Hydraena australica Zwick, 1977

PERKINS, PHILIP D., 2007, A revision of the Australian species of the water beetle genus Hydraena Kugelann (Coleoptera: Hydraenidae), Zootaxa 1489 (1), pp. 1-207 : 73

Hydraena australica Zwick, 1977

(Figs. 115, 119, 120, 217, 239)

Hydraena australica Zwick, 1977: 173 .

Type Material. Holotype (male): Northern Territory, Howard Springs , 24 km S of Darwin [ca. 12° 28' S, 131° 3' E] [labels: 12.28S 131.03E Howard Springs, N. T. 24 km S of Darwin 10.xi.72, rainforest, at light, E. Britton // [pink label] // HOLOTYPE // Aedeagus drawn by P. D. Perkins // DIGITAL IMAGE captured 2004 P. D. Perkins // Hydraena australica Zwick Holo-Typus des. P. Zwick 1977]. Deposited in the ANIC.

Differential Diagnosis. Similar in dorsal habitus to H. parciplumea ; differing therefrom by the larger size (ca. 1.45 vs. 1.31 mm), the less distinctively maculate pronotum, the slightly less distinctive dorsal setae, and the wider, non-carinate plaques (Figs. 115, 117). The aedeagi of the two species distinctively differ (Figs. 114, 119, 120).

Description. Size: holotype (length/width, mm): body (length to elytral apices) 1.45/0.62; head 0.25/ 0.35; pronotum 0.36/0.47, PA 0.39, PB 0.47; elytra 0.86/0.62. Dorsum brown, except head and disc of pronotum piceous, legs and palpi testaceous, distal 1/2 of last palpomere darker.

Frons punctures ca. 1xef; interstices shining, 1–2xpd. Clypeus microreticulate laterally, finely sparsely punctate medially. Mentum weakly shining, very finely sparsely punctate; postmentum microreticulate. Genae raised, lacking posterior ridge. Pronotal punctures on disc slightly larger than those of frons, interstices shining, 1–2xpd, punctures sparser on disc than anteriorly and posteriorly; PF1 and PF4 absent; PF2 very shallow; PF3 shallow, broad.

Elytral punctures on disc about 1xpd of largest pronotal punctures, becoming smaller and shallower posteriorly. Intervals not raised, shining, width about 1–2xpd, as are interstices between punctures of a row. Apices in dorsal aspect gradually, conjointly rounded, in posterior aspect margins form shallow angle with one another.

Ratios of P2 width and plaque shape (P2/w/l/s) ca. 2/1/3/2. P1 laminate; median carina angulate in profile. P2 l/w ca. 5/4, sides parallel, apex blunt. Plaques narrow, located in posterior 7/10 of metaventrite on sides of moderately deep median elongate subtriangular depression, plaques slightly more narrowly separated anteriorly than posteriorly. AIS flat, width at arcuate posterior margin 1.5x P2. Legs simple. Last sternite symmetrical or nearly so; last tergite notched apicomedially.

Aedeagus (Figs. 119, 120) main-piece with narrow, bisinuate, pointed process on right side; distal piece simple in ventral view, multi-lobed in lateral view, gonopore-bearing flagellum terminal, short; parameres inserting at about same level on main-piece; left paramere very slender, longer than right; right paramere with about four long setae on ventral margin near midlength. Female last tergite with three incisions, delimiting four lobes, setae slender, tapering; gonocoxite as illustrated (Fig. 217).

Distribution. Widely distributed across northern Australia (Fig. 239).

