Hydraena clavigera 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 : 31-32

Hydraena clavigera Zwick, 1977

( Figs. 39, 40 , 43, 44 , 244)

Hydraena clavigera Zwick, 1977: 161 .

Type Material. Holotype (male): Queensland, Young’s Crossing, Petrie [ca. 27° 16' S, 152° 57' E] [labels: Young's X-ing Petrie, Q. 2-X-59 I. C. Yeo // T.7227. // Hydraena clavigera sp. n. det. P. Zwick 1975 Holotypus]. Deposited in the QMBA.

Differential Diagnosis. Similar to H. tricantha in body size and color ( Figs. 38–40 ); differing therefrom by the wider pronotal base, the smaller pronotal macula, the more convex elytra, and the wider, more narrowly separated plaques. The aedeagi of the two species also suggest a rather close relationship ( Figs. 43, 44 , 49, 51 ).

Description. Size: holotype (length/width, mm): body (length to elytral apices) 1.48/0.63; head 0.19/ 0.31; pronotum 0.38/0.49; elytra 0.91/0.63. Head dark brown; pronotum testaceous with brown macula; elytra dark brown with light brown to testaceous humeral angles and elytral apices; legs and palpi testaceous (holotype at light extreme of color variation).

Frons punctures ca. 1xef; interstices shining, 2–3xpd. Clypeus microreticulate laterally, finely sparsely punctate medially. Mentum 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 denser at anterior, ca. 0.5–1x diameter of discal punctures; PF1 and PF4 absent; PF2 very small and shallow; PF3 moderately deep.

Elytral punctures ca.1xpd largest pronotal punctures. Intervals not raised, shining, width about 1xpd, as are interstices between punctures of a row. Apices in dorsal aspect gradually rounded to subtruncate, in posterior aspect margins form moderately strong angle with one another.

Ratios of P2 width and plaque shape (P2/w/l/s) ca. 1/2/2/1. P1 laminate; median carina angulate in profile. P2 narrow, l/w ca. 2/1, sides parallel, apex blunt. Plaques elongate oval, located in posterior 1/2 of metaventrite on sides of deep median triangular depression, plaques not attaining anterior apex of triangle. AIS flat, width at arcuate posterior margin 2–3x P2. Protibia widened to about midlength, then markedly excavate, a prominent spine at base of excavation; meso- and metatibiae slender. Last sternite symmetrical or nearly so; last tergite with small, but rather deep apicomedian concavity.

Aedeagus ( Figs. 43, 44 ) main-piece with distal part greatly extended right side, apically in two parts, one "above" the other; distal piece with long gonopore-bearing flagellum to left of which (ventral view) are three or four process; left paramere moderately wide in lateral aspect, setae at apex and small group of short setae on dorsal margin subapically; right paramere produced on dorsal margin, setae in two groups. Female last tergite with apicomedian incision delimiting two lobes, setae slender, tapering.

Distribution. Currently known from Victoria to southern Queensland, and a disjunct population in northern Queensland (Fig. 244).

Remarks. There is variation in the aedeagal form, most notably the shapes of the processes on the left side, and the shape of the right paramere ( Figs. 43, 44 ). The left paramere has a tiny spine-like process apically (apparently broken off in the holotype), and four long setae near midlength (also present on the holotype, not figured by Zwick (1977)). I have illustrated an aedeagal variant from Mt. Hypipamee National Park; variants intermediate between this form and the holotype have been studied.

