Host/Early Stages. Festuca , Lolium (U.S.A.), 49 
other genera of Poaceae, mainly in Europe, re- 
corded by Griffiths (1980). Larva forming nar- 
row linear mine, with long anterior spiracles 
of puparium (fig. 1266) projecting through 
epidermis . 
Distribution. California, Oregon; Canada, 
Europe . 
References. Spencer, 1969a: 259 (as Phytomyza ) ; 
1981: 447; Griffiths, 1980: 49 (here C. nigra 
is treated as superspecies with 6 forms, 1 of 
which is North American (Pacific coast) form. 
Differences between these forms are slight, but 
Griffiths considers that they may in due course 
be upgraded to distinct species). 
Eye bare or at most with few scattered hairs 97 
97 (96). Frons conspicuously projecting above eye; 3d an- 
tennal segment slightly elongate; proboscis 
elongate Napomyza evanescens (Hendel) 
Frons not significantly projecting above eye 98 
98 (97). Legs entirely black 99 
At least foreknee distinctly yellowish 100 
99 (98). 2 d costal section more than 2 times length of 
4th; frons paler, brownish, above 
Chroma tomyi a griffithsi Spencer, n. sp. 
Synopsis. Frons blackish below, 2 ors, 2 ori, 
3d antennal segment small, round; mesonotum 
matt grayish black, acr in 4 rows; wing length 
2.5-3 mm, 2 d costal section normally 2.3 times 
length of 4th; male genitalia with aedeagus as 
in figure 1267, supporting sclerites as in 
figure 1268. 
Host /Early Stages. Unknown. 
Distribution. Colorado. 
Reference. Part 2, p. 326. 
2 d costal section less than 2 times length of 
4th; frons deep black P. nigrinervis Frost 
Synopsis. Frons broad, twice width of eye, deep 
black, orbit pronounced, generally paler, 
slightly gray; 2 equal ors, normally 1 ori, 
sometimes additional one in front; all anten- 
nal segments black, 3d slightly enlarged; meso- 
notum matt blackish but with faint brownish 
tinge, acr sparse, in 2 rows; legs entirely 
black; squama gray, margin and fringe deep 
black; wing with veins R 2 and R 3 conspicuous- 
ly black, length 2 . 5-2 . 6 mm, 2 d costal section 
normally 1.7, at most 2 times length of 4th; 
male genitalia with aedeagus as in figures 
1269, 1270. 
Host/Early Stages. Unconfirmed but almost 
certainly Ranunculaceae (deduced from male 
genitalia) . 
Distribution. Colorado (type series of 10 
specimens); new records: Colorado: Clear Creek 
Co., Mt. Evans, Summit Lake Flats, 12,800 ft, 
208 
