Ceratomerus albistylus Hardy, 1930

Bradley J Sinclair, 2003, Taxonomy, Phylogeny and Zoogeography of the Subfamily Ceratomerinae of Australia (Diptera: Empidoidea), Records of the Australian Museum 55, pp. 1-44 : 33-35

Ceratomerus albistylus Hardy

Figs. 61, 62, 85, 93, 95, 96, 110–112, 118

Ceratomerus albistylus Hardy, 1930: 246 ; Smith, 1989: 387. C. albistilus Hardy, 1930: 245 , 246 (mis-spelling). C. tuberculus Hardy, 1930: 247 ; Smith, 1989: 387.

Notes on spelling and synonymy. Ceratomerus albistilus was spelt originally as such by Hardy (1930) in both his key and description, but was spelt albistylus when compared to another species ( C. ordinatus ) taken at the same locality. This species was subsequently spelt albistylus in the Zoological Record and Smith (1989).As first reviser (I.C.Z.N. 1999, Sec. 24.2.3), I have chosen to maintain the spelling as used by Smith (1989) in order to avoid further confusion.

The description of C. albistylus was based only on female specimens and C. tuberculus on males. On the basis of similar colour patterns Smith (1989) synonymized these two species and I can confirm this nomenclatural change.

Type material. NEOTYPE (here designated) 3, “Mt.

Wellington / Tas [mania, Australia]/ 12 Feb. 1963 / D.H. Colless ”; “Wet forest/ (lower slopes) [dissected]” ( ANIC) .

My neotype label “ NEOTYPE / Ceratomerus / albistylus Hardy / des. B.J. Sinclair 2000 [red label]” has been attached to this specimen.

The syntypes of C. albistylus (type localities: Mt. Wellington, Strahan and Cradle Mountain) and C. tuberculus (type locality: Mt. Wellington) were not located and are presumed destroyed as discussed under C. inflexus . No specimens of these species were mentioned in the list of damaged Hardy types by Daniels (1978). The male specimen selected as neotype agrees with the original description and is from the same locality as the original material described by Hardy. The designation of a neotype clearly establishes the identity of this species.