Material Examined (165): Australian Capital Territory, 2.5 km S of Tharwa, Naas River, 35° 31' S, 149° 4' E, 31 December 2000, W. D. Shepard (3 MCZ); Paddy's River, nr. Murray's Corner, 35° 25' S, 148° 57' E, 3 April 1965, M. E. Bacchus (MEB 231) (1 BMNH); New South Wales, 34 km SE Braidwood, hwy. 52, Cabbage Tree Creek, wet sclerophyll forest, among algae, stones and leaves along margin of shaded stream, 35° 35' S, 150° 1' E, 2 April 1996, R. E. Roughley (6 NMW); Cabbage Tree Creek, Canberra/ Coast Road, 33° 24' S, 150° 38' E, 5 May 1965, E. Britton (1 ANIC); Cabbage Tree Creek, Clyde Mtn., in wet sand at stream edge, 35° 35' S, 150° 1' E, 28 November 1993, S. A. Slipinski & J. F. Lawrence (1 ANIC); Galston, 33° 39' S, 151° 4' E, 1 February 1929, H. J. Carter (1 ANIC); Mogo Creek, St. Albans, site 2, 33° 12' S, 151° 5' E, 20 November 1996, J. & R. Miller (1 JMC); Nellingen Creek, 5 km W Nellingen, 35° 38' S, 150° 5' E, 19 January 1997, C. Watts (1 SAMA); Numeralla River at Numeralla, waters edge of gravel bar at margin of flowing river, elev. 730 m, 36° 10' S, 149° 20' E, 9 April 2000, N. Porch (NP 26) (3 ANIC); Oberon, 27.5 km NW, in river debris, 33° 31' S, 149° 43' E, 17 November 1991, T. Gush (1 ANIC); The Dorrigo, elev. 914.4 m, 30° 20' S, 152° 24' E, 1–28 February 1932, P. J. Darlington (6 MCZ); Wiangaree SF, Brindle Creek, wet leaves and flood debris, subtrop. forest, elev. 740 m, 28° 22' S, 153° 0' E, 29 February to 3 March 1980, A. Newton & M. Thayer (1 USNM); Williams River, 32° 21' S, 151° 45' E, 1–30 October 1926, H. J. Carter (3 ANIC); Queensland, 15 km S Ravenshoe, nr. Tully Falls, rainforest, 17° 47' S, 145° 34' E, 9 December 1990, D. Larson (1 MCZ); 17 km NE of Mt. Molloy, 16° 40' S, 145° 19' E, 20 December 1986, H. & A. Howden (1 ANIC); 21 km up Mt. Lewis Road, 16° 37' S, 145° 21' E, 1 November 1990, S. DeFaveri & R. Storey (1 QPIM); 30 km NE Brisbane, Mt. Nebo Road, Pond, ca. 200 m, Sclerophyll forest, elev. 540 m, 27° 24' S, 152° 48' E, 21 August 2004, M. A. Jäch (AU 1) (26 NMW); 40 km S Beaudesert, Running Creek, along road between Mt. Chinghee N. P. and Border Ranges N. P., at 7th Bridge, stream, ca. 5–8 m wide, including rockpools, flowing through open forest ( Casuarina , Eucalyptus ), 28° 19' S, 152° 55' E, 25 August 2004, M. A. Jäch (AU 13) (25 NMW); 40 km SSE Brisbane, Mt. Tambourine N. P., Cedar Creek, 27° 55' S, 153° 11' E, 22 August 2004, M. A. Jäch (AU 4) (8 NMW); 40 km up Windsor Tableland road, 16° 13' S, 145° 2' E, 12 November 1990, Storey, DeFaveri & Halfpapp (3 QPIM); 8 km W Rathdowney, Logan River, 28° 12' S, 152° 47' E, 27 August 2004, A. Glaister (4 NMW); 9 km NE Julatten, flight intercept trap, 16° 37' S, 145° 21' E, 26 December 1986 – 8 January 1987, H. & A. Howden (1 CMNO); 90 km SW Brisbane, 40 km NE Warwick, 28° 3' S, 152° 22' E, 26 August 2004, M. A. Jäch (AU 17) (12 NMW); Birthday Ck., 6 km NWbyW of Paluma, leaf and log litter; berlesate ANIC 682, 19° 0' S, 146° 12' E, 25 September 1980, T. Weir (2 ANIC); Canungra Creek, 60 km SSE Brisbane, River (Canungra Creek), ca. 8–10 m wide, through cultivated land, elev. 160 m, 28° 4' S, 153° 6' E, 22 August 2004, M. A. Jäch (AU 6) (1 NMW); Coomera River, 20 km SE Canungra, 28° 8' S, 153° 9' E, 24 August 2004, A. Glaister (5 NMW); Davies Ck. Rd. 20 km SE of Mareeba, ex. rainforest creek, 16° 58' S, 145° 25' E, 26 October 1990, R. I. Storey (1 QPIM); Lamington N. P., Comera River, 80 km S Brisbane, 28° 8' S, 153° 9' E, 24 August 2004, M. A. Jäch (AU 10) (20 NMW); Millaa Millaa [no date], 17° 30' S, 145° 37' E ,, F. H. Taylor (1 ANIC); Mt. Hypipamee N. P., 14 km SW Malanda, rainforest, streamside litter, elev. 960 m, 17° 25' S, 145° 29' E, 24 July 1982, S. & J. Peck (3 ANIC); Mt. Hypipamee N. P., Barron River headwaters, small tributary, ex streambank with gravel and decaying leaves, 17° 25' S, 145° 29' E, 17 January 1998, P. D. Perkins (8 QMBA); Mt. Lewis, flood debris and leaf litter, elev. 960 m, 16° 37' S, 145° 21' E, 19 August 1982, J. & N. Lawrence (5 ANIC); Mulgrave River, Kearney's Falls, 17° 14' S, 145° 47' E, 6 October 1990, D. Larson (1 MCZ); Ravenshoe State Forest, Charmillan Creek, 12 km SE Ravenshoe, ex. bare rocks in splash zone, elev. 900 m, 17° 36' S, 145° 29' E, 15 January 1998, P. D. Perkins (1 MCZ); Young’s Crossing, Petrie, 27° 16' S, 152° 57' E, 2 October 1959, I. C. Yeo (3 UQIC); same locality, 27° 16' S, 152° 57' E, 3 October 1959, I. C. Yeo (1 PZC); Victoria, Lerderderg River, 3.8 km WNW Blackwood; 332, 37° 30' S, 144° 19' E, 8 February 1983, A. J. Boulton (2 ANIC).

Figures

FIGURES 37–40. Hydraena, dorsal and lateral habitus. —37. H. castanea, holotype. —38. H. tricantha, holotype. —39. H. clavigera, holotype. —40. H. clavigera, specimen from Queensland, Mt. Hypipamee National Park.

FIGURES 41–44. Hydraena, aedeagi. —41. H. castanea, holotype (after Zwick 1977). —42. H. castanea, specimen from Victoria, Tarra-Bulga National Park. —43. H. clavigera, holotype (after Zwick 1977). —44. H. clavigera, specimen from Queensland, Mt. Hypipamee National Park.

FIGURES 49–52. Hydraena, aedeagi of holotypes. —49. H. tricantha. —50. H. dorrigoensis. —51. H. tricantha (after Zwick 1977). —52. H. spinissima.