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TACHINIDAE OF AUSTRALIA 63 
[The Eurasian and African genus Steiniomyia Townsend runs here and has all 
the essential characters of Hyleovus. It should be treated as a synonym of the 
latter, but definite synonymy is not established at this time] 
— Prosternum bare. Eyes bare or almost completely so. MM, spur vein or fold short, 
not nearly as long as the section of M between m-—cu and the bend (Text-fig. 82). 
One or both intermediate abdominal tergites without discal setae. Facial ridges 
bare (except for the usual very few setulae immediately above the vibrissae) 
HYSTRICOVORIA Townsend 
[The Ethiopian and Oriental genus Afrovovia Curran (synonym Anavoria 
Mesnil) runs here and has all the essential characters of Hystricovoria. It should 
probably be treated as a synonym of the latter, but definite synonymy is not 
established at this time] 
Tribe THELAIRINI 
This is a small but widely distributed tribe occurring in both Old and New Worlds. 
The type-genus Thelaiva is found throughout the Palaearctic and Oriental Regions, 
Africa and Madagascar, in New Guinea and in eastern Australia south to Tasmania, 
and in the New World occurs southwards as far as Mexico; in the Pacific area the 
genus is apparently unrepresented eastwards of New Guinea. The only genus found 
so far in Australia, other than Thelaiva, is Halydaia, a very distinctive form occurring 
in most of the Oriental Region eastwards to Japan, the Ryukyu Islands, New 
Guinea, the Solomons and Australia (excluding Tasmania); at least one rare species 
of Halydaia occurs also in western Europe. In the Old World Halydaia appears 
to be rather disjunct from other thelairines, but the genus appears to be rather 
closely related to the Neotropical genus Xanthodexia Wulp (syn. Minthodexia 
Brauer & Bergenstamm) which is somewhat intermediate between Halydaia and 
the more typical Thelairini. 
The chief characteristics of the Thelairini are as follows. Eyes bare or virtually so (some 
very minute hairs can sometimes be made out under high power examination); parafacials 
bare; eyes extremely large and filling most of the sides of the head, gena correspondingly 
very reduced and without a definite genal dilation (eyes coming so far down on the head 
that the lowest point is usually below the level of the vibrissae); face and epistome flat, latter 
invisible in profile; vibrissae usually level with epistomal margin (above the level in the 
Oriental genus Prosheliomyia Brauer & Bergenstamm); antennae small or very small (length 
less than half of eye-height) and antennal axis at or below level of eye middle; arista usually 
short plumose or long plumose, sometimes pubescent; proboscis very short, mentum convex 
on lower edge in profile, palpi well developed (a little flattened); prosternum, prosternal 
membrane, and propleuron bare; two sternopleural setae (rarely three in 9); 3 + 3 dc setae; 
pre-alar seta very small; two or three fost ia setae (rarely specimens may have only one); 
infrasquamal hairs usually absent; scutellum with three pairs of very strong marginal setae 
(basals, subapicals, and strong crossed horizontal apicals); pteropleural seta absent (except 
in Prosheliomyia in which weak pteropleural always evident); fore coxa largely bare or fully 
haired on inner anterior surface; mid tibia with a v seta; hind coxa bare posterodorsally; 
hind tibia without a pv apical seta; upper surface of wing setulose at least on R,,; half way 
to y-m, often veins FR, and Cu, extensively setulose (ft, setulose along all its length in both 
genera occurring in Australia); cell R; open to the wing margin; bend of vein M moderately 
sharp or rather evenly rounded, usually without M, appendix; second costal sector haired 
ventrally; excavation of Ti + 2 variable, usually not quite reaching hind margin of tergite; 
