2 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 123 



We wish to thank the following persons for assistance with this 

 study and for the loan of specimens (abbreviations in parentheses 

 are used in distribution records, which are quoted directly from 

 museum labels under "Specimens Examined") : Dr. George W. 

 Byers, Snow Entomological Museum, University of Kansas, Lawrence, 

 Kansas (UK) ; Jose Carillo, Instituto Nacional Investigaciones 

 Agricolas, Chapingo, Mexico (INIA) ; Dr. I. J. Cantrall, University 

 of Michigan, Museum of Zoology, Ann Arbor, Michigan (UMMZ) ; 

 Dr. P. J. Darlington, Museum of Comparative Zoology, Harvard 

 University, Cambridge, Massachusetts (MCZ) ; Dr. Henry F. Howden, 

 Canadian National Collection, Ottawa, Canada (CNC) ; J. N. Knull, 

 Ohio State University, Columbus, Ohio (OSU) ; Hugh B. Leech, 

 California Academy of Science, San Francisco, California (CAS) ; 

 Dr. Milton W. Sanderson, Illinois Natural History Survey, Urbana, 

 Illinois (INHS) ; Dr. Richard B. Selander, University of Illinois, 

 Urbana, Illinois (UI) ; Dr. A. M. Villiers, Museum National d'Histoire 

 Naturelle, Paris, France (MNHP); Dr. F. G. Werner, University 

 of Arizona, Tucson, Arizona (UA) ; and Ing. Fernando de Zayas, 

 Havana, Cuba (Z). We would especially like to thank Dr. John C. 

 Moser, Southeastern Forest Experiment Station, Alexandria, La., 

 for specimens and information on the new species. 



Biology and ecology. — It is not surprising that very little infor- 

 mation is available on the biology of insects such as Euparixia, which 

 have restricted and secretive habits. Fewer than 50 specimens are 

 known for all five species of Euparixia and the immature forms are 

 completely unknown. Most of the specimens represent E. duncani 

 and were collected at electric lights. Three of the species (E. formica 

 Hinton, E. bruneri Chapin, and E. moseri, new species) have been 

 collected in the nests of leaf-cutting ants of the genus Atta. The 

 genera Euparia, Euparixia, Euparixoides, and Cartwrightia seem to 

 form a natural group in the Eupariini, all of which are apparently 

 myrmecophilous. 



Even though Euparixia duncani is represented by the greatest 

 number of specimens, its host relationships have not been established; 

 however, because of its similarity to the other species in the genus, 

 we would also expect it to occur in the nests of leaf-cutting ants. 

 Most specimens have been collected at Tucson and Globe, Ariz., 

 where no species of Atta have been found. Another leaf-cutting ant, 

 Acromyrmex versicolor (Pergande),does occur in this area and is the 

 suspected host ant. Creighton (1950, p. 325) stated: "In both 

 structure and habits the ants of the genus Acromyrmex show a close 

 relationship to the genus Atta." 



Presumably the beetles are scavengers and live in close harmony 

 with the ants. Their occurrence at great depths (to 12 feet) would 



