A NEW GENUS AND SPECIES OF BORBORID FLIES 

 FROM SOUTH AMERICA 



By Mario Bezzi 



Of Turin, Italy 



Through the courtesy of Dr. J. M. Ahh'ich, of the United States 

 National Museum, I have received for study a most extraordinary 

 acalyptrate fly, collected in Bolivia by Dr. William M. Mann, 

 when he was a member of the Mulford Biological Exploration in 

 1921-22. 



The fly belongs to the Borboridae. Owing to the conformation 

 of the hind tarsi it is a member of the Borhoridae verae^ and on 

 account of the presence of a pair of strong ocellar bristles, it is 

 more nearly allied with the genus Bor'horus, in the broad sense, 

 than with the South American genus jUxhihorhorus Duda, 1921. 

 But it is abundantly differentiated from all the known genera by 

 the following peculiarities: Form of face, presence of a pair of 

 decussate bristles on anterior part of frons, great development of 

 the prelabrum and of the proboscis, presence of three sternopleural 

 bristles, great development of the postscutellum and of the meso- 

 phragma, form and structure of the abdomen, rounded terminal 

 bend of the fifth longitudinal vein, length of the sixth longitudinal 

 vein, etc. 



Especially the form and structure of the proboscis are very 



strange and diiferent from what is observed in the acalyptrate flies, 



recalling the condition present in some Empididae, or in the 



Bombyliid genus Empidideiciis Becker. In the Phoridae and in 



the Acalyptratae (with the exception of the Conopiclae) forms with 



elongate proboscis are indeed rather scarce and they have as a rule 



the proboscis thin and geniculate. Thus Psyllomyia Loew^, 1857, or 



Rhynchomicropteroti Annandale, 1912, among the former; and 



among the latter certain Milichiidae, like Eusiphona Coquillett, 



1897, Paramyia Williston, 1897, Aldrlchiella Hendel, 1911, and even 



Madiza {M allochiella) ; a number of Trypaneidae, like Myiopites, 



Ensina, etc. ; some Chloropidae, like Siphonella; or Ephydridae, like 



Rhynchopsilopa Hendel, 1913, etc. 



« _^_______ 



^ O. Duda, Tijdschr. v. Entom., vol. 04, 1921, p. 124, and Archiv. fur Naturgcsch., •s'ol. 

 89, Abt. A, 1923, pp. 42-52. See also A. Spuler, Troc. Acad. Nat. ScL Philadelphia, 

 vol. 75, 1923, pp. 309-378. 



No. 2621.— Proceedings U. S. National Museum, Vol. 68, Art. 20. 



79669—20 



