Synopsis. Orbit strongly differentiated; in male 
ors lacking (fig. 203), orbital setulae particu- 
larly strong and numerous in male; male without 
vibrissal fasciculus but facial keel bulbous, al- 
most spherical; proboscis elongate; 3 strong 
postsutural dc; mesonotum and abdomen shining 
black; squama gray, fringe black; wing (fig. 204) 
length 2-2.3 mm; male genitalia with aedeagus as 
in figures 205, 206. 
Host/Early Stages. Taraxacum officinale . Larva 
mining in stalks and midrib of leaves (Frost, 
1924: 46), pupating at leaf base but unknown. 
Distribution. Widespread in northern half of 
United States from California to New York (Frick, 
1959: 372); new and most southerly records: Colora- 
do, Mt. Evans area, up to 10,600 ft, 14 m. , 8 f., 
VI-VII.1961 (CNC) ; North Carolina, Highlands, 1 m. , 
13.V.57 (J. C. Vockeroth, CNC); Virginia, Pulaski 
Co., Pulaski, 4m., 1 f . , 7.V.79 (USNM); wide- 
spread in Canada, N. Europe. 
References. Melander, 1913: 260; Frick, 1959: 372; 
Spencer, 1969a: 91. 
Orbital setulae reclinate; ors present in both 
sexes 20 
20 (19). Frons strongly projecting above eye, parafacial 
prominent 0 . boulderensis Spencer, n. sp. 
Synopsis. Large species, wing length in male 2.5 
mm; gena and parafacial broad (fig. 207); strong 
vibrissa, triplicated, but not fully fused; facial 
keel raised, conspicuous; male genitalia with ae- 
deagus as in figures 208, 209. 
Host/Early Stages. Unknown. 
Distribution. Colorado. 
Reference. Part 2, p. 252. 
Frons not projecting above eye, parafacial linear — 21 
21 (20). Mesonotum and abdomen black 0. commendata Spencer 
Synopsis. Wing length in male 2.3 mm; frons broad, 
twice width of eye; gena deepest in center, 0.25 
height of eye; vibrissa slender; mesonotum and ab- 
domen shining black; squama gray, margin and 
fringe black; male genitalia with aedeagus as in 
figures 210, 211. 
Host/Early Stages. Unknown. 
Distribution. California. 
Reference. Spencer, 1981: 73. 
— Mesonotum and abdomen greenish 
0 . bernardinens is Spencer 
Synopsis. Wing length in male 2.25 mm; frons 1.5 
times width of eye; facial keel broad, gena nar- 
row, 0.20 height of eye; mesonotum and abdomen 
brilliantly shining, greenish black; male geni- 
talia with aedeagus as in figures 212, 213. 
Host/Early Stages. Unknown. 
Distribution. California. 
Reference. Spencer, 1981: 73. 
22 (13). Frons broad, twice width of eye 23 
43 
