time permits, remove the individual 
puparia from the flower heads to 
prevent their destruction by any 
developing mold or desiccation if kept 
dry. Also this procedure insures 
correct association of adults with 
their puparia, as two species may often 
be present in a single flower head. 
PRESERVING ADULTS 
Emerging flies should not be killed 
too soon. They should be allowed to 
live for at least 24 hours to insure 
complete hardening and full color 
development. Ideally they should be 
mounted using minuten pins, although 
gluing either to a stronger pin or to 
a card point can be satisfactory. If 
time or facilities do not permit, the 
specimens should be kept dry in layers 
of cellulose acetate, in either vials 
or small boxes containing all relevant 
data, including locality, collection 
date, host plant, and emergence date. 
Handle dry specimens with greatest 
care to prevent damage to such parts 
as antennae, bristles, and legs, which 
may be vital for accurate identifica- 
tion. 
Preserving specimens in alcohol is not 
recommended. Although satisfactory 
techniques exist for drying such 
specimens, they are time consuming and 
can be avoided if necessary attention 
is given to preserving them dry. 
SYSTEMATICS 
The division of the Agromyzidae into 
the two subfamilies Agromyzinae and 
Phytomyzinae, originally proposed by 
Fallen (1823a, b), has been accepted 
in all subsequent revisionary studies 
of the family. The two subfamilies 
are characterized by the termination 
of the subcosta in vein R 1 in the 
Agromyzidae (figs. 4, 204) and by the 
subcosta running parallel to R 1 and 
reaching the costa independently in 
the Phytomyzinae (figs. 5, 957). In 
the larvae, the cephalopharyngeal 
skeleton has two upper arms in the 
Agromyzinae (figs. 6, 435) but only 
one in the Phytomyzinae (figs. 7, 
667). These differences are not 
entirely clear cut, particularly in 
the genus Phytobia , but they are of 
considerable practical value as a 
first step in identification. 
Since 1930, workers on the Agromyzidae 
have based their systematics on the 
generic framework established by 
Hendel (1931-36) for palaearctic 
species. This was partially modified 
by Frick (1952a) to include nearctic 
and neotropical species. In Frick's 
concept, Hendel' s genus Dizygomyza was 
treated as Phytobia with 10 subgenera. 
Phytobia is now restricted to tree- 
feeding species. Of the other 
subgenera, Amauromyza , Nemorimyza , and 
Calycomyza are accepted as full 
genera, whereas Ic teromyza , Poemyza , 
and Dizygomyza are treated as subgenera 
of the genus Cerodontha , as proposed 
by Nowakowski (1962). Phytagromyza is 
also now included in Cerodontha , and 
for its well-understood original con- 
cept, the available name Paraphytomyza 
is adopted. 
Other generic changes that should be 
noted are the erection of Galiomyza 
Spencer (1981) for a small segregate 
of Liriomyza , the new name Haplopeodes 
Steyskal (1980) for Haplomyza Hendel, 
and the acceptance of Chroma tomyia 
Hardy, proposed by Griffiths (1974a) 
as a segregate of Phytomyza , based 
essentially on characters of the male 
genitalia and in part on the method of 
pupation. 
During our research, generic limits 
have been slightly modified in three 
genera following the study of fresh 
material. The essential character of 
the small genus Hexomyza was 
previously considered to be the 
production of twig galls by the 
larvae. The male genitalia of the 
species forming conspicuous galls on 
Tilia americana (fig. 192), "Agromyza " 
tiliae , associate it with species 
accepted in Ophiomyia , and Hexomyza is 
now restricted to gall causers on 
Salicaceae. " Agromyza " rutiliceps is 
13 
