Gymnochthebius clarki (Deane) Perkins, 2005

Perkins, Philip D., 2005, A revision of the water beetle genus Gymnochthebius Orchymont (Coleoptera: Hydraenidae) for Australia and Papua New Guinea, Zootaxa 1024 (1), pp. 1-161 : 1-161

Gymnochthebius clarki (Deane) new combination

( Figures 13 , 14 , 77)

Ochthebius clarki Deane 1931: 167 .

Ochthebius angustipennis Deane 1931: 167 (holotype male deposited in MVMA, examined; type locality New South Wales: Sydney). New synonymy.

Type Material. Holotype of Ochthebius clarki (female): Australia: New South Wales: Sydney; [labels: "Sydney H. W. Cox"; "3659 3660 Type"; " Ochthebius clarki Deane. "]. Deposited in the MVMA. Holotype of Ochthebius angustipennis (male): Australia: New South Wales: Sydney. Deposited in the MVMA.

Differential Diagnosis. Recognized by the dark brown to black head and pronotum with faint metallic reflections, the gradually sloping pronotal foveae which are moderately coarsely punctate like reliefs, the elytral series and intervals of about equal width, and the abdominal hydrofuge pubescence present on ventrites 1–2 entirely and 3–4 partially, with the hair­line medially on the anterior part of the 3rd, weakly sinuate from there to anterolateral extreme of the 4th. Readily distinguished from G. hesperius (which see) by color, body form, and male genitalia ( Figs. 14 , 20).

Description. Size (length/width, mm) of the holotype of G. clarki : body (length to elytral apices) 1.57/0.74; head 0.28/0.42; pronotum 0.40/0.52; elytra 1.06/0.74. Dorsum shining, head and pronotum dark brown to black with faint metallic reflections, elytra dark brown, legs brown.

Frons very finely sparsely punctate, very sparsely pubescent; interocular foveae shallow; interocular tuberculi distinct; basomedial fovea narrowly confluent with interocular foveae. Frontoclypeal suture deeply impressed, arcuate to weakly bisinuate. Clypeus midlength:apical width 1:2, very finely sparsely punctate; pubescence very sparse on weakly raised disc, slightly denser laterally; anterior margin straight in dorsal aspect, evenly arcuate in frontal aspect. Labrum length:width 1:2.

Pronotum lateral hyaline border well developed, origin at base of lateral depression, markedly arcuate to posterior angles, very narrow around posterior margin; anterior margin of pronotum straight or weakly arcuate in midregion; each lateral depression with posterior in form of obtuse, almost right angle, lateral margin weakly arcuate anteriorly, weakly emarginate before posterior angle, with fringe of short setae; lateral fossulae moderately deep, effacedly if at all microreticulate; pronotal disc weakly convex, reliefs highly shining, sparsely, moderately coarsely punctate, punctures intermediate in size between those of head and elytra; each puncture on reliefs with an extremely small decumbent seta; median groove narrow, moderately shallow, slightly widened just before ends, then tapering, nearly attaining margins in most specimens; anterior and posterior foveae moderately deep, punctate like reliefs, margins gradually sloping, very ill­defined; posterolateral angles each with indistinct shallow impression.

Elytra weakly convex on disc, with six rows of closely spaced, small punctures between suture and humeri; intervals weakly rounded, as wide as punctures; posterior declivity very gradual, summit slightly past midlength; striae 2 and 3 terminating into 4 at about apical 1/4; elytral margin lacking prominent setae; explanate margin narrow, slightly wider in female than male, terminating near posterior 3/4.

Metasternal glabrous area length about equal width, widest before midlength, rhomboidal, shining, with a few setiferous punctures on disc. Abdominal ventrites 1–2 entirely and 3–4 partially hydrofuge pubescent; hairline medially on anterior part of 3rd, weakly sinuate from there to anterolateral extreme of 4th; cuticle strongly shining posterior to hairline.

Aedeagus ( Fig. 14 ): Length of main­piece 0.25 mm, length to tip of parameres 0.26 mm; lobes relatively short, not barbed; notches U­shaped, ventral notch widest apically, dorsal notch deeper and slightly wider ventral notch; duct weakly arcuate, width subequal that of lobe, tip truncate, simple; apical paramere seta elongate, ca. 2–3x length of next longest seta.

Distribution. A widely distributed species, known from Australia and Papua New Guinea. In Australia found from Victoria northward to northern Queensland and then west to northern Northern Territory (Fig. 77).

