yellowish centrally; legs typically yellowish; 
wing length about 1.9 mm, discal cell relatively 
large, last section of M 3+4 rarely more than 1.5 
times length of penultimate (fig. 976); male geni- 
talia with aedeagus (fig. 977, A) ending in pair 
of long, coiled membranous tubules; hypandrium 
characteristically narrowing distally (fig. 977, 
®.) J sperm pump minute (fig. 978); surstylus with 
only few weak hairs on inner corner. 
Host/Early Stages. Asteraceae, once reared from 
Sonchus in Europe, definitely associated with 
Solidago in Canada. Larva stem miner, probably 
feeding on other genera, early stages unknown. 
Distribution. Widespread from New Mexico to 
Michigan and California to Maryland (Frick, 1959, 
as jP. immaculata ) , probably present in most 
States; new records: Colorado (incl. Mt. Evans, 
14,000 ft). North Carolina, Tennessee; Brazil, 
Canada, Chile, Europe, Greenland, Sri Lanka, 
Taiwan. 
References. Spencer, 1969a: 202; 1981: 315. 
Scutellum always yellow centrally; larger species, 
wing length 2-2.5 mm P. imperfecta (Malloch) 
Synopsis. Frons yellowish or somewhat darker; 2 
ors, 1 ori, orbital setulae distinctly proclinate; 
mesonotum largely matt gray, sometimes with faint- 
ly paler central band; scutellum yellow centrally; 
acr sparse, in 2 rows; pleura yellowish; legs yel- 
low with variable darker striations; halter pre- 
dominantly yellow but knob darkened, at least 
faintly brown; wing length from 2 mm in male to 
2.5 mm in female, last section of M 3+4 less than 
twice penultimate; male genitalia with aedeagus 
(figs. 979, 980) ending in long, paired black tu- 
bules; sperm pump (fig. 981) with blade large, 
fanlike; surstylus (fig. 982, A) with comb of nor- 
mally 6 black bristles, inner margin of epandrium 
(fig. 982, B) with numerous irregular bristles. 
Host/Early Stages. Unknown. 
Distribution. California, Florida, Idaho, Texas 
(new record), Washington; Chile. 
Reference. Spencer, 1981: 324. 
10 (7). Relatively large species, wing length up to 2.3 mm- 
beckerella Spencer 
Synopsis. Frons, gena, face, palpus, and hind- 
margin of eye yellow; frons broad, twice width of 
eye; 2 ors, 1 ori, orbital setulae proclinate; 3d 
antennal segment predominantly pale but variably 
brownish on outside, slightly longer than broad; 
eye slanting; mesonotum (fig. 983) with rectangu- 
lar yellow patch centrally adjoining scutellum, 
narrow yellow bands extending forward along line 
of dc; scutellum dull yellowish centrally; humerus 
and notopleural area yellow, mesopleuron largely 
yellow, variably darkened along lower margin; legs 
with femora basically yellow, with variable brown- 
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