TACHINIDAE OF AUSTRALIA 41 



is insufficiently substantiated at present and the diagnosis of Eutherini given 

 above omits Redtenbacheria from consideration. 



SUBFAMILY PROSENINAE (DEXIINAE) WITH KEYS TO THE 

 TRIBES AND GENERA 



The subfamily name Proseninae is here used in order to conform with the recently 

 published catalogues of the Tachinidae of North and South America, although it 

 is now known that it is not the oldest available name that applies to the group; 

 several family-group names based on included genera pre-date the use of Prosenini 

 (-ae) and one of these ought strictly to be used for the subfamily under the priority 

 requirements of the International Code of Zoological Nomenclature. It is not yet 

 clear which name should stand valid, and most specialists are in favour of returning 

 to the name Dexiinae (that used to be almost universally applied to the subfamily). 

 The name Dexiinae cannot, however, be validly applied to the subfamily until the 

 type-species of Dexia Meigen is changed by a ruling of the International Commission 

 on Zoological Nomenclature; such a ruling has not yet been applied for, although it 

 is under active consideration by interested specialists. 



The subfamily is very large and cosmopolitan and its members appear exclusively 

 to parasitize beetles. There are very few host records for the rich Australian fauna, 

 but it is a reasonable guess on present evidence that all will be found to have 

 coleopterous hosts. Several tribes have been delimited within the subfamily by 

 various authors, notably Townsend, but taken as a whole the multiplicity of forms 

 tends to merge together with few if any breaks in the characters that permit 

 satisfactory tribal definitions. Even between the Rutiliini and the rest of the 

 Proseninae (which are conventionally treated as tribally distinct) there are few 

 concrete characters that absolutely serve for reliable tribal discrimination (Crosskey, 

 1973) of all the forms into one tribe or the other; the genus Chetogaster Macquart 

 could, for example, be equally well placed in either the Prosenini or the Rutiliini 

 (in the present work it is retained therefore in its traditional position in the latter 

 tribe). 



As with other tachinid subfamilies it is difficult to formulate a fully satisfactory subfamiliar 

 definition but the main characteristics of most members of the group are as follows. Head 

 often with a very strong facial carina separating the antennae or with a sharp median ridge 

 (though carina lacking in very many forms) ; rows of frontal setae descending to the level of 

 the lunula or the first antennal segment; ^ without reclinate orbital setae; $ head often with 

 eyes very strongly approximated but not holoptic (except in a few Formosia species) ; uppermost 

 eye facets normally not enlarged (only enlarged in some Formosia) ; eyes bare [this is true 

 of almost the entire vast complex of world forms included in the Proseninae, but there are 

 a very few exceptions that have haired eyes: examples, Callotroxis Aldrich and Tyreomma 

 Brauer and Bergenstamm from South America] ; inner vertical setae when present often 

 convergent or crossing ; presternum bare (except in a few Rutiliini) ; prosternal membrane 

 bare (except in some Rutiliini) ; humeral callus with at least two setae distinguishable (though 

 these may be very weak in Rutiliini); post ia setae varied, from none to four; dorsocentral 

 setae varied, often very reduced in Rutiliini, pre-alar seta weak or absent; two or more 

 differentiated sa setae in almost all forms; postalar callus with 2-7 setae; usually two or 

 three sternopleural setae (one or none in some Rutiliini) ; infrasquamal hairs nearly always 



