TACHINIDAE OF ORIENTAL REGION 43 



Key to Oriental Genera of IMITOMYIINI 



[Note. Imitomyia is included although not known from the Oriental area.] 



Proboscis not longer than the height of the head, non-geniculate and with short 

 dilated labellae. Two post ia setae. Arista plumose. Abdominal tergites with 

 some long but very fine marginal setae clearly differentiated. [Eastern Asia] . . 2 



Proboscis very attenuate, much longer than head height, the labellar part not dilated 



and usually geniculated from the preceding part. One post ia seta. Arista with 



short or long pubescence but not plumose. Abdominal tergites with uniformly 



hair-like vestiture (the marginal hairing at most only slightly stronger than the 



rest). [Europe, Africa, North America] .... IMITOMYIA Townsend 



[The little-known European genus Himantostomopsis has not been seen but will 



probably run here. It differs from Imitomyia by having the parafacials haired 



and is of doubtful validity.] 



Wing cell R b with a very long petiole. One supra-alar seta. Dorsal lamellae of $ 

 terminalia bearing strong recurved preapical spines. Parafrontals meeting in the 

 mid line of the frons and obliterating the upper part of the interfrontal area. 

 Ocellar setae undeveloped, ocelli very prominent . . PRORIEDELIA Mesnil 



Wing cell i? 5 narrowly open or just closed in the wing edge. Two supra-alar setae (a 

 very small second sa seta present). Dorsal lamellae of 9 terminalia without spines 

 but with some long setulae. Parafrontals approximated but not meeting in the 

 mid-line of the frons, upper part of interfrontal area therefore not completely 

 obliterated. Ocellar setae differentiated but long and fine, ocelli not strikingly 

 prominent RIEDELIA Mesnil 



SUBFAMILY PROSENINAE (DEXIINAE): KEYS TO THE TRIBES 



AND GENERA 



This is the subfamily most conventionally known as the Dexiinae. In the 

 interests of stability it should continue to be known by this name, but it is not 

 strictly correct under the rules of nomenclature. For preference the name Proseninae 

 is used here in conformity with recent works such as those of Sabrosky & Arnaud 

 (1965) and Crosskey (1973a; 19736), but as I have pointed out elsewhere (Crosskey, 

 19736 : 41) even this is not really the valid family-group name since several other 

 family-group names based on included genera have priority over the family-group 

 name based on Prosena, for example both 'Rutiliidae' and 'Amphiboliidae' of 

 Brauer & Bergenstamm (1889) pre-date the first use of 'Proseninae' (by Townsend, 

 18926). Unfortunately the nomenclatural problem is confounded by a taxonomic 

 one, since many specialists now hold the view (not yet formalized in publication) 

 that the subfamily limits should be widened to embrace forms hitherto placed in 

 the Dufouriinae or the Tachininae. Change in the taxonomic concept implies, 

 nomenclaturally, that a change should be made in the subfamily name - because, 

 for example, a family-group name based on Dufouria Robineau-Desvoidy appears 

 to be as old as or older than any other name that could be applied to the extended 

 subfamiliar concept ('Dufouridae' dates from Robineau-Desvoidy, 1830). The 

 most practical and commonsense course will be to call the subfamily by the name 

 Dexiinae (once the type-species of Dexia Meigen is re-fixed by the International 

 Commission on Zoological Nomenclature: see discussion under Prosenini), because 

 of its almost universal use, even though it will not be the oldest applicable family- 