Additional material. Australian Capital Territory: 2♀♀, Blundell’s , 13.xi.1938 ( ANIC) . New South Wales: 233, 2♀♀, Belmore Falls, 23.i.1963; 833, 8♀♀, Brown Mt., Rutherford Ck , 10.iii., 11.xi.1961; 2♀♀, Bulli , Cataract Ck , 2.xi.1960; 233, 1♀, Clyde Mt. , Landslip , 22.ii.1965; 13, Fitzroy Falls , 22–27.xi.1937; 2 33, 1♀, Kangaroo Valley , west slope, 23.xi.1960; 13, 2♀♀, Macquarie Falls , 14.xi.1960, 13.x.1986; 3♀♀, New England NP, Point Lookout , 30°29'S 152°25'E 12.ii.1984 ( ANIC) ; 533, 1♀, Blue Mtns NP, Blackheath, Popes Glen , dry scler. for., 31.x.1994; 233, 1♀, Blue Mtns NP, Grand Canyon , rainfor., 25.xii.1993 ( ZFMK) ; 1♀, Blue Mtns NP, below Govett’s Leap , 7.xii.1956; 13, 1♀, Gloucester Tops, Nothofagus , 1290 m, 14.xi– 4.xii.1988; 233, 3♀♀, Minnamurra Falls, 7.i., 20.x.1961; 13, Mt. Dromedary , summit , 800 m, rainfor., 9.xi.1985; 13, Nadgee SF, Maxwell’s Ck, warm temp. rainfor., 400 m, 13–19.ii.1987; 2 33, New England NP, Thungutti Rest A., Nothofagus , 20–22.xii.1994; 1 ♀, New England NP, Wright’s Lookout , 1.iv.1961; 2 33, Werrikimbe NP, Cobcroft Ck , 1110 m, 6.xii.1986 ( AMS) ; 533, 19♀♀, Blue Mtns NP, Mt. Wilson, rainfor., Waterfall Ck , 19.xi.1921, 5.xii.1956, 28.xi., 11.xii.1959, 30.xii.1960, 5.xi.1977, 23.xi.1982, 8.xii.1986, 10.xi.1990, 22.xi.1993, 12–13.xii.1998 ( AMS, ANIC, CNC, ZFMK) ; 1 ♀, New England NP, Toms Cabin, 30°30'S 152°24'E, 12–22.ii.1984 (ANIC-alc.); 333, Wentworth Falls, Jamison Ck , 4.xii.1956, 10.xi.1993 ( AMS, CNC) . Tasmania: 6♀♀, same data as neotype; 2♀♀, Adventure Bay, 18, 20.xii.1922; 13, 2♀♀, Cradle Valley, 12–16.ii.1923; 4 ♀♀, 9 km WSW Derwent Bridge, 42°10'S 146°08'E, 21.i.1983; 2♀♀, King River , 4.ii.1923; 1♀, Mt. Field NP, Russell Falls , 23.ii.1967; 2♀♀, National Park , 15–16.xii.1922; 4 33, 5♀♀, 5 km ESE Redpa, 42°57'S 144°49'E, 18.i.1983; 1♀, Lk. Margaret , 3.ii.1923; 233, 2♀♀, 10 mi E Strahan, 7.ii.1967 ( ANIC) ; 1♀, Arthur Plains, 3.ii.1965; 1♀, Sir John Falls, Cataract Ck, trib. Gordon R., 9.i.1977; 2♀♀ , Tasman Peninsula, Pirates Ck, 2.5 km SW Eaglehawk , 13.ii.1990 ( MVM) ; 10♀♀, Arve R. nr Geeveston, 20.i.1960; 6♀♀, Arve R. nr Hartz Mtn Rd. , river rocks, 22– 23.i.1989, y.pans; 13, 1♀, Corinna , 8.i.1960; 1♀, 16 mi NE Cradle Mtn , 2200 ft, 5.i.1960; 2♀♀, Ferntree nr Hobart, 12.i.1960; 1♀, Junee Caves, nr Maydena, 13.i.1960; 1♀, Lyell Hwy, Double-Barrel Ck, rainfor., y.pans, 27.i.1989; 13, 6♀♀, Lyell Hwy, Franklin R. Crossing, 16.i.1960; 8♀♀, Marakoopa Caves, nr Mole Ck, 10.i.1960; 6♀♀, Mt. Barrow , 25–3000 ft, 24–25.i.1960; 4 ♀♀, Mt. Field NP, Lady Barron Ck , 900 m, y.pans, subalpine, 25.i.1989; 1♀, 2 mi S Oonah, Waratah Hwy , 7.i.1960; 1♀, Scotts Peak Dam Rd & Clear Ck, wet scler., MT, 4– 5.ii.1989; 1♀ , Tasman Peninsula, Long Bay Ck, wet scler., y.pans, 7– 9.ii.1989; 3♀♀, Zeehan-Renison Bell SR, N. Zeehan , rainfor., 28.i.1989 ( AMS) ; 7♀♀, Eaglehawk Neck, 17–22.xi.1922, 17.i.1960; 8 ♀♀, Hellyer R. Gorge, S. Wynyard , rainfor., 2–3.ii.1967, 29.i.1989 ( AMS, ANIC) ; 4♀♀, Lyell Hwy, Franklin / Gordon Wild Rivers NP, Surprise R. 19.ii.1994 ( CNC) ; 15♀♀, Pelion Hut , 3 km S Mt. Oakleigh, 860 m, 41°50'S 146°03'E, 5–10.ii.1990, 8.i–12.ii.1991, 6–11.iii.1991 ( ANIC) ; 2 ♀♀, Rd C 405, 12 km N of C401, small ck, 23.ii.1994 ( ZFMK) ; 1♀, Rosebery , ii.1977 ( BPBM) ; 1♀, 4 km E Rosebery , 41°47'S 145°35'E, MT, 16.i– 1.ii.1983; 1♀, 42°43'S 145°49'E, rainfor, 3.ii.1978 (ANIC-alc.) . Victoria: 933, 5♀♀, Acheron Ck, 29 km from Warburton , y.pans, 400 m, 1– 3.xii.1994 ( AMS, ZFMK) ; 1♀, 10 mi E Beech Forest, 1.i.1967; 13, Cabbage Tree Ck, 18.xi.1964; 233, Nowa Nowa, 28.x.1961; 13, Spring Hill Junction, 9 mi N Dargo , 4000 ft, 13.ii.1965 ( ANIC) ; 13, Belgrave, 20.i.1930; 1♀, 8 km SSW Gellibrand, Upper Carlisle R., 27.i.1982; 13, Noorinbee, 12.xi.1969 ( MVM) ; 13, Donna Buang Rd, 15.xii.1970 (ANICslide); 1433, 5♀♀, Errinundra Plateau, Result Ck Falls & Gap Rd , 900 m, 6–7.xii.1994 ( AMS, CNC, ZFMK) ; 1 ♀, Grampians NP, Delley’s Dell , 4 km SSW Halls Gap, 37°11'S 142°31'E, 30.xi.1992; 1♀, Result Ck & Gap Rd , 920 m, cool rainfor., y.pans, 17.i.1991 ( AMS) ; 2♀♀, NNE Melbourne , 20.xii.1960 ( BPBM) ; 233, 5♀♀, Otway NP, Maits Rest , temp.rainfor, ck, 4–5.xii.1994 ( AMS, ZFMK) ; 1 ♀, Otway Ra., Beauchamp Falls , Nothofagus , 3.xii.1994; 333, Otway Ra., Melba Gully SP, temp. rainfor., ck, 4.xii.1994 ( CNC) ; 533, 2♀♀, 9 km N Warburton, Cement Ck , 27.x.1961, 7.iv.1963, 1–3.xii.1994 ( AMS, ANIC, CNC) .

