chaixiana (Groschke) by Spencer (1969a: 
115). This misidentification resulted 
from Groschke having reared two 
separate species from the same host, 
Poa chaixii Villars, and at the same 
locality in southern Germany. The 
specimens of C . chaixiana available 
at the time in fact represented C. 
fasciata . This confusion in Groschke* s 
type series of C, chaixiana was 
discussed and clarified by Spencer 
(1978). 
A single male of (3. fasciata has now 
been seen from North Carolina, Mitchell 
County, Roan Mountain, 6,200 feet, 
13. VIII. 57 (J. G. Chillcott) , in CNC. 
The species is distinctive in having 
yellowish orbits, and the thickened 
end of the distal tubules of the 
aedeagus is also characteristic (fig. 
610). 
Nowakowski (1973: 244) considered that 
C. fasciata , C. grisea Ryddn from 
Sweden, and the nearctic species here 
treated as £. fasciata might represent 
three sibling species. However, the 
differences are so slight that we 
consider such splitting unjustified 
without more substantial biological 
evidence and therefore treat the 
populations in Canada and America as 
identical with the European C. 
fasciata . 
Cerodontha ( Dizygomyza ) latifrons 
Spencer, new species 
(Fig. 596) 
Head. Frons exceptionally broad, 3 
times width of eye, not projecting 
above eye in profile; orbit broad, 
strongly differentiated, with 2 ors 
and 3 ori, all equal, orbital setulae 
sparse, reclinate; gena extended at 
rear, 0.2 height of eye; 3d antennal 
segment greatly enlarged in male, 
slightly longer than broad, thickly 
covered with pubescence as long as 
basal width of arista, this bare, only 
slightly widening basally. 
Mesonotum. 3+1 dc, presutural strong, 
equal to 3d, acr sparse, in 6 rows in 
front, 4 behind, prsc strong, equal to 
3d dc. 
Wing. Length in male 3 mm, last 
section of M 3+4 only slightly longer 
than penultimate, inner crossvein at 
midpoint of discal cell. 
Color. Frons dark brown, orbit 
contrastingly yellow; lunule brownish, 
more silvery below; antenna black; 
mesonotum matt gray; pleura dark apart 
from narrow yellow upper margin of 
mesopleuron; legs black, knees bright 
yellow, slightly darker on p 3; abdomen 
slightly yellow laterally, all tergites 
narrowly yellow on hindmargin; squama 
and fringe, also wing base, yellow. 
Male genitalia. Aedeagus (fig. 596) 
with proximal and distal curves equal, 
distal tubules diverging at angle of 
90°, with slight gap at distal end; 
sperm pump fanlike, unusually broad. 
Host/early stages. Unknown. 
Holotype m. , North Carolina, Sevier 
Co., Clingman's Dome, Great Smoky 
Mountains National Park, 6. VIII. 57 (C. 
J. Durden), in CNC. 
Remarks. This species is immediately 
distinguishable from C . poolei , n. 
sp., from Colorado, with the frons 
even broader and by the conspicuously 
yellow knees on all legs. The male 
genitalia (figs. 596, 604) indicate 
that the two species are not closely 
related . 
Cerodontha ( Dizygomyza ) magnicornis 
(Loew) 
(Fig. 595) 
Agromyza magnicornis Loew, 1869: 46. 
Holotype male from Pennsylvania in 
MCZ . ! 
Phytobia (Dizygomyza) magnicornis, 
Frick, 1952a: 396; 1959: 384. 
Cerodontha ( Dizygomyza ) magnicornis , 
Nowakowsjki, 1973: 222. 
This species was previously synonymized 
with C . morosa Meigen (Spencer, 1969a: 
121) before the correct identity of C . 
morosa was known. Nowakowski (1973) 
pointed out that the two species are 
distinct . 
283 
