238); puparium more rarely black, posterior 
spiracles each with some 15 bulbs on 2 arms, each 
process on a short stalk. 
Distribution. New records: Arkansas, New York, 
Pennsylvania; Canada. 
References. Frost, 1924: 42 (as 0. curvipalpis 
var. texana ) ; Spencer, 1969a: 96; part 2, p. 257. 
Vibrissal fasciculus short, broad 
0 . coniceps (Malloch) 
Synopsis. Wing length 2-2.2 mm; frons little wider 
than eye; gena extending forward, forming angle of 
approx. 45°; fasciculus in male frequently not 
fully fused (fig. 239); facial keel bulbous at 
base of antennae, furrowed above; mesonotum and 
abdomen shining black; male genitalia with ae- 
deagus as in figures 240, 241. 
Host/Early Stages. Sonchus asper (doubtless other 
related Asteraceae). Larva mining stem but un- 
known . 
Distribution. California, Indiana, Louisiana, 
Utah (Frick, 1959); widespread in Canada. 
References. Malloch, 1915a: 107; Frick, 1959: 369; 
Spencer, 1969a: 851; 1981: 75. 
33 (31). Facial keel with prominent central furrow 
0 . virginiensis Spencer, n. sp. 
Synopsis. Wing length from 2.1 mm in male to 2.5 
mm in female; short but prominent vibrissal 
fasciculus in male, vibrissal corner forming angle 
of approx. 45°; gena narrow, 0.14 height of eye; 
mesonotum and abdomen only moderately shining; 
ocellar triangle moderately shining black; male 
genitalia with aedeagus as in figures 242, 243. 
Host/Early Stages. Unknown. 
Distribution. Virginia. 
Reference. Part 2, p. 260. 
Facial keel without furrow 0 . obstipa Spencer 
Synopsis. Wing length 2 mm; vibrissal fasciculus 
in male long, slender (fig. 244); gena broad, al- 
most 0.25 height of eye; ocellar triangle bril- 
liantly shining black; mesonotum and abdomen 
strongly shining; male genitalia with aedeagus as 
in figures 245, 246. 
Host/Early Stages. Unknown. 
Distribution. Florida. 
Reference. Spencer and Stegmaier, 1973: 62. 
34 (25). Very small species, wing length less than 2 mm 35 
Slightly larger species, wing length at least 2 mm- 41 
35 (34). Veins conspicuously pale O. debilis Spencer 
Synopsis. Wing length 1.4-1. 5 mm, last section of 
M 3+4 normally slightly longer than penultimate; 
ocellar triangle large, broad, apex extending to 
level of lower ors; gena narrow, at most 0.20 
height of eye; vibrissal fasciculus in male 
short, tapering (fig. 247); ocellar triangle, 
mesonotum, and abdomen shining black; wing and 
veins pale; male genitalia with aedeagus as in 
figures 248, 249. 
46 
