Nanexila Winteron & Irwin

Nanexila Winterton & Irwin, 1999a: 244. Type species: Anabarhynchus manni Hardy, 1955: 178.

Could be confused with: Actenomeros, Neodialineura, undescribed genus 'N'.

Systematic grouping: Taenogera genus-group.

Diagnosis: Antennae positioned low on frons; scape much shorter than flagellum; frons slightly rounded; male occiput concave, single row of postocular setae in male, 2-3 poorly defined rows in female; wing cell m3 open; anteroventral apical seta present; fore and hind femora without velutum patches; gonocoxites shape variable, medial atrium absent; aedeagus with dorsal apodeme of parameral sheath usually T-shaped; anterior process of female tergite 8 broad; three spermathecae; spermathecal sac highly variable, often complex.

Distribution: Australia-wide; particularly species-rich in southern Australia.

Comments: Nanexila contains three species groups (N. manni, N. palassa and N. atricostalis species-groups). The genus is difficult to diagnose relative to other Taenogera genus-group genera as this genus lacks easily recognisable autapomorphic characters. A number of undescribed species are present in collections and once these are described the genus may require further subdivision. The highly variable and often complex spermathecal sac shape in females throughout this genus is the most dramatic of that found in any therevid genus (see Winterton et al. 1999a). Spot characters to look for when identifying this genus include velutum patches on the fore and hind femora absent, wing cell m3 open, antennae short, frons flat, apical setae on hind femur, three spermathecae.

Included species: N. argentiquadris Winterton & Irwin, N. armeniacum Winterton & Irwin, N. atricostalis Winterton & Irwin, N. aureilineata Winterton & Irwin, N. carminata Winterton & Irwin, N. cylomelasma Winterton & Irwin, N. danielsi Winterton & Irwin, N. furcata Winterton & Irwin, N. gracilis (Mann, 1928), N. intermedia Winterton & Irwin, N. lignyos Winterton & Irwin, N. ligula Winterton & Irwin, N. livea Winterton & Irwin, N. lutea (White, 1915), N. manni (Hardy, 1955), N. nana Winterton & Irwin, N. palassa Winterton & Irwin, N. paradoxa Winterton & Irwin, N. rufa (Kröber), N. ruficornis (Macquart, 1850), N. spilotis Winterton & Irwin, N. variabilis Winterton & Irwin, N. vittata Winterton & Irwin.

Relevant Literature:
Hardy, G.H. (1955) The Diptera of Katoomba Part I.-Therevidae. Proceedings of the Linnean Society of New South Wales, 80, 177-179.

Macquart, J.M. (1850) Diptères exotiques nouveaux ou peu connus. 4.e supplement. Mémoirs de la Société Royale des Sciences, de l’Agriculture et des Arts, de Lille, 1849, 309-479.

Mann, J.S. (1928) Revisional notes on Australian Therevidae. Part 1. Australian Zoologist, 5, 151-194.

Metz, M.A., Webb D.A., & Irwin M.E. (2003) A review of the genus Psilocephala Zetterstedt (Diptera: Therevidae) with the description of four new genera. Studia Dipterologica 10: 227-266.

White, A. (1915) The Diptera-Brachycera of Tasmania. Part II. Families Tabanidae and Therevidae. Papers and Proceedings of the Royal Society of Tasmania, 1915, 2-60.

Winterton, S.L., Irwin, M.E. & Yeates, D.K. (1999a) Systematics of Nanexila gen. nov. (Diptera: Therevidae) from Australia. Invertebrate Taxonomy 13: 237-308