Hydropeza tasmanica, Sinclair, 2016

Sinclair, Bradley J., 2016, Revision of the Australian species of Hydropeza Sinclair (Diptera: Empididae: Ragadinae subfam. nov.), Records of the Australian Museum 68 (1), pp. 1-22 : 17-18

Hydropeza tasmanica sp nov.

Figs 5 , 13–17 , 22, 26-28

Type material. Holotype ♂, labelled: “AUST:TAS: Cradle/ Mtn N.P., Pencil Pine/Tr., 20.ii.1994 / Pencil Pine Ck., 800m / B. J. Sinclair ”; “ HOLOTYPE / Hydropeza / tasmanica/ Sinclair [red label]” (AMS) . Paratypes: Tasmania: 1♀, nr. Collingwood Ck on Lyell Hwy , 27.i.1989, buttongrass/ heath, ypans, D. Bickel (AMS) ; 3♂♂, 5♀♀, Collins Cap, W Mt. Wellington, 800 m, 18.ii.1961, L. Couchman (ANIC) ; 2♂♂, 2♀♀, Cradle Mtn NP, Pencil Pine Tr., 20.ii.1994, Pencil Pine Ck, 800 m, B. J. Sinclair (CNC) ; 1♂, Cradle Mtn NP, Overland / Dove Lake Tr., 21.ii.1994, 800– 1000 m, B. J. Sinclair (CNC) ; 1♂, 3♀♀, Ferntree Gully , ii.1928, I. Smith (ANIC) ; 1♂, 2♀♀, 8 mi E Gormanston , 28.i.1948, Key, Carne & Kerr (ANIC) ; 1♂, 1♀, Hartz Mont. , 10.xii.1922, A. Tonnior (ANIC) ; 1♀, Huon-Picton River junction, 18.ii.1967, A. Neboiss (NMV) ; 1♂, King River , 4.ii.1923, A. Tonnoir (ANIC) ; 1♀, 5 mi. W King William Saddle , 4.xi.1961, N. Dobrotworsky (AMS) ; 7♂♂, 7♀♀, Lyell Hwy Franklin / Gordon Wild Rivers NP, 19.ii.1994, Franklin R., B. J. Sinclair (CNC) ; 3♂♂, 2♀♀, Mt. Barrow St. Res. , 22.ii.1994, B. J. Sinclair (CNC) ; 3♂♂, 2♀♀, Mt. Field , 19.xii.1922, A. Tonnoir (ANIC) ; 1♂, Mt. Field , 11.xi.1953, S. Butler (NMV) ; 5♂♂, 3♀♀, Mt. Field NP, Lake Dobson , small stream inflow, 18.ii.1994, 1020 m, B. J. Sinclair (CNC) ; 1♂, 1♀, Mt. Field NP, Mawson Plateau , 1200 m, alpine sweeping, 25.i.1989, D. Bickel (AMS) ; 2♀♀, Mt. Rufus , 27.i.1948, Key, Carne & Kerr (ANIC) ; 2♂♂, 1♀, Myrtle Forest , 29.i.1937, G.&C. Davis (ANIC) ; 2♂♂, 19♀♀, Pelion Hut, 3 kmS Mt. Oakleigh , 41°50'S 146°03'E, 860 m, vi, x.1990, 8.i.–12.ii., 9.iv.–6.vi.1991, D. Naumann (AMS, ANIC) ; 1♂, 6♀♀, Pelion Hut , 8.i.1991, Nielsen, Edwards (AMS) ; 1♀, Pelion Plain 1 kmS, 7.vi.1990 (AMS) ; 1♂, 4♀♀, Scott Peak, Dam Rd. & Clear Ck, 4–5.ii.1989, wet scler; MT, D. Bickel (AMS) .

Diagnosis. This is the largest Australian species of Hydropeza , distinguished by its dark brown coloration, knob-like ventral process on the male mid femur and slender hind femur.

Description. Head and abdomen dark brown, thorax brown with paler patches; coxae often pale brown, legs progressively darker towards tips. Wing length 6–7.2 mm.

Male. Head ( Fig. 13 ). Ocellar setae very long, erect, divergent, inserted posterior to anterior ocellus; ocellar tubercle with some long setulae; postocellar and postocular setae stout and dark; postgenal setae similar to postoculars. Lower half of face with row of long setulae on inner margin of eye. Scape long and slender, about 2× length of globular pedicel; postpedicel elongate, basal portion onion-shaped, shorter than slender, straight apical portion; arista-like stylus slightly longer than apical portion of postpedicel, concolorous with postpedicel. Proboscis stout and robust, long, extended well beyond mid-length of fore coxa, directed posteriorly; palpus about 0.75× length of proboscis, clothed in long dark setae, some dorsolateral setae stout; apex of palpus pointed; apical third of palpus flattened with dense pubescence.

Thorax. Clothed in fine pruinescence; mesonotum brown, with postpronotal lobe and base of transverse suture pale brown; pleura paler than notum, with dark patches; pale along sutures. Setae generally long and stout; 3–4 acrostichal setulae anterior to 1st dorsocentral seta, about 0.33× length of dc; pprn with 1 seta and several dark, short setulae; 1 long presut spal and 1–2 finer short setae; 5 uniserial dc, about subequal in length, with intermixed finer setae; 3 npl; 1 long psut spal and 1–2 finer setae; 1 pal seta; 1 pair of sctl, with 1–2 pairs of finer outer marginal setae. Antepronotum with pair of long stout setae.

