Proceedings of 
the United States 
National Museum 
SMITHSONIAN INSTITUTION + WASHINGTON, D.C. 
Volume 113 1962 Number 3465 
THE HELEOMYZID FLIES OF AMERICA NORTH OF MEXICO 
(DIPTERA: HELEOMYZIDAE) 
iBy Gorpon D. Git! 
Introduction 
Adults of the North American Heleomyzidae may be distinguished 
from all other acalyptrate Diptera by the following combination of 
characters: postocellar bristles convergent, one or two fronto-orbital 
bristles, frontal plates present, oral vibrissae present, tibiae with 
dorsal preapical bristles, costal break near union of subcosta (auxiliary 
vein) with costa, subcosta entirely separate, costal spines present. 
In Borboropsis Czerny and Oldenbergiella Czerny, the dorsal preapical 
bristles of the tibiae are absent or inconspicuous, as are the costal 
spines; however, the specimens assigned to these genera appear to be 
typical heleomyzids in all other respects. 
The frontal plates are strips, usually pollinose, which extend forward 
from the vertex on either side of the front and are differentiated from 
the surrounding area of the front. Their exact position varies in the 
subfamilies of Heleomyzidae. 
Although the male terminalia have been used to some extent in the 
taxonomy of the Heleomyzidae and are sometimes mentioned briefly 
in species descriptions, illustrations or detailed accounts of their 
structure have for the most part been inadequate. However, Collart 
(1933, 1940) published some excellent illustrations of certain species 
1Department of Biology, Northern Michigan College. This study was conducted in partial fulfillment 
of the requirements for the degree of Doctor of Philosophy from The State College of Washington, 
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