Eugowra, 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 : 120

Genus Eugowra n.gen.

Etymology. Eugowra , the locale of the type species, is a geographic place name of Australian Aboriginal origin. The gender is feminine.

Type species. Eugowra uniseta n.sp.

Diagnosis. Subfamily Empidinae , tribe Hilarini , with the following tribal characters (Bickel, 1996): laterotergite bare; male basitarsus I enlarged or swollen; costa circumambient; vein R 1 distinctly swollen before joining costa; tibia I with anteroapical comb of 8–10 short even setae; male cercus small and desclerotized, and fused laterally with the surstylus and epandrium.

The genus is characterized by: mesonotum without distinct cuticular patterns or bands; vein Sc incomplete, not upturned to costa; hypandrium reduced to narrow curved channel, joined to epandrium only at base, and which barely covers aedeagus along its length; female TIII slightly flattened laterally, with posterior surface from 1 ⁄ 5 to 5 ⁄ 6 slightly concave and bare of normal short vestiture (FSSC).

Description. (based on three included new species); body length 3.0–3.7. Head ( Fig. 1a): spheroidal with convex postcranium; row of pale postorbitals present, short ventrally, becoming longer dorsally; postcranium with scattered pale setae; post-occiput, vertex, frons and face mostly dark brown and covered with grey pruinosity; setae brown with yellowish reflections; ocellar triangle with 2–3 pairs of posterior setulae, and pair of diverging setae anteriad of lateral ocelli; frons with four strong setae along lateral margin; frons only slightly narrower than ocellar triangle; eyes notched laterad of antennae; face about as wide as frons, covered with grey pruinosity; palp yellow, elongate and curved, and with some long pale ventral setae; proboscis dark brown, slightly curved and stout; labrum brown with some yellow basal areas; scape and pedicel brown, subequal; postpedicel and style black; postpedicel flask-shaped with two-segmented style, and distal segment of style just slightly shorter than postpedicel. Thorax mostly uniform brown or black with grey pruinosity, without distinct mesonotal cuticular or pruinose patterns or bands; thoracic setae mostly yellowish; ac either biseriate or comprising band 3–4 setae wide; dc as row of short pale setae, with 4–6 longer setae along posterior mesonotal slope, and 12–15 setae anteriad; 1 short postalar (pa) seta and row of 4–5 short supra-alar (sa) setae present; 2–3 posterior notopleural (npl) setae, with 4–5 short setulae anteriad; strong sr seta and shorter humeral seta present; some additional setae present on anterior thorax just mediad of humeral callus; pronotum with two pairs of pale diverging setae; prosternum with group of pale hairs; scutellum with 4 pairs of marginal setae. Legs vestiture mostly yellow or brownish; CI with anterior and anterolateral setae; CII with anterior setae; CIII with some weak anterior setae, and 2–3 short lateral setae, and 2–3 posterior setae; tibia I with distinct anteroapical comb of 8–10 short, equal length setae of both sexes; tibia I often with long dorsal setae; male It 1 greatly swollen ( Figs 1b,d,g), female unmodified; femora II and III often with long dorsal and ventral setae; female TIII slightly flattened laterally, with posterior surface from 1 ⁄ 5 to 5 ⁄ 6 slightly concave and bare of normal short vestiture (FSSC). Wing ( Fig. 1e) membrane hyaline; costa circumambient, although reduced in thickness along posterior margin; Sc incomplete, and straight, not upturned to costa; R 1 slightly swollen before join with costa; faint stigma present; costa haired, but other veins bare; R 4+5 branched, R 4 in gentle curve; R 5 straight and ending at wing apex; M 1, M 2, and CuA 1 all joining margin; CuA 2, which closes cell cup, strongly recurrent; A 1 present distally only as fold, and arising midway along cell cup; A 2 present as trace; anal angle weak. Abdomen mostly brown or black with pruinosity; setae longer along posterior margins of each tergum; hypopygium ( Fig. 1c,f); cercus distinct and divided into sclerotized short basal cercal plate and digitiform clasping cercus; epandrium with elongate posteriorly projecting setae; aedeagus elongate and conforming to curvature of hypandrium; hypandrium reduced reduced to narrow curved channel (and with median pointed projection), joined to epandrium only at base, and which barely covers aedeagus along its length; distinct surstylus not evident.

Female oviscapt relatively unmodified, with subequal terga and sterna on segments 9 and 10, and with pair elongate apical cerci projecting posteriorly.

Remarks. Eugowra has a southern temperate distribution in Australia, and is known from lowland sites in Tasmania, Victoria, and southern interior New South Wales. Moreover, adults are decidedly cool-adapted, with all known specimens collected between April and September. Further, mating pairs of E. colei were taken in July, mid-winter in Hobart, Tasmania. It should be noted that southern Australia and Tasmania have more winter-flying Diptera than commonly assumed. There is a distinct bias against winter collecting, and indeed, visible insect activity is much reduced during cold days and frosty nights, especially when compared with the peak activity period from October–January. However, samples from passive traps in western Tasmania (unpublished data), reveal a rich winter Diptera fauna with many undescribed taxa. Mackerras (1950) noted that cooltemperate Australian Diptera (often with Gondwanan affinities) emerge in winter to early spring in the northern part of their range, but later in montane or southern localities. In this light, truly winter fauna, such as Eugowra , are even more likely to be Gondwanan.

Mating behaviour is unknown. However, males have swollen fore basitarsi which probably produce silk for wrapping nuptial gifts, characteristic of the Hilara- Hilarempis complex of genera.