and L. septentrional is — feed exclusive- 
ly on Monocotyledones . The first is 
host specific on Tr iglochin , the 
second on Commelina and Tradescant ia , 
whereas L. marginalis and L. 
septentrional is have been found on 
several genera of grasses. 
Within the United States the majority 
of species are known in the north or 
at high elevations. Ten species are 
known in Florida, but 48 were recorded 
in California (Spencer, 1981), of 
which 31 were described as new. The 
true distribution of most species 
remains to be established with further 
collecting, and it seems clear that 
the distribution of many species will 
prove to be more widespread than is 
apparent from present records, both 
from north to south and from east to 
west. For example, L. assimilis , 
previously known from Illinois and 
Pennsylvania, is now recorded from 
Texas; L. lathyri , known only from 
Alberta, was discovered in Arkansas; 
and two species, L. ptarmicae and L. 
septentrional is , known from California 
and Canada, have now been recorded 
from Colorado. 
Key to Liriomyza 1. Scutellum blackJL/ 2 
Species — Scutellum at least partially yellow 3 
2 (1). Frons yellow L. nigriscutellata Spencer 
Synopsis. Frons twice width of eye, conspicuous- 
ly projecting above eye toward base of antennae; 
1 ors, 3 ori, orbital setulae sparse or lacking; 
gena extended at rear, 0.33 height of eye, pale 
yellow, similar to face and palpus; 3d antennal 
segment yellowish brown, small, quadrate, arista 
fine, conspicuously swollen at base; mesonotum 
matt black but with weak subshine, acr in 2-3 
rows; side of thorax black, apart from narrow yel- 
low upper margin of mesopleuron; legs with femora 
black and all knees yellow, tibiae and tarsi 
largely black, slightly paler on p 1; squama 
yellowish gray, margin and fringe dark; wing 
length 1.5 mm; male genitalia with aedeagus as in 
figures 623, 624. 
Host/Early Stages. Unknown. 
Distribution. California. 
Reference. Spencer, 1981: 253. 
— Frons dark brown \L. nigrissi™a Spencer 
Synopsis. Frons twice width of eye, narrowly 
paler along inner margin of black orbit; 4 or- 
bital bristles (either 1 ors, 3 ori or 2 ors, 2 
ori); all antennal segments black; mesonotum 
deep black, moderately shining, acr in 4 rows; 
humerus and pleura black; scutellum essentially 
black but with faint brownish undertone; legs and 
abdomen black; squama dark gray, margin and 
fringe black; wing length in male 1.8 mm; male 
genitalia with aedeagus as in figures 625, 626; 
surstylus (fig. 627) elongate, with 2 short hairs 
at end; sperm pump with strongly developed base 
(fig. 628). 
.1/see also L. robiniae Valley (1982). 
108 