Material Examined (298): Australia: New South Wales: Beaury Creek, adjacent Woodenbong State Forest, ca. 8 km [beeline] SW Woodenbong, ca. 120 km [beeline] SW Brisbane , 28° 24’09.9”S 152° 32’ 18.0”E, Residual pools and small rock pools in river bed ( Beaury Creek ), in cultivated cattle country, 25 August 2004, M. A. Jäch (AU 14) (2 NMW) ; Nyngan , 31° 33' S, 147° 12' E, 16 March 1963, C. Watts (4 SAMA) ; Parramatta , 33° 48' S, 151° 0' E, 26 March 1965, M. E. Bacchus (MEB 216) (2 BMNH) ; Shaw Creek, c. 8 m., Springwood­Richmond Rd. , 33° 38' S, 150° 38' E, 24 March 1965, M. E. Bacchus (MEB 214) (1 BMNH) ; Northern Territory: 10 mi. E of Daly River , at light, 13° 45' S, 130° 51' E, 28 June 1972, B. K. Head (7 SAMA) ; 16 km E by N of Mt Cahill , 12° 51' S, 132° 42' E, 13 June 1973, Upton & Feehan (8 ANIC) ; 22 km WSW of Borroloola , 16° 8' S, 136° 6' E, 2 November 1975, M. S. Upton (10 ANIC) ; 7 km NW by N of Cahills Crossing, East Alligator River , 12° 23' S, 132° 56' E, 27 May 1973, E. G. Matthews (13 ANIC) ; 9 km N by E of Mudginbarry , 12° 31' S, 132° 54' E, 26 May 1973, E. G. Matthews (7 ANIC) ; same locality, 12° 31' S, 132° 54' E, 10 June 1973, Upton & Feehan (1 ANIC) ; Adelaide River, at Daly River road crossing, 13° 29' S, 131° 6' E, 9 November 1972, E. B. Britton (9 ANIC) ; Canon Hill Kakadu , 12° 16' S, 132° 40' E, 10 October 1998, C. Watts (1 SAMA) ; Daly R. Mission , 13° 18' S, 130° 15' E, 17 August 1974, J. Hutchinson (11 ANIC) ; Humpty Doo (6 km E), at UV light, 12° 37' S, 131° 15' E, 6–19 October 1990, R. I. Storey (5 QPIM) ; Ja Ja Billabong, 6 km NbyE Mudginberri, Berlesate , open forest litter, 12° 33', 132° 52' E, 27 November 1992, M. Storrs (22 ANIC) ; Jim Jim Creek , 19 km WSW of Mt. Cahill, 12° 57' S, 132° 33' E, 24 October 1972, E. B. Britton (26 ANIC) ; same locality, 12° 58' S, 132° 35' E, 17 July 1973, Upton & Feehan (1 ANIC) ; Koongarra , 15 km E of Mt Cahill, 12° 52' S, 132° 50' E, 12 June 1973, Upton & Feehan (9 ANIC) ; Nourlangie Creek , 8 km. E of Mt. Cahill, at light, 12° 52' S, 132° 47' E, 27 October 1972, E. B. Britton (1 ANIC) ; Nourlangie Creek , 8 km. N of Mt. Cahill, at light, 12° 48' S, 132° 42' E, 26 October 1972, E. B. Britton (1 ANIC) ; Red Lily Lagoon nr. Daly River , lagoon, 13° 45' S, 130° 42' E, 9 August 1980, M. B. Malipatil (12 MAGD) ; Yellow Water swamp nr Cooinda , swamp, 12° 16' S, 132° 40' E, 18 November 1979, M. B. Malipatil (5 MAGD) ; Queensland: 11 km WSW of Petford , at light, 17° 26' S, 144° 54' E, 3–4 April 1988, R. I. Storey (5 QPIM) ; 31 km NW by N of Longreach , 23° 13' S, 144° 4' E, 10 May 1973, M. S. Upton (2 ANIC) ; Biloela , 24° 24' S, 150° 30' E, 7 September 1972, H. E. Hinton (6 BMNH) ; Boggomoss No. 21, via Taroom , aquatic collection, 073, 25° 27' S, 150° 3' E, 11 November 1996, Thompson & Monteith (3 ANIC) ; Brisbane , 27° 22' S, 152° 46' E, 27 June 1927, not given (4 UQIC) ; Brookfield , 27° 29' S, 152° 53' E, 22 January 1982, J. Sedlacek (1 NMW) ; Bruce Hwy. nr Childers , 10 km N Howard, creeks, 25° 14' S, 152° 16' E, 17 November 1996, L. Hendrich (15 NMW) ; Bushland Beach , 12 km N Townsville, 19° 12' S, 146° 41' E, 15–20 March 1998, A. J. Watts (3 SAMA) ; Cape River , 100 km S Charters Towers, 21° 0' S, 146° 25' E, 