turn matt gray, almost silvery, 3+1 strong dc, acr 
in 2 rows; scutellum grayish yellow, paler cen- 
trally; pleura largely yellow, apart from black 
band on lower margin of mesopleuron and sterno- 
pleuron; legs with femora yellow, tibiae and tarsi 
slightly darker, brownish yellow; knob of halter 
yellow below, black above; wing length from 2 mm 
in male to 2.25 mm in female; male genitalia with 
aedeagus (figs. 1013, 1014) curving dorsally at 
end; epandrium with line of short bristles along 
inner margin, surstylus with comb of 8 strong 
bristles (fig. 1015). 
Host/Early Stages. Unknown. 
Distribution. Northern California. 
Reference. Spencer, 1981: 328. 
— Palpus black 21 
21 (20). Femora yellow F. varia (Melander) 
Synopsis. Frons brownish behind, more yellow be- 
low; face and gena yellow; 2 ors, 1 ori, orbital 
setulae sparse, upright; 3d antennal segment 
black, 2d yellow; mesonotum matt, brownish gray, 
3+1 strong dc , acr sparse, in 2 rows in front; 
scutellum predominantly dark but faintly yellow 
centrally, particularly when viewed from rear; 
legs yellowish brown (holotype) ; knob of halter 
black above; wing length 2.5 mm in female; male 
genitalia with sperm pump as in figure 1022, with 
blade broad. 
Host/Early Stages. Unknown. 
Distribution. Idaho. 
References. Melander, 1913: 264; part 2, p. 305. 
— Femora black _P. volatilis Spencer 
Synopsis. Frons yellowish, 3d antennal segment 
black, 2d at most faintly paler, grayish; orbital 
setulae upright, a few in front more proclinate; 
mesonotum matt brownish black; notopleural tri- 
angle yellowish, mesopleuron largely black, nar- 
rowly yellow along upper margin; legs black; knob 
of halter black; male genitalia with aedeagus 
(figs. 1016, 1017) bending dorsally at end; epan- 
drium with comb of 5 or 6 bristles at midpoint, 
lined with slender hairs, surstylus long, slender, 
not greatly widening at end (fig. 1018); sperm 
pump small, with narrow blade (figs. 1019-1021). 
Host/Early Stages. Unknown. 
Distribution. Colorado (new record); Canada, 
northern Sweden. 
References. Spencer, 1969a: 202; part 2, p. 305. 
160 
