Host/Early Stages. Ilex aquifolium . Larva 
forming upper surface linear blotch, oviposi- 
tion takes place at base of midrib on lower 
surface and larva feeds slowly during summer, 
by autumn forming small greenish mine, over- 
wintering in leaf and completing feeding and 
transformation following spring, pupation in 
mine; puparium yellowish brown. 
Distribution. Oregon, Washington; Canada 
(introduced), Europe. 
References. Frick, 1959: 429; Kulp, 1968: 19; 
Spencer, 1969a: 246. 
Acr in 4 rows Chroma tomyi a montana Spencer 
(Frons predominantly dark, see couplet 92.) 
52 (50). Acr present, in 2-6 rows 53 
— Acr lacking (at most 1 or 2 isolated hairs pres- 
ent) Chroma tomyi a syngenesiae Hardy 
Synopsis. Frons orange yellow, orbit with 2 
short, equal ors and 1 ori; 3d antennal segment 
small, round, black, 1st and 2d yellowish; 
mesonotum conspicuously ash gray; legs black 
but femora with all knees bright yellow; squama 
yellow, margin and fringe black; wing length 
2. 2-2.6 mm, 2d costal section short, 1.33-2 
times length of 4th; male genitalia with aedea- 
gus (figs. 1186, 1187) having supporting scle- 
rites slender, diverging apically. 
Host/Early Stages. Primarily Asteraceae (appar- 
ently exclusively so in California), rarely 
recorded on other hosts but such records fre- 
quently referring erroneously to related 
species, common on Sonchus . Larva forming 
conspicuous white linear mine, pupating in 
leaf . 
Distribution. California, Massachusetts, 
Oregon, Washington; Australia, Canada, Europe, 
Japan, New Zealand (introduced and widespread 
in temperate areas). 
References. Griffiths, 1967: 7; Spencer, 1969a: 
278; 1981: 453; Frick, 1972: 1310. 
Note. This is 1 of 2 species referred to in 
earlier literature as Phytomyza atricornis Mg.; 
2d species, Chromatomyia horticola Goureau, 
does not occur in North America. 
53 (52). Acr numerous, in 5-6 rows IP. aquilegiana Frost 
Synopsis. Frons and orbit yellow, 2 equal ors, 
1 or 2 ori; mesonotum and scutellum blackish; 
side of thorax dark, mesopleuron only narrowly 
yellow along upper margin; legs black, only 
foreknee distinctly yellow; squama pale, margin 
dark brown, fringe at least partially dark; 
wing length 2. 4-2. 7 mm, 2d costal section long, 
4 times length of 4th; male genitalia with ae- 
deagus as in figures 1188, 1189. 
Host/Early Stages. Aquilegia spp. Larva 
forming large greenish blotch mine, with frass 
192 
