A revision of the oriental Euscelidia Westwood, 1850 (Diptera: Asilidae: Leptogastrinae)

Euscelidia Westwood, 1850 is a genus in the subfamily Leptogastrinae of Asilidae (Diptera).  It is distributed throughout the Afrotropical and Oriental regions, with a few species in the southern Palearctic region.  Like other Leptogastrinae, it is small, elongate and slender, but it can be distinguished from other genera by its only autopomorphic feature, the presence of a postpronotal peg anterior to the thorax.  As it currently stands, the genus contains 68 species: 55 Afrotropical, 11 Oriental and 4 Palearctic, with two species occurring in both the Afrotropical and Palearctic regions.  Euscelidia was exhaustively revised in Dikow, 2003, however since then new material not available at the time of his revision has been obtained, particularly of species from the Oriental region.  This material required a further update of the genus in order to incorporate them.  Additionally, we find five species described in either Ammophilomima or Leptogaster that need to be newly combined with Euscelidia.  We build on the framework provided in Dikow, 2003 and reexamine the Oriental Euscelidia.  We update the descriptions for existing published taxa and describe 44 new species from India, Sri Lanka, Malaysia, Thailand, Indonesia and Vietnam. We also expand the genus to the Australasian region, with the description of a single species from Papua New Guinea. To produce this analysis, external morphology was examined and male and female terminalia were dissected and compared when available.  We include with these descriptions an updated identification key to the Oriental and Australasian species of Euscelidia and additionally discuss the distribution and seasonality of each species.