable doubt arose in my mind as to whether the statements in the 

 literature regarding the great amount of individual variation exist- 

 ing in this family were true. So I began the study, which has out- 

 grown my original plan and which has resulted in the paper pre- 

 sented herewith. The conviction that the biology of insects is as 

 much a factor in their taxonomy and phylogeny as morphology led 

 me to assemble all the knowledge regarding their biology and to 

 carry on some minor researches of my own, both of which are 

 included in part 1. In accomplishing this I have examined practi- 

 cally all of the 630 entries listed in the bibliography, most of them 

 in the original. At the suggestion of Mr. S. A. Rohwer, I under- 

 took a study of the genotypes of the family, and the results of that 

 study are found in part 2. I believe that a taxonomic study to be 

 at all complete, should be based on a quantitative study, and I there- 

 fore assembled approximately 10,000 specimens of the genus Dasy- 

 mutilla for the basis of the work presented in part 3. Through the 

 hearty cooperation of many individuals, acknowledged below, the 

 material in almost all the important insect collections of the United 

 States and Canada has been included in the study. 



In this part of the work I have included keys for the identifica- 

 tion of the males and females, a complete bibliographic history of 

 each species, information regarding the location of the type speci- 

 mens of each species, a summary of the geographic distribution of 

 each species which in the case of the commoner species includes an 

 outline map illustrating this, a complete record of the locality, date, 

 and collector on each specimen, and notes regarding the salient char- 



