To identify N. gracilis and N. atricauda sp. nov. 1a. Large, slender body (total length: ca. 10–13 mm); bright orange colouration......................................... 1b. - Size small to large (total length: ca. 4–9 mm; rarely larger), slender to more robust; body colouration vari- able, never bright orange ...........................................................................................................................1c. 1b. Scutum and scutellum with board, grey, pubescent stripe; female abdomen uniform orange colour ........... ............................................................................................................................................ gracilis (Mann). - Scutum and scutellum without grey pubescent strip; female abdomen orange with segments 7–8 and ter- minalia black ..................................................................................................................... atricauda sp. nov. 1c. Epandrium without enlarged setae (e.g. Winterton et al. 1999a: fig. 30); female abdominal tergite 2 with- out patch of modified setae......................................................................................................................... 2. - Epandrium with enlarged setae laterally or posterolaterally (e.g. Winterton et al. 1999a: figs 101, 119, 147); female abdominal tergite 2 usually with patch of modified setae posteromedially (Winterton et al. 1999a: fig. 17c, d) ................................................................................................... palassa species-group 3.

Published as part of Winterton, Shaun L., 2007, New species of Nanexila Winterton & Irwin and Taenogera Kröber from Australia (Diptera: Therevidae), pp. 55-64 in Zootaxa 1413 on page 60, DOI: 10.5281/zenodo.175680