Cerodontha , Subgenus Cerodontha Rondani 
Cerodontha Rondani, 1861: 10. Type of 
subgenus : Chlorops denticornis Panzer 
(Europe) . 
Distinctive characters of this subgenus 
are the spine on the third antennal 
segment (fig. 549) and the presence of 
only one pair of scutellar bristles. 
There is considerable color variation, 
from largely black through gray to 
yellow. 
Cerodontha is virtually cosmopolitan, 
with species known from Australia, 
southern Chile, and New Zealand and is 
widespread across the northern 
hemisphere. In Africa, species have 
been described from several high 
mountains and two undescribed species 
have recently been seen from Kenya 
(Tschirnhaus collection). 
Only the single species, C. dorsalis 
(Loew), is present in the United 
States. The species is remarkable in 
having a pale eastern form and a more 
black western form, both of which meet 
in Colorado. This color difference 
has not been satisfactorily explained, 
although it was investigated in some 
detail by Aldrich (1918). Two other 
species, Cl. occidentalis Sehgal , 1968, 
and £. gracilis Spencer, 1969a, are 
known in Alberta and the Yukon, respec- 
tively. Three new species were 
recently described from high mountains 
in Durango Province, Mexico (Spencer, 
1977c). 
Cerodontha (Cerodontha) dorsalis (Loew) 
(Figs. 549-552) 
Synopsis. 3d antennal segment 
elongate, with short spine at upper 
corner (fig. 549); frons, face, and 
gena orange yellow; 3d antennal 
segment black; gena broad, 0.33 height 
of eye; mesonotum either uniformly 
matt grayish black (western form) or 
in typical (eastern) form yellowish 
centrally adjoining scutellum; 3+1 dc, 
acr lacking; scutellum either yellow 
centrally or entirely black; 
notopleural area yellow, pleura 
otherwise dark; legs with femora 
bright yellow; wing length variable, 
2.4-3. 2 mm; male genitalia with aedea- 
gus (figs. 550, 551) having distal 
tubules greatly enlarged at end. 
Hosts/Early Stages. Poaceae, with 
records from following cultivated and 
wild genera: Avena , Bromus , Dactylis , 
Eleusine , Elymus , Hordeum , Pan i cum , 
Phalaris , Phleum , Poa , Secale , 
Triticum , and Zea . Larva is a leaf 
miner, pupating internally in leaf 
sheath; puparium shining, yellow- 
ish brown, somewhat flattened, with 
posterior spiracles irregularly 
branching, each with about 15 minute 
bulbs (fig. 552). 
Distribution. Probably present in all 
States, locally abundant in early 
summer; Brazil, Canada, Central 
America, Mongolia, Puerto Rico. 
References. Luginbill and Urbahns, 
1916 (biology); Aldrich, 1918; 
Spencer, 1969a: 142; 1981: 174. 
Note. As many as eight generations a 
year have been confirmed in southern 
California, and with complete over- 
lapping, all stages can be found 
simultaneously. This species may be 
of some economic importance, with all 
cereal crops serving as hosts. How- 
ever, despite initial damage to young 
plants, they tend to recover and it is 
not certain whether there is any 
reduction in yield (Spencer, 1973a: 
293-296). 
Cerodontha , Subgenus Xenophytomyza Frey 
Cerodontha , subgenus Xenophy t omy z a 
Frey, 1946: 51. Type of subgenus: 
Hap 1 omy z a atronitens Hendel, 1920 
(Europe) . 
This subgenus has in common with 
Cerodontha only one pair of scutellar 
bristles; it was differentiated from 
Cerodontha by Frey (1946) by the lack 
of a spine on the third antennal 
segment and by being entirely black. 
Three species are known in Europe 
(Spencer, 1976a: 180) with the third 
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