area in Sri Lanka (Spencer, 1975). 
Species are certainly present in all 
States in America, but, as might be 
expected, the genus is better 
represented in the north than in the 
south. Of 99 described species 
recorded here (2 unnamed), only 7 were 
discovered in a detailed survey of 
Florida (Spencer and Stegmaier, 
1973). However, 17 species are now 
known in Colorado, several from 
elevations up to 14,000 ft on Mt. 
Evans . 
Sixteen new species are described here 
and in addition 11 species are 
recorded as new to the United States, 
all previously known in Canada (part 
2, p. 309); 1 species, P. wahlgreni , 
is new to North America. One new 
synonym is established (part 2, p. 321). 
Of 78 other species in Canada and 
Alaska (Spencer, 1969a; Sehgal, 1971; 
Griffiths, 1972a et seq.), many will 
be found in the Northern States or at 
high elevations farther south. 
Three species must be deleted from the 
United States list, as records given 
by Frick (1959) are based on misidenti- 
fications. P. albiceps is now known 
as an exclusively palaearctic species, 
and the record given by Frick (1959: 
424) refers to ]?. alaskana ; ruf ipes 
recorded from Oregon by Frick (1959: 
435) has been found to represent P. 
f lavicornis ; and P. nigripennis , 
recorded by Frick (1959: 433) from 
Wisconsin, represents £. saskatoo- 
nensis . 
There is great diversity in color, 
head shape, size, and male genitalia 
in Phytomyza . The color and shape of 
the puparium and also the arrangement 
of the larval spiracles vary consider- 
ably. Nevertheless, a number of 
species groups cannot be satisfactorily 
identified on external characters 
alone, and for positive identification, 
examination of the male genitalia is 
necessary. Examples are the _P. 
albiceps group (comprising species 
with the frons black or yellow, with 
the hosts in the Apiaceae and 
Asteraceae) , all of which have conspic- 
uous bristles adjoining the basal 
sclerites of the aedeagus (see figs. 
1196, 1247); the P. robustella group, 
represented in America by ]?. 
alamedensis , J?. crepidis , flavens , 
P. integerrimi , and P. wahlgreni , in 
which the larva feeds predominantly on 
the midrib of the leaf, frequently 
forming a gall-like swelling and 
pupating at the leaf base; and the J?. 
ilicicola group of holly leaf miners, 
with six species discussed here, in 
which identification of adults is 
difficult even from the male genitalia 
but which are largely host specific 
and with characteristic leaf mines 
(see figs. 1305, 1316). 
The host is known of 63 species in the 
United States, although in many 
instances in which relationships are 
apparent from the male genitalia, the 
host can be assumed with some 
confidence (at least the plant 
family). Examples are Y_. nigrinervis 
and P^. saskatoonensis , which are 
certainly feeders on Ranunculaceae. 
The larvae of most Phytomyza species 
are leaf miners, but some feed 
internally in seeds or stems. Usually 
pupation takes place externally, the 
larva transforming as it leaves the 
mine, and the puparium either falls to 
the ground immediately or may for a 
time be loosely attached to the leaf 
until dislodged by wind or rain. In 
the P. ilicicola and robustella 
groups the anterior spiracles slightly 
project through the leaf epidermis. 
Genus Chromatomyia Hardy 
Chroma tomyi a Hardy, 1849: 385. Type 
of genus: Phytomyza periclymeni 
Meijere, 1924 (as ]?. obscurella 
Fallen, 1823b) (Europe). 
This genus was erected for seven 
species in Europe having "slipper- 
shaped pupae," which remain in the 
leaf at the end of the mine, as 
opposed to the barrel-shaped pupae of 
Phytomyza , which transform "on the 
ground." 
173 
