Eugowra fusca, Daniel J Bickel, 2006

Daniel J Bickel, 2006, Eugowra, A New Fly Genus from Australia (Empididae: Empidinae), Records of the Australian Museum 58, pp. 119-124 : 123-124

Eugowra fusca n.sp.

Type material. HOLOTYPE 3, PARATYPE ♀, Victoria: Darriman, 22.vii.1952, G.W. Douglas (MVM).

Additional material. Victoria: 3, Ocean Grove, 5.viii.1960, J. Martin (MVM).

Description. Male length 2.7; wing 3.7× 1.3. Head mostly black with some grey pruinosity; orbitals short, becoming longer dorsally; face bare of setae. Thorax dorsally black, mostly shiny with some grey/brownish pruinosity; pleurae covered with grey pruinosity; ac short, biseriate. Legs Coxae yellowish to brownish and covered with grey pruinosity; femora mostly yellowish; TI and TII yellowish basally but becoming dark brown distally, TIII dark brown; tarsi dark brown or black; I: 3.5; 3.2; 1.8/ 0.4/ 0.3/ 0.3/ 0.5; ( Fig. 1g) TI with row of dorsal setae with some outstanding longer setae on distal half, especially at 7 ⁄ 8 (MSSC); It 1 swollen with shaggy appearance from dorsal and lateral hairs (MSSC); II: 4.3; 4.0; 1.2/ 0.3/ 0.3/ 0.2/ 0.5; FII with rows of av and pv hair-like setae; TII with some dorsal setae, slightly increasing in size towards the apex; IIt 1 not swollen but with some dorsal setae; III: 4.7; 4.7; 1.5/ 0.7/ 0.4/ 0.3/ 0.6. Wing distinctly smoky; brownish stigma present; halter with brownish stem and brown club. Abdomen dark brown with brown to dark brown setae and the posterior margins of the terga have longer hairs; hypopygium not figured, but median basal projection of narrow and pointed, similar to Fig. 1c. Female similar except as noted; TI and TII without strong dorsal setae; It 1 unmodified.

Remarks. Eugowra fusca is known from two locales in southern Victoria: Gippsland, and the Geelong district. Specimens were collected in winter months, July and August.

Notes on morphology and systematic position of Eugowra

With the large number of undescribed hilarine taxa, both in Australia and throughout the world, it is premature to attempt any phylogenetic analysis of the tribe. However three morphological characters related to Eugowra should be discussed.

1 Vein Sc: complete/ incomplete. The plesiomorphic condition is considered to be Sc complete and fusing with the costa, with varying degrees of reduction (“incompleteness”) being derived. However, this character is variable throughout the Empidinae , and the incomplete Sc is probably homoplasious, and possibly is subject to reversal.

2 Female tibia III: unmodified/ flattened laterally, and with posterior surface from 1 ⁄ 5 to 5 ⁄ 6 faintly concave and bare of normal vestiture, but with fine pile. This modification also occurs in many species of Australian Hilara s.l.. This modification functions in aerial display and species recognition, as the fine hairs of the pile appear to have a reflective function, and on some of the Hilara species the hairs are silvery.

3 Hypandrium: forming curved hood joined to epandrium and completely covering aedeagus/reduced to a narrow curved channel which is distally free from the epandrium, and which barely covers the aedeagus along its length.

In the Hilarini , the hypandrium usually forms a curved convex hood covering the aedeagus along the distal hypopygial margin to the surstylus. By contrast, in the tribe Empidini the hypandrium is often highly reduced and covers only the aedeagal base, leaving body of the aedeagus exposed and free (e.g., see figures of Empis species in Chvála, 1994).

At first glance, Eugowra also appears to have a free aedeagus. However, closer examination shows the hypandrium has been reduced to a narrow curved gutter which follows and barely covers the aedeagus along its length parallel to the distal hypopygial margin. This unique autapomorphy defines Eugowra as a monophyletic group.

Needless to say, the relationship of this genus to the rich and disparate Hilara-Hilarempis complex of species is not clear. I have decided to give these three species generic status rather than assigning them to a species group or subgenus in either of the two poorly defined genera, Hilara or Hilarempis . At least Eugowra is clearly defined by a distinct suite of synapomorphies, and its ultimate phylogenetic position can be defined in the future.

ACKNOWLEDGMENTS. I thank the following institutions and their curators for loan of specimens: ANIC, Australian National Insect Collection, CSIRO, Canberra, P. Cranston; MVM, Museum of Victoria, Melbourne, K. Walker. S. Bullock and H. Finlay drew the figures. This research was supported by Australian Research Council grant A19232651, for study of the systematics of Australian Empidinae . B. Sinclair provided useful comments on an earlier manuscript version of this paper.