Legs. Brown, increasingly darker apically. Inner anterior margin of fore coxa with more than 20 dark variously lengthened and thickened spine-like setae, mostly concentrated apically and mid-basally; basal most seta longer than width of coxa ( Fig. 14 ). Anterior surface of mid and hind coxae with long brown setae. Legs clothed in very long setae as typical for genus, especially ventral faces. Fore femur slightly arched, with row of 6 anterior setae, apical fifth with 2 longer and stouter anterior setae, longer than width of femur; 4–5 posterodorsal setae and 1 posterior seta at basal third; 1 long preapical posterior seta. Fore tibia with 4 anteroventral, 4 anterodorsal, 4 posteroventral and 4 posterior setae; apical fifth with 1 dorsal and 2 posterodorsal setae; 1 anteroventral and 1 anterodorsal preapical seta. Fore tarsomere 1 with 1 dorsal and 1 anterodorsal near mid-length; 1 ventral seta on basal fourth; apex with 1 anterodorsal and 1 posterodorsal seta. Mid femur with knob-like process at basal third, bearing several short spine-like setae ( Fig. 15 ); 2 long stout setae proximal to process, longer than width of femur ( Fig. 16 ); 3 anterodorsal and 3 posterodorsal setae on distal half; apex with 1 anterodorsal and 1 posterodorsal preapical seta. Mid tibia with anteroventral notch on apical sixth, with distal row of short spine-like setae terminating in pair of claw-like apical setae ( Fig. 16 ); opposite notch with sinuous spur-like anterodorsal seta; 2 anterodorsal setae, 4 posterodorsal setae and 2 anterior setae. Mid tarsomere 1 with ventral curve at base, with long anterior seta; 1 anterodorsal, 1 posterodorsal seta; apex with several preapical stout setae. Hind femur with erect dorsal setae; 1 preapical anterior, 2 preapical anterodorsal and 1 preapical posterodorsal setae on apical fourth, longer than width of femur. Hind tibia with 4–5 anterodorsal and posterodorsal setae; 2 preapical anterior setae; 1 anteroventral seta on apical third. Hind tarsomere 1 with several dorsal and preapical setae. Tarsomeres of fore and midlegs much longer than tibia; ventral apical margin of tarsomere 4 of fore and midlegs somewhat pale, flattened and expanded; tarsomere 4 of hindleg laterally compressed ventrally, keel-like, extending beyond apex; tarsomere 5 of each leg lacking dorsoapical extension ( Fig. 17 ).

Wing ( Fig. 28 ). Infuscate with 1 long basal costal seta, longer than sctl; all veins lacking setulae; R 4 and R 5 distinctly divergent apically, base of R 4 often weakened; bm-m complete; cell dm truncate to slightly produced, longer than length of cell bm; CuA + CuP present only as short streak. Halter brown.

Abdomen. Tergites and sternites clothed in setae; setae of posterior margin overlapping more than half length of following tergite. T8 broad, more than half length of T7; posterior marginal setae greatly reduced in length compared to preceding tergites.

Terminalia ( Figs 26, 27 ). Cercus divided into two components: anterior cercus small, thinly sclerotized sclerite surrounding anus, bearing long setae; posterior cercus sickle-shaped, heavily sclerotized with peg-like setae along posteromedial margin; apex of posterior cercus tapered, bearing stout terminal seta. Epandrium small, bilobed with longer setae of posterior lobe; lamellae separated dorsally beneath cercus by wide membranous gap; epandrium not prolonged posteriorly. Surstylus not differentiated. Hypandrium keel-like, prolonged dorsally into phallic guide; gonocoxal apodeme inconspicuous; long setae on posterior half extending to base of dorsal extension; postgonite finger-like, slightly curved. Phallus long and filamentous, extending anteriorly into abdomen for 2–3 segments, twisted into figure-8, emerging from phallic guide of hypandrium; ejaculatory apodeme reduced not plate-like.

Female. Similar to male except as follows: mid femur and tibia lacking modified setae and processes. Terminalia (not dissected): cercus long and slender with rounded apex.

Distribution. This species is restricted to Tasmania (Fig. 22), occurring in upland streams and rivers from western, northeastern and southern Tasmania.

Etymology. The specific name refers to the distribution of this species, which is widespread in Tasmania.

Remarks. The shape of the hypandrium and epandrium is very similar to H. wardi Sinclair & McLellan from New Zealand.

Figures

Figures 3–6. Habitus images of dried mounted male species of Hydropeza, lateral view. (3) H. aptera. (4) H. intricata. (5) H. tasmanica. (6) H. unguicula. Scale bars = 1.0 mm, except Fig. 3 where scale bar = 0.5 mm.

Figures 13–18. Scanning electron photographs of Hydropeza tasmanica and digital image of foreleg of H. unguicula. (13) Head (scale bar = 0.5 mm) (from Sinclair & McLellan, 2004, fig. 10). (14) Fore coxae (scale bar = 0.2 mm). (15) Male mid femur (scale bar = 0.1 mm). (16) Male mid femur and tibia (scale bar = 0.5 mm). (17) Tarsomere 5 and acropod (scale bar = 0.2 mm). (18) Male forelegs of H. unguicula (scale bar = 1.0 mm).

Figures 26–28. Hydropeza tasmanica. (26) Male epandrium, lateral view. (27) Male terminalia with epandrium removed, lateral view. (28) Wing.Abbreviations:bm-m, basal medial crossvein;cerc, cercus;cua, anterior cubital cell;CuA+CuP, anterior branch of cubital vein plus posterior branch of cubital vein; dm, discal medial cell; hypd, hypandrium; M, medial vein; p cerc, posterior cercus; pgt, postgonite; ph, phallus; R, radial vein. Scale bars = 0.4 mm, except Fig. 28 where scale bar = 0.1 mm.