12 PROCEEDINGS OF THE NATIONAL MUSEUM vol.78 



N. A. Dipt., 1908, p, 262, fig.— Banks, Ent. News, vol. 23, 1912, p. 109 ; 

 Annals Ent. Soc. Amer., vol. 9, 1916, p. 200. — Daecke, Ent. News, vol. 

 24, 1913, p. 45.— Krobee, Eutom. Mitteilungen, vol. 3, 1914, p. 349.— 

 Bkitton, Clieck-list Ins. Conn., 1920, p. 189. — Johannsen, List Ins. 

 New York, 1928, p. 803. 



Male. — Easily recognized by the large, opaque, pale yellow frontal 

 triangle, the elongate slender tip of which just reaches the lunule. 

 The front outside the triangle is brown in color, becoming somewhat 

 darker at vertex; the orbits are shining light yellow below, grad- 

 ually changing into brown above. The antennae are also quite strik- 

 ing, the first antennal joint is longer than usual, second very short 

 and the third fully four times the second and of orange color except 

 a dark stripe along the upper edge. Mesonotum mostly black, which 

 extends to the mesopleura behind the suture. Humeri white with 

 a yellowish area behind to the suture and mesially halfway to the 

 middle. Before the scutellum a yellowish area extends from one 

 wing to the other. Humeral 1 ; notopleural 2 ; supraalar 2. Scutel- 

 lum brown in middle. Metanotum with distinct black spot not 

 reaching sides nor upper edge. Halteres with yellow knob. 



Abdomen yellow, somewhat more brownish toward the apex. 

 First segment brown above, its sides pale yellow, all the lateral 

 bristles of the first and second segments yellow; the third, fourth, 

 and fifth segments have a pale pollinose band at base; genital seg- 

 ment yellow, bearing a pair of backwardly directed black bristles 

 standing far apart. 



Front and middle legs pale yellow, tarsi gradually darker; hind 

 femora j^ellow with two narrow dark rings; hind tibia yellow on 

 basal two-thirds, then more whitish, the apical sixth or eighth 

 quite black, as are also the tarsi. Hind trochanters and femora 

 without villous hairs; front and middle coxae with only small pale 

 hairs at tip. 



Wing subhyaline, first posterior cell hardly wider than the sub- 

 marginal cell immediately in front of it; tip of second vein much 

 farther from base than anterior end of hind crossvein. 



Female. Front and antennae as in male. Ovipositor slightly 

 longer than the remainder of the insect, the principal joint very 

 long and only slightly tapering, the terminal joint about three- 

 fifths as long, black on basal half, snow white on apical half, 

 the minute appendages at the tip darker; the hair on the last seg- 

 ment corresponds with the ground color. It is almost impossible 

 to distinguish the very small basal joint. 



Length, male 5.5 mm., female the same to the ovipositor, which 

 measures 7 mm. 



Redescribed from 27 specimens: 1 Wilmerding, Pa., no collector; 

 2 from Connecticut (Williston) ; 1 Riverton, N. J. (no collector, re- 



