Agromyza hockingi Spencer (new to 
U.S.A.) 
(Figs. 411-413) 
Agromyza hockingi Spencer, 1969a: 44. 
Holotype male from Alberta in CNC. 
Specimens have now been identified 
from three States and are recorded 
here . 
In the type series the squamal fringe 
was somewhat variable, ochreous to 
brownish. In the specimens now seen 
it would be considered as pale, but 
the male genitalia (figs. 411-413) and 
in particular the distinctive arrange- 
ment of bristles within the epandrium 
(fig. 413) are diagnostic and in the 
specimen from Colorado exactly as in 
the type series. 
New records. 
Colorado, Clear Creek Co., Mt. Evans, 
Doolittle Ranch, 9,800 ft, 3. VIII. 61 
(C. H. Mann), in CNC. 
Texas, Kerr Co., Kerrville, 1 m. , 
31. III. 59 (J. F. McAlpine), in CNC. 
Utah, Cache Co., Green Canyon, 1 m. , 
25-31. VII. 68 (J. Hanson, Malaise 
trap), in USU. 
Agromyza isolata Malloch 
(Figs. 437, 438) 
Agromyza isolata Malloch, 1913a: 306. 
Holotype female from California in 
USNM. 
Agromyza populoides Spencer, 1969a: 
52. Holotype male from Saskatchewan 
in CNC. NEW SYNONYM. 
With only a female known, the identity 
of A* isolata has long been in doubt. 
It was considered to be a member of 
the A. potentillae (= spiraeae ) group, 
but identification in the absence of 
males was problematic. The one 
distinctive character was the 
yellowish tibiae and tarsi. 
A female recorded from Populus 
deltoides at Hoquiam, Grays Harbor 
County, Wash. (Greene, Lot 44-22553), 
identified by Greene as A. isolata , 
presumably after comparison with the 
holotype, has now been examined and 
this identification is accepted. This 
species, occurring as a leaf miner on 
both Populus and Salix , is common and 
widespread in Canada and also in 
California and Washington. In Canada 
it was described as A. populoides , and 
west coast specimens in the United 
States were misidentif ied by Frick 
(1959: 353) as the European species A. 
albitarsis Meigen. The new synonymy 
°f A. populoides with A. isolata can 
thus now be formally established. 
Agromyza kincaidi Malloch 
(Figs. 376, 377) 
Agromyza kincaidi Malloch, 1913a: 
285. Holotype female from Alaska in 
USNM. 
Frick (1959: 353) treated A. kincaidi 
as a synonym of A. ambigua Fallen (in 
the sense of earlier authors, i.e., A. 
nigrella Rondani), but this synonymy 
is not accepted. A. nigrella is 
indeed very close to A. kincaidi but 
is substantially smaller. 
From the male genitalia it is clear 
that A. kincaidi is a grass feeder. 
No specimens have been reared, but two 
exceptionally large puparia 3.2 mm in 
length were obtained from larvae 
feeding on Bromus purgans at Ouachita 
State Park, near Hot Springs, Ark., 
15.V.79 (KAS), and it is believed that 
these can only represent A. kincaidi . 
New records. 
Colorado, Clear Creek Co., Mt. Evans, 
Doolittle Ranch, 9,800 ft, 1 f., 
22. VII. 61 (J. G. Chillcott ) , in CNC; 
1 m. , 1 f., 3 and 8. VIII. 61 (W. R. 
M. Mason and B. H. Poole), in CNC; 
Echo Lake, 10,600 ft, 1 f . , 
25. VII. 61 (C. H. Mann), in CNC. 
Tennessee, Sevier Co., Indian Gap to 
Clingman's Dome, 5,200-6,600 ft, 1 
m. , 6. VIII. 57 (J. G. Chillcott), in 
CNC. 
Utah, Weber Co., North of Huntington, 
1 f., 16. VI. 66 (G. F. Knowlton), in 
USU. 
264 
