
REVISIONARY CLASSIFICATION OF RUTILIINI 23 
are no characters that can be used at the generic level (although differences in the 
shape of the surstyli and cerci can be very important in distinguishing species) and 
genera have to be characterized by externally visible features. Some of the genera 
are moderately distinctive and can be satisfactorily diagnosed, but others need to be 
characterized by aggregates of several features taken together (even then they may 
have to include species which clearly fit them on total facies but which fail to conform 
to one or more of the normal generic characters). It has to be borne in mind when 
using the keys that almost any character can fail in an occasional specimen. 
KEY TO THE GENERA OF RUTILIINI 
[Note : Tasmania is treated as part of Australia and is not separately cited in the geographical 
information. ] 
I Suprasquamal ridge bare (Text-fig. 21). Prosternal membrane bare : 2 
— Suprasquamal ridge haired (Text-figs 23 & 24). Prosternal membrane =e or 
haired (Text-fig. 18) : 7 
2 Palpi minute, not longer than basal width of mentum, and not longer than third 
antennal segment. Buccal opening very long and narrow (Text-fig. 15), at 
narrowest point not wider than facial carina. Arista conspicuously short-plumose. 
Upper parts of parafacials haired. Upper calypter enlarged, when wings folded 
usually as long as lower calypter. [Australia only] 
PRODIAPHANIA Townsend (p. 107) 
— Palpi well developed, very much longer than either basal width of mentum or third 
antennal segment. Buccal opening wide (Text-fig. 14), much broader than facial 
carina (except in Forvmodexia). Arista pubescent or occasionally with very short 
plumosity. Parafacials entirely bare (some exceptions). Upper calypter normal 3 
3 Postalar callus with two strong setae (sometimes with one very much shorter and 
finer setula in addition differentiated from hair). Epistome subnasute, facial 
profile deeply excavate between epistome and carina (Text-fig. 8). Palpi sexually 
dimorphic, distinctly clubbed or spatulate in 2 and slender in g. Infrasquamal 
setulae often present. Scutellum normally with only three pairs of marginal setae, 
at most with four (including the apical pair). [Australia only] 
CHETOGASTER Macquart (p. 112) 
— Postalar callus with three or more strong setae. Epistome not very strongly promi- 
nent, facial profile usually only slightly concave between epistome and carina 
(Text-fig. 4). Palpi not sexually dimorphic, long and slender in both sexes (at 
most only trace of swelling at extreme tip). Infrasquamal setulae absent. 
Scutellum normally with 4-11 pairs of a setae (including apical pair), very 
rare specimens with only three pairs : 4 
4 Apical scutellar setae inserted at the same level as the other ecutellar neampinal sotae 
(Text-fig. 11). Postalar wall with dense hair tuft (Text-fig. 25). Ventral margins 
of abdominal tergites with very strong spiniform setae directed downwards. Head 
often partly metallic. g head sometimes holoptic or almost so. [Java to Solomon 
Islands, Australia] ‘ : . FORMOSIA Guérin-Méneville (p. 25) 
— Apical scutellar setae inserted at a conspicuously lower level than the other scutellar 
marginal setae (Text-fig. 10). Postalar wall without dense hair tuft (except in 
Formodexia). Ventral margins of abdominal tergites without such vestiture, if 
marginal setae slightly spiniform then directed backwards as well as downwards. 
Head non-metallic. g head never holoptic ; 5 
5 Postalar wall with dense hair tuft. Buccal opening very narrow, in rg scarcely at all 
