many shorter papers between 1951 and 
1958, including a valuable revision of 
the difficult genus Calycomyza (1956). 
Little further work was done on North 
American Agromyzidae until a comprehen- 
sive revision of species in Canada and 
Alaska was published by Spencer 
(1969a). Here many United States 
species were further clarified, 
particularly by the illustrations of 
the male genitalia, which had assumed 
cardinal significance for the 
identification of many species. 
The Agromyzidae of Florida were 
reviewed by Spencer and Stegmaier 
(1973) after they had collected 
throughout the State, particularly in 
the Miami area by Stegmaier. A 
detailed revision of California 
species was given by Spencer (1981) 
and 132 new species were described. 
Sehgal (1968, 1971) described several 
new species in Alberta, and Griffiths 
(1973a-80) published a series of 14 
papers on boreal Agromyzidae. Several 
species described in these papers have 
been identified in the United States. 
Steyskal (1972-81) published 
several short papers describing some 
new species, including a useful 
revision of the new genus Haplopeodes . 
DIAGNOSTIC CHARACTERS OF THE 
AGROMYZIDAE 
External Morphology 
The terms used in the descriptions and 
diagnoses have been adopted by most 
recent workers on the Agromyzidae and 
are familiar to dipterists. For the 
convenience of other entomologists, 
the terms used are indicated in 
figures 1 and 2 and are briefly 
defined here. 
Acrostichals (acr) — Minute hairs lying 
between the two lines of dorsocentral 
bristles (dc). 
Arista — Slender, bristlelike appendage 
to dorsal surface of third antennal 
segment . 
Coxa — First or basal section of leg; 
femur is third section of leg (color 
frequently is important). 
Frons — Rectangular area between rear of 
head (vertex) and lunule and 
laterally between orbits. 
Gena (jowl, cheek) — Membranous or 
lightly sclerotized area below eye 
(width and shape are frequently 
important). (See also parafacial.) 
In descriptions, entire surface from 
lower edge of eye to lower edge of 
head is termed "gena." Its height 
is given as a decimal, because the 
simplest accurate way to determine 
this is to measure the gena and the 
eye with a microscope, using a 
measuring device, and to divide the 
former measurement by the latter. 
Halter — Knoblike, modified hindwing 
functioning as a balancing organ; 
only found in Diptera (color can be 
significant) . 
Humerus — Shoulder or anterior angle 
of mesonotum anterior to notopleuron. 
Recent morphological usage terms 
this "postpronotum. " 
Lower orbital bristles (ori) — One to 
four partially incurved or reclinate 
bristles on lower half of orbits. 
Lunule — Semicircular sclerotized 
surface above antennae and adjoining 
lower margin of frons. 
Mesonotum — Dorsal area of thorax 
bearing important dorsocentral 
bristles and acrostichals (color is 
important in many species). 
Mesopleuron — Large rectangular area 
below notopleuron (color is 
important in most genera of 
Phytomyzinae. ) 
Notopleuron — Triangular area on side 
of thorax immediately below or 
lateral to transverse suture of 
mesonotum. 
Ocellar triangle — Triangular plate on 
3 