12 December 2002, C. H. S. Watts (13 SAMA) ; Cape York, Archer River, Archer Bend , moderately large shallow billabong/pool in otherwise dry river bed; unvegetated with thick layer of dead leaves etc., 13° 28' S, 142° 12' E, 28 September 1983, C. Watts (1 BMNH) ; Carnarvon Ck. 17 km E Park Office, 25° 1' S, 148° 18' E, 14 August 2004, A. Glaister (4 NMW) ; Connor’s River , 91.5 mi. S Mackay, 22° 39' S, 149° 4' E, 3 September 1972, H. E. Hinton (2 BMNH) ; Gladstone [no date], 23° 52' S, 151° 16' E, Lea (6 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) ; Laura , moderate sized, shallow stoney river with little vegetation, 15° 34' S, 144° 27' E, 18 July 1982, C. Watts (2 SAMA) ; Leichart Creek , 8k N Bluewater, 19° 10' S, 146° 32' E, 18 December 2002, A. J. & C. H. S. Watts (1 SAMA) ; Moggill , 27° 32' S, 152° 56' E, 4 March 1933, H. Hacker (1 ANIC) ; Moran's Creek, 760–820 m a.s.l., SW of O'Reilly's Rainforest Guesthouse, Lamington NP, ca. 80 km S Brisbane [beeline], 28° 14’11.2”S 153° 08’ 01.1”E – 28° 13’59”S 153° 07’ 27”E, River ( Moran's Creek ), ca. 2–4 m wide, through dense rain forest, Eucalypt forest and open grassland, 760–820 m a.s.l., 24 August 2004, M. A. Jäch (AU 9) (2 NMW) ; N. Pine R., Brisbane , 27° 17' S, 153° 4' E, 5 March 1932, P. J. Darlington (2 MCZ) ; North Maclean , on river bank, 27° 47' S, 153° 1' E, 13 October 1991, T. Gush (1 ANIC) ; South of Charleville , 26° 24' S, 146° 20' E, 9 May 1973, M. S. Upton (4 ANIC) ; Station Brdg 6 km SW Eidsvold, 25° 22' S, 151° 4' E, 15 August 2004, A. Glaister (3 NMW) ; Taroom Dist. Boggom. 1, 157, 25° 26' S, 150° 2' E, 8 June 1996, R. Kristensen (1 ANIC) ; Taroom Dist. Boggom.11, 162, 25° 28' S, 150° 3' E, 14 June 1996, R. Kristensen (12 ANIC) ; Taroom Dist. Boggom.2, 159, 25° 26' S, 150° 1' E, 8 June 1996, R. Kristensen (4 ANIC) ; Taroom Dist. Boggom.5, 160, 25° 26' S, 150° 1' E, 14 June 1996, R. Kristensen (2 ANIC) ; Towns­ ville, 19° 15' S, 146° 48' E, 24 March 1932, P. J. Darlington (7 MCZ) ; same locality, elev. 10 m, 19° 15' S, 146° 48' E, 17 January 1993, Wewalka (1 NMW) ; Townsville [no date], 19° 15' S, 146° 48' E, G. F. Hill (1 MVMA) ; Victoria: Tarago R. at Elston Rd., 1.75 km W Neerim, ex silty sand patches between waterside vegetation and wet litter along edge of riffle. Dry sclerophyll forest­pasture, elev. 170 m, 38° 28' S, 145° 56' E, 15 January 1999, N. Porch (NP 20) (2 ANIC) ; Papua New Guinea: Central District, Loloki , 10 miles N of Port Moresby, ex. gravel in roadside drain, 19 March 1965, M. E. Bacchus (MEB 209) (2 BMNH) ; Moitaka , 7 miles N of Port Moresby, ex. dead leaves in gravelly shallow of small pond, 17 March 1965, M. E. Bacchus (MEB 207) (5 BMNH) ; Moitaka , 7 miles N of Port Moresby, very muddy gravel bank of field drain, 17 March 1965, M. E. Bacchus (MEB 204) (9 BMNH) ; Port Moresby ­ Brown River Road, ex. grassy shallows of large muddy pond, 15 March 1965, M. E. Bacchus (MEB 195) (9 BMNH) . Representative specimens to be deposited in AMSA, CMNH, FMNH, MCZ, MVMA, NPC, QMBA, USNM, and WAMP .

Figures

FIGURE 13. Gymnochthebius clarki, holotype female. Dorsal and lateral habitus.

FIGURE 14. Gymnochthebius clarki. Aedeagus (drawn from holotype of G. angustipennis (Deane), junior synonym).