Diagnosis. Recognized by its dark, shiny abdomen, bright yellow legs, white tipped female stylus and greatly lengthened male antennae, with inconspicuous stylus.

Description. Wing length 3.7–4.2 mm, similar to C. attenuatus except as follows:

Male. Head dark brown, shiny, with white pruinescence; ocellar triangle with 2 closely spaced, divergent bristles, inserted between lateral ocelli; postocular bristles very short and fine. Antenna with scape two-thirds height of eye, with many short dorsal setae and 1 long ventral seta ( Fig. 61); pedicel with 1 long dorsal seta. Postpedicel greatly lengthened to 3× height of head, gradually tapered; apical stylus very short, inconspicuous. Palpus yellow, slender, one-sixth length of labrum, with several dark setae.

Thorax. Mesonotum and postnotum dark brown, shiny; pleura shiny, proepisternum, anterior portion of anepisternum, and postpronotal lobe yellow; scutum with median vitta of pruinescence; lateral margin of scutum, prescutellar depression and postnotum with patch of pruinescence. Alternating row of short acrostichals to prescutellar depression, directed posteriorly; 4 dc, third dc stout and long, with setulae intermixed; 4 sctl, outer pair short, slender. Antepronotum with 2 short setulae.

Wing ( Fig. 85). Single short costal seta. R 2+3 not deflected around stigma; radial fork bell-shaped; stem of median fork sometimes nearly twice length of crossvein dm-cu; media1 fork proximal to radial fork by less than length of R 4. Halter with yellow knob.

Legs. Coxae, femora and tibiae bright yellow, hind femur darker towards tip; tarsi becoming dark towards tip. Fore coxa less than twice length of mid coxa. Fore femur slender, with av row of dark slender setae. Fore tibia nearly equal in length to femur. First tarsomere subequal in length of fore tibia; distal 4 tarsomeres slender, subequal in length to first tarsomere.

Apical third of mid femur strongly constricted with posterior projecting lip; 1 long av and 2 long pv setae near mid-length. Mid tibia with projecting appendage corresponding to constriction on femur; appendage with spherical apex and subapical seta ( Fig. 95); pad-like swelling at midlength and apex of tibia ( Fig. 93). First tarsomere longer than remaining 4 tarsomeres, with long curved ventral seta at base.

Hind femur often with long preapical av setae. Hind tibia longer than femur, apex slightly dilated, bearing posteroapical comb; apical half with several erect ad setae; long, slender erect setae often present beneath.

Abdomen shiny, dark brown, T1–5 with short posteromarginal setae; T6 with long posteromarginal setae; T7 pale; S7 slightly longer than preceding sternite; T8 with narrow, posterior incision; posteromargin of S8 with long, stout setae, often extending beyond terminalia.

Terminalia ( Figs. 96, 110, 111). Hypandrium with long posterior flap-like process; postgonites sickle-shaped, with twisted, hooked tips; posteromargin with fringe of long setae, often stout. Phallus with pair of strongly arched processes, curving around flanking postgonites. Posteroapical margin of epandrium with patch of spine-like setae; epandrial lobe slender, with sparse setal fringe and dense crown of setae. Surstylus long and slender, with posterior fringe of dark, stout setae. Cercus thinly sclerotized, short, apex acute, expanded laterally around anus; posterior margin thickly sclerotized.

Female. Similar to male and female of C. attenuatus except as follows: palpus brown. Postpedicel more strongly attenuated ( Fig. 62), with apical fourth white. Halter dark. Lateral margin of S7 straight. Terminalia ( Fig. 112): anterior half of T10 with several rows of stout, curved spine-like setae; cercus with row of short spine-like setae, similar to T10. Spermathecal receptacle spherical, with short ridgelike neck where duct attached.

Distribution. Widespread in southeastern Australia, this species is known from throughout Tasmania, westward to the Grampians in Victoria and north to New England National Park in northern New South Wales ( Fig. 118). Most common at southern latitudes, and confined to higher elevations north of Sydney.

Biology. This species is commonly collected by sweeping riparian vegetation and rarely swept from emergent rocks in streams. Occasionally specimens are found quite distant from running water.

Remarks. Three differing morphological forms can be somewhat identified. Populations in Victoria (Warburton/ Cement Creek region and Otway Ra.), can be distinguished by the absence of a posteromarginal fringe of setae on the hypandrium, and presence of long, slender setae on the apical fourth of the male hind femur and ventral region of the male hind tibia. A northern population is also distinguishable, ranging from Gloucester Tops north. This population is distinguished by the very stout setal fringe on the hypandrium, and the hindlegs also possess long erect setae as in the form known from Victoria. The typical form (widespread, ranging from Tasmania, Victoria and southern NSW), possesses a long setal fringe on the hypandrium and lacks long, slender setae on the male hindlegs.