Material Examined (278): Northern Territory, 30 km WSW of Mt. Cahill , 12° 51' S, 132° 42' E, 19 May 1973, E. G. Matthews (1 ANIC) ; Caranbirini Waterhole, 3 km SW of Borroloola, at light, 16° 16' S, 136° 5' E, 14 April 1976, J. E. Feehan (3 ANIC, 9 MAGD); Cooper Creek , 19 km E. by S of Mt. Borradaile , in sand at edge of stagnant pool, 12° 6' S, 133° 4' E, 31 May 1973, E. G. Mathews (1 ANIC) ; Darwin , 12° 27' S, 130° 50' E, 13 May 1963, C. Watts (11 SAMA) ; Kakadu N. P., Gungurul Lookout , creek, elev. 50 m, 13° 59' S, 132° 19' E, 1 November 1996, L. Hendrich (76 NMW) ; Kakadu N. P., Upper South Alligator , light trap, 12° 16' S, 132° 40' E, 5 May 1988, P. S. Cranston (1 ANIC) ; Keep River Gorge, Keep River Nat. Pk., deep billabong with rocks and floating leaves, etc., 15° 50' S, 129° 7' E, 22 July 1994, T. Weir & A. Roach (1 ANIC) ; Koongarra , 15 km E of Mt. Cahill , 12° 52' S, 132° 50' E, 24 May 1973, E. G. Matthews (1 ANIC) ; McArthur River , 14 km S by W of Cape Crawford , 16° 47' S, 135° 45' E, 25 October 1975, M. S. Upton (3 ANIC) ; McArthur River , 14 km SW of Cape Crawford , 16° 47' S, 135° 45' E, 11 April 1975, J. E. Feehan (1 ANIC) ; McArthur River , 48 km SW by S of Borroloola , at light, 15° 48' S, 136° 40' E, 13 May 1973, J. E. Feehan (2 ANIC) ; McArthur River , 80 km SW of Borroloola , 16° 39' S, 135° 51' E, 13 May 1973, M. S. Upton (1 ANIC) ; Pine Creek , 13° 49' S, 131° 45' E, 5 May 1963, C. Watts (3 SAMA) ; South Alligator River crossing Old Jim Jim rd. , 13° 0' S, 132° 20' E, 10 October 1998, C. Watts (26 SAMA) ; Surprise Creek , 45 km SW by S of Borroloola , at light, 16° 25' S, 136° 5' E, 14 April 1976, J. E. Feehan (2 ANIC) ; Queensland, 1 km W of Annan Falls , 15° 31' S, 145° 14' E, 26 May 1976, E. B. Britton (1 ANIC) ; 11 km WSW of Petford , at light, 17° 26' S, 144° 54' E, 3–4 April 1988, R. I. Storey (2 QPIM) ; 16 km SSE of Musselbrook Mining Camp , at light, 18° 44' S, 138° 12' E, 18 May 1995, T. Weir (1 ANIC) ; 19 km NE Mareeba, MDPI intercept trap site No. 26, flight intercept trap, 16° 54' S, 145° 34' E, 20 December 1984 – 7 January 1985, Storey & Titmarsh (1 QPIM) ; 24 mi. SE Einasleigh , elev. 500 m, 18° 32' S, 143° 51' E, 4 November 1962, E. S. Ross & D. Q. Cavagnaro (2 CAS) ; 3 km W of Batavia Downs , flight intercept trap, 12° 40' S, 142° 39' E, 22 June–23 August 1992, P. Zborowski & J. Cardale (1 ANIC) ; 40 Mile Scrub N. P. via Mt. Garnet, MDPI intercept trap site No. 13, flight intercept trap, 17° 40' S, 145° 7' E, 28 November–21 December 1985, Storey & Heiner (1 QPIM) ; 40 Mile Scrub N. P. via Mt. Garnet, MDPI intercept trap site No. 13, flight intercept trap, 17° 40' S, 145° 7' E, 21 December 1985 – 10 January 1986, Storey & Heiner (2 QPIM) ; 5.6 km NE Kuranda, Black Mountain Rd. , at light, 16° 49' S, 145° 38' E, 6 February 1989, H. & A. Howden (6 CMNO) ; 5.6 km NE Kuranda, Black Mountain Rd. , ex fungi, 16° 49' S, 145° 38' E, 6 February 1989, A. Howden (1 CMNO) ; 6 km W Dimbulah , 17° 8' S, 145° 6' E, 10 November 1990, D. Larson (1 MCZ) ; 7 km S of Batavia Downs , flight intercept trap, 12° 43' S, 142° 42' E, 19 June–22 July 1992, P. Zborowski & E. S. Nielsen (1 ANIC) ; Batavia Downs Hs. , sweeping water, still pool, 12° 40' S, 142° 40' E, 11 December 1992, W. Dressler & P. Zborowski (6 ANIC) ; Boggy Ck., 75 km Cooktown, Cooktown Rd. , 16° 37' S, 145° 21' E, 26 April 1976, E. B. Britton (2 ANIC) ; Coen, C. York , 13° 48' S, 143° 12' E, 1–30 May 1932, P. J. Darlington (4 MCZ) ; Cooktown, Airport Rd. , roadside swamp, 15° 28' S, 145° 11' E, 24 May 1976, E. B. Britton (9 ANIC) ; Emu Creek , 1 km E Petford , 17° 19' S, 144° 58' E, 28 March 1996, C. Watts (19 SAMA) ; Granite Gorge, 9.5 km SW of Mareeba, MDPI intercept trap site No. 30, flight intercept trap, 17° 2' S, 145° 20' E, 17 February–22 March 1988, Storey & De Faveri (1 QPIM) ; Greenvale 70 km SW, at light, 19° 23' S, 144° 37' E, 1–10 March 1996, A. J. Watts (1 SAMA) ; Hann R., 73 km NW by W of Laura , 14° 44' S, 144° 4' E, 27 June 1986, T. Weir & A. Calder (3 ANIC) ; Hann River , water sweep, 15° 11' S, 143° 52' E, 16 August 1992, P. Zborowski & J. Cardale (2 ANIC) ; Holts Creek , 8 km N of Musselbrook Mining Camp , 18° 33' S, 138° 11' E, 10–20 May 1995, T. Weir (1 ANIC) ; Kelly St., George R. Cooktown Rd. , 16° 29' S, 144° 47' E, 22 May 1976, E. B. Britton (2 ANIC) ; Kennedy River , water sweep, 15° 26' S, 144° 10' E, 24 April 1994, P. Zborowski (10 ANIC) ; Laura River , pools in stony river bed, full sun, algal growth, 15° 21' S, 144° 27' E, 27 May 1994, P. Zborowski (1 ANIC) ; McIlwraith Range, Weather Stn. , 13° 39' S, 143° 25' E, 23 July 1982, C. Watts (4 SAMA) ; Moonlight Creek , water sweep, 12° 42' S, 142° 30' E, 22 June 1993, P. Zborowski & I. Naumann (1 ANIC) ; Murrays Spring , 8 km W by N of Musselbrook Mining Camp , large pool in rocky creek bed, sandy bottom water lillies, Pandanus , algal growth, 18° 35' S, 138° 3' E, 9–20 May 1995, T. Weir (2 ANIC) ; Normanton , at light, 17° 40' S, 141° 4' E, 4 May 1963, P. Aitken & N. B. Tindale (2 SAMA) ; Reedy St., George R. Cooktown Rd. , 16° 28' S, 144° 46' E, 22 May 1976, E. B. Britton (6 ANIC) ; Split Rock , flight intercept trap, 15° 39' S, 144° 31' E, 24 August–21 September 1992, P. Zborowski & L. Miller (1 ANIC) ; Western Australia, 14 km SbyE Kalumburu Mission, CALM Site 4/3 [Western Australian Department of Conservation and Land Management], at light, open forest, 14° 25' S, 126° 40' E, 3–6 June 1988, T. A. Weir (13 ANIC) ; 4 km SbyW Mining Camp, Mitchell Plateau , 14° 52' S, 125° 50' E, 13 May 1983, DCF Rentz, J. Balderson (17) (5 ANIC) ; Derby , N. W. A. [no date], 17° 18' S, 123° 37' E ,, [collector not given] (7 SAMA) ; East Kimberley, Meelarie Creek , 5 km N Drysdale Crossing , elev. 350 m, 15° 40' S, 126° 24' E, 19 June 1999, L. Hendrich (7 NMW) ; East Kimberley , N. N. Creek , 40 km W Kununurra , elev. 50 m, 15° 46' S, 128° 44' E, 29 June 1999, L. Hendrich (2 NMW) ; Synnot Ck., CALM Site 25/1 [Western Australian Department of Conservation and Land Management], at light, closed forest margin, 16° 31' S, 125° 16' E, 17– 20 June 1988, T. A. Weir (1 ANIC) ; Synnot Ck., CALM Site 25/1 [Western Australian Department of Conservation and Land Management], at light, open forest, 16° 31' S, 125° 16' E, 17–20 June 1988, T. A. Weir (1 ANIC) .