LARVAL TAXONOMY OF THE TROGINAE IN NORTH AMERICA 3 



in this investigation along with those of 18 other species. Certain species 

 are distinguished in the adult stage only by characters of the male 

 aedeagus. This, plus the fact that as many as six species may occur 

 together under a single carcass (Spector, 1943), necessitated laboratoiy 

 rearings to associate the adults and larvae accurately. 



Acknowledgments 



The writer is especially grateful to Dr. Paul O, Ritcher who suggested 

 the topic, provided the assistantship, and gave most liberally of his 

 time and energies in the capacity of major professor. 



The v/riter also wishes to express his gratitude to the following in- 

 dividuals and institutions for their assistance during the course of this 

 study: O. L. Cartwright and D. M. Anderson, U.S. National Museum, 

 for the exchange of adult specimens and the loan of adults and im- 

 matures; Mrs. P. Vaurie, American Museum of Natural History, 

 for the loan and exchange of adult specimens; L. J. Bottimer, Kerr- 

 ville, Tex., Dr. M. A. Cazier and M. A. Mortenson, Portal, Ariz., 

 Dr. G. Cottam, Rob and Bessie Welder Wildlife Foundation, Sinton, 

 Tex., Dr. R. O. Drummond and Dr. O. H. Graham, Entomology 

 Research Division, U.S. Department of Agriculture, Kerrville, Tex., 

 Dr. R. I. Gara, Boyce Thompson Institute Forest Research Laboratory, 

 Beaumont, Tex., E. L. Pond, San Pedro Ranch, Carrizo Springs, Tex., 

 and V. D. Roth, Southwest Research Station, American Museum of 

 Natural History, Portal, Ariz., for the hospitality and assistance that 

 they rendered during the collecting trip through Arizona, New Mexico, 

 and Texas in the summer of 1964; J. F. Cornell, R. K. Eppley, K. 

 Goeden, D. L. Mays, G. E. Osgood, Dr. R. L. Rabb, Dr. S. Radinov- 

 sky. Dr. W. P. Stephen, and J. R. A. Willard for assistance in the 

 collection of adults and larvae; L. J, Bottimer, Dr. R. I. Gara, N. 

 McFarland, Dr. F. D. Parker, and Dr. L. A. Stange for their assistance 

 in the collection and shipment of numerous live adults to the wTiter; 

 Dr. N. Virkki, University of Puerto Rico, Agricultural Experiment 

 Station, for his studies of the spermatogenesis and chromosomes of 

 Trox and Omorgus; Dr. O. Zethner-Moller and W. H. G. Schallig for 

 their kind assistance in the translation of foreign papers; P. Schilling 

 and the Genetics Department for their help in attaining insecticide- 

 free foodstuffs for the beetles; David R. Smith for his assistance on the 

 collecting trip during the summer of 1964; Dr. J. D. Lattin, Dr. C. H. 

 Martin, Dr. F. H. Butt, and other members of the Department of 

 Entomology, Oregon State University for their advice and encourage- 

 ment. 



