12 R. W. CROSSKEY 



visible when fly seen in profile. [Hosts unknown in Oriental Region, elsewhere 

 Orthoptera Tettigonioidea and Grylloidea] . . Ormiini (Tachininae, part) (p. 62) 



3 Face produced into a heavy bulbous or flattened, ridge-like or roof-like, facial 



carina that extends from the antennae to the epistome (the carina entirely or 

 largely visible in profile, e.g. as Text-figs 27, 28, 30, 31, and often separating 

 deeply excavated antennal foveae). Eyes bare ...... 4 



- Face not produced into a definite facial carina, usually either flat or sunken and 



invisible or mainly so in profile (occasionally faintly ridged medially, especially 

 on upper part, but not so as to separate deep recesses for the antennae). Eyes 

 bare or haired ............ 6 



4 Wings with a double transverse black band in the apical half (Text-fig. 90). 



Antennal axis above level of eye-middle and antennae very long (reaching at 

 least to epistomal margin, Text-fig. 27). Genal depth much less than length 

 of third antennal segment. Facial carina in the form of a broad swelling of 

 the whole face that is sharp in the mid-line. Arista bare. [Parasites of Hemiptera 

 (Pentalomidae)] ...... Eutherini (Phasiinae, part) (p. 34) 



- Wings without black-banded pattern. Antennal axis at or below (usually well 



below) level of eye-middle and antennae short or very short (not reaching 

 epistomal margin) (Text-figs 28-31). Gena very large in relation to the eye, 

 its depth nearly as great as the length of the third antennal segment or of the 

 whole antenna (Text-figs 28-31). Facial carina forming an abrupt ridge or 

 platform that is convex or flattened on its anterior surface, sometimes bulbously 

 tuberculate, often fusiform in outline but rarely sharpened in mid-line. Arista 

 plumose or conspicuously pubescent (Text-figs 28-31) ..... 5 



5 Lower calypter with the posterior outline evenly rounded, diverging from the 



scutellum and lacking an abrupt inner posterior angulation. Abdominal Ti + 2 

 not excavate to its hind margin. Head of both sexes holoptic or virtually so. 

 $ postabdomen exserted and with paired black sclerotized dorsolateral pliers-like 

 lamellae (sometimes bearing recurved hooks). [Hosts unknown] 



Imitomyiini (Dufouriinae, part) (p. 41) 



- Lower calypter broad and with a definite angulation of the inner posterior part of 



its outline that is close to the scutellum. Abdominal Ti + 2 excavate to its 

 hind margin (except in Dexiotrix). Head sometimes nearly holoptic in o*< 

 dichoptic in $. $ postabdomen not exserted. [Parasites of larval Coleoptera] 



PROSENINAE (DEXIINAE) (part) (p. 43) 



6 Prosternum haired or setose (care required : sometimes only one hair on each side) . 7 



- Prosternum bare ............11 



7 Eyes hairy (the hairing long and easily visible in silhouette at low magnifications) . 8 



- Eyes bare or nearly so (hairing if present very short and sparse and only visible 



at high magnifications) . . . . . . . . . .10 



8 Metallic green or bluish green flies (from Palaearctic border areas). [Hosts unknown 



in Oriental Region, elsewhere Lepidoptera] Ernestiini (part) (Tachininae, part) (p. 95) 

 [At this exit runs out the genus Chrysosomopsis which is the only Oriental 

 member of Ernestiini with haired prosternum. This feature occurs in all 

 specimens seen but it is possible that individuals with bare prosternum occur. 

 If so they will run out to Tachininae elsewhere in the key.] 



- Non-metallic flies never green or blue green (if slightly metallic then dark blue-black) 9 



9 Wing as in Text-fig. 92, M x very strongly oblique and M 2 appendix very long, vein 



i? 4+5 setulose on most of its length. Frons of both sexes equally very wide and 

 with a row of from 3-5 strong proclinate orbital setae. Disc of scutellum with 

 a pair or more of erect setae. Pteropleural seta very weakly differentiated. 

 [Parasites of Lepidoptera] .... Voriini (part) (Tachininae, part) (p. 65) 



[At this exit runs out the genus Hyleorus which is the only Oriental member 



of Voriini with haired prosternum] 



