NEW MUSCOID FLIES HALL 



207 



absent ; posterior dorsocentrals four ; prescutellar bristles one ; sterno- 

 pleurals three, in a triangle, the middle one but slightly posterior to 

 foremost; prosternum bare; postalar declivity bare; intrasquamal 

 setulae absent; propleura with several long bristlelike hairs at its 

 middle ; scutellum with numerous hairlike setae, with three marginal 

 bristles, apical bristles about as long as lateral and subapical bristles 

 small. 



Abdomen black, thinly grayish pollinose, tessellated; dorsally 

 without defined marginal bristles but with numerous hairlike setae; 

 fourth segment mostly red, basally the dorsum a little darkened; 

 ventrally all sternites overlapped by tergites ; hypopygium red, mor- 

 phological features (fig. 21) as illustrated. 



Wing normal, hya- 

 line ; a few basal set- 

 ulae on third vein; 

 bend of fourth vein 

 with a rounded an- 

 gle ; apical cell plain- 

 ly open near apex of 

 wing ; third costal 

 section about as long 

 as fifth and sixth 

 together. 



Legs black ; fore 

 tibia with two pos- 

 terior bristles at mid- 

 dle and with a row 

 of anterior dorsal 

 bristles; middle tibia at middle with two anterior dorsal and two 

 posterior bristles, hind tibia not ciliated, with two anterior ventral, 

 three or four anterior dorsal, and three posterior dorsal bristles. 



Type locality. — Ramsey County, Minn. 



ry/?e.— U.S.N.M. no. 51694. 



Host. — Tabanid larva. 



Remarks. — Described from the single holotype male specimen 

 reared on May 3, 1926, by Dr. C. B. Philip. 



Dipterous parasitism of tabanid larvae seems to be of rare occur- 

 rence. The records of the United States National Museum show that 

 there are but two such reported instances. An adult of the common 

 widespread bombyliid Anthrax lateralis Say was reared from the 

 larva of Tahanus annulatus Say, a horsefly that ranges over much of 

 the South Central States, and an adult of Phaslops fava Coquillett, 

 a tachinid about which little is known, w^as reared from the larva of 

 Tahanus trimaculatus Beauvais, which has a range similar to that of 

 the horsefly mentioned above. These two records are by Jones and 



Figure 21. — Myocera tabanivora, new species : a. Left 

 lateral view of male terminalia ; 6, rear view of male 

 terminalia. 



