INTRODUCTION^ IX 



send me a transcript of Scholz's paper entitled " Bienenfeinde." Dr. 

 R. N. Chapman, chief of the division of entomology, University of 

 Minnesota, is responsible for securing the aid of Miss Margaret 

 FuUeylove, who has sent me transcripts of a number of papers from 

 the entomological libraries of England. 



Dr. J. Chester Bradley generousl}^ turned over to me the valuable 

 collection of Dasyniutilla at Cornell University, together with notes 

 on a number of new species. Dr. A. L. Melander was kind enough to 

 loan me the types of species described by him. 



The following persons and institutions have assisted me by the loan 

 of material : Mr. S. A. Rohwer, United States National Museum ; Dr. 

 F. E. Lutz, American Museum of Natural History; Dr. Nathan 

 Banks, Museum of Comparative Zoology; Dr. Henry Skinner and 

 Mr. E. T. Cresson, jr., American Entomological Society; Dr. J, 

 McDunnough and Mr. C. Howard Curran, Canadian Department of 

 Agriculture; Dr. J. C. Bradley, Cornell University; Prof. S. J. 

 Hunter and Dr. H. B. Hungerford, University of Kansas; Prof. 

 Myron H. Swenk, University of Nebraska; Prof. F. M. Gaige, 

 University of Michigan; Prof. J. J. Davis, Purdue University; Dr. 

 H. H. Knight, Iowa State College; Prof. George A. Dean, Kansas 

 State Agricultural College ; Dr. C. P. Gillette, Colorado State Agri- 

 cultural College; Dr. Paul Gilmer, New Mexico State Agricultural 

 College; Prof. T. D. A. Cockerell, University of Colorado; H. A. 

 ScuUen, Oregon Agricultural College; Prof. J. R. Parker, Montana 

 Agricultural College ; Prof. H. J. Reinhard, Texas Agricultural Ex- 

 periment Station; Prof. M. R. Smith, Mississippi Agricultural and 

 Mechanical College; Dr. H. P. Severin, South Dakota Agricultural 

 College; Mr. J, G. Sanders, Pennsylvania Department of Agricul- 

 ture; Mr. H. S. Smith, California State insectary; Mr. D. C. Mote, 

 State entomologist of Arizona ; Prof. G. M. Bentle}^, Tennessee Agri- 

 cultural College; Clemson College, South Carolina; Utah Agricul- 

 tural College; North Carolina Department of Agriculture; Leland 

 Stanford University; Prof. H. F. Wickham; Dr. J. Bequaert; Mr. 

 W. E. Hoffmann; Prof. O. A. Stevens; Mr. C. N. Ainslie; Mr. A. A. 

 Nichol; Mr. G. W. Goldsmith; Mr. W. Knaus; Dr. E. G. Anderson; 

 Mr. Arthur Harris, jr.; Mr. L. S. Slevin; Mr. G. H. Knowlton; 

 Mr. A. C. Burrill ; and Dr. Paul Y. Babiy. 



To all of these who have assisted me I wish to express my gratitude 

 and thankful appreciation. 



Clarence E. Mickel. 



St. Paul, Minnesota, Decerriber 3, 1926. 



