Hydraena ambiflagellata Zwick, 1977: 169 A revision of the Australian species of the water beetle genus Hydraena Kugelann (Coleoptera: Hydraenidae) PERKINS, PHILIP D. Zootaxa 2007 2007-05-31 1489 1 1 207 6MHFB Zwick, 1977 Zwick Holo-Typus 1977 [151,611,1186,1212] Insecta Hydraenidae Hydraena Animalia Coleoptera 88 89 Arthropoda species ambiflagellata      Hydraena ambiflagellata Zwick, 1977: 169.   Type Material.  Holotype(male):  Victoria, stagnant branch of Woori Yallock Creekon road to Warburton[labels: Australia, Vic., Wng Melbourne, Woori Yallock Cr.  4.xi.1972 Zwick// Hydraena ambiflagellata Zwick Holo-Typusdes. P. Zwick, 1977// DIGITAL IMAGEcaptured 2004 P. D. Perkins]. Depositedin the MVMA.   Differential Diagnosis.Externally very similar to other members of the  ambiflagellataGroup (Figs. 147–150); reliable determinations will require examination of the male genitalia (Figs. 155, 156). Males, and some females, have a small tubercle on the lateral margin of each plaque; these are not present in the other members of the  ambiflagellatagroup.   Description. Size: holotype(length/width, mm): body (length to elytral apices) 1.38/0.58; head 0.17/ 0.32; pronotum 0.34/0.46, PA 0.37, PB 0.44; elytra 0.88/0.58. Dorsum dark brown, anterior and posterior margins of pronotum light brown to testaceous, legs testaceous, maxillary palpi brown except testaceous tip. Dorsal punctures each with a fine recumbent seta. Frons punctures ca. 1–2xef; interstices shining, 0.5–3xpd. Clypeus microreticulate laterally, finely sparsely punctate medially. Mentum shining, very finely sparsely punctate; postmentum microreticulate. Genae raised, lacking posterior ridge. Pronotal punctures on disc ca. 1xpd those of frons, interstices shining, 2–6xpd, punctures denser at anterior; PF1 and PF4 absent; PF2 very shallow, nearly absent; PF3 shallow, broad. Elytral punctures about equal size of largest pronotal punctures. Intervals not raised, shining, width ca. 2– 3xpd, as are interstices between punctures of a row. Apices in dorsal aspect gradually rounded, in posterior aspect margins form shallow angle with one another. Ratios of P2 width and plaque shape (P2/w/l/s) ca. 3/3/8/3. P1 laminate; median carina posterior extreme slightly more elevated than remainder. P2 narrow, l/w ca. 2/1, sides nearly parallel, apex widened toward blunt apex. Plaques very weakly arcuate, well delimited, slightly raised, convergent but only slightly tapering anteriorly; lateral margin with minute subtubercle near midlength; located in posterior 7/10 of metaventrite on sides of deep median triangular depression. No midlongitudinal carina between mesoventral intercoxal process and plaques. Cuticle asperite under hydrofuge pubescence. AIS flat, width at arcuate posterior margin 2–3x P2. Protibia (male) weakly widened on inner surface subapically; metatibia slender, gradually and very slightly increasing in width over length; distal 1/2 on inner surface with fringe of setae that at its widest is ca. width of tibia (visible in fluid; setae lie almost flat on cuticle in dry specimens). Last sternite very slightly asymmetrical; last tergite with very small, slightly off-center concavity. Aedeagus (Figs. 155, 156) main-piece wide in both views, process on right side terminating in flagellum; distal piece much larger than process of main-piece, irregularly shaped, thickened on dorsal surface, with long gonopore bearing flagellum; left paramere very broad, shorter than right, setae long, in row across arcuate distal margin; right paramere inserting slightly more distally than left paramere, sinuate, widened in distal 1/2, setae long, in two groups, one group on each side of main-piece process. Female last tergite with three incisions, delimiting four lobes, setae slender, tapering.   Distribution.In Australiacurrently known from South Australia, Victoria, and Tasmania(Fig. 240). Also known from New Zealand; most likely introduced by human agency ( Delgado and Palma 1997).   Material Examined (77):   Australian Capital Territory, Tidbinbilla Nature Reserve, trickle at campground, 35° 28' S, 148° 54' E,  6 October 2002, P. Zwick(9 PZC);   South Australia,  10 kmN Forreston, 34° 44' S, 138° 57' E,  13 October 2002, C. H. S. Watts(17 SAMA);   13 kmW Meadows, 35° 11' S, 138° 37' E,  26 September 1996, C. Watts(1 SAMA);  Adelaide, Belair N. P., Paroomba Creek, elev.  300 m, 34° 59' S, 138° 38' E,  3 December 1999, L. Hendrich(3 NMW);  Mt. Gambier, 37° 50' S, 140° 45' E,  1–30 December 1961, C. Watts(1 SAMA);  Mt. Lofty Range, 34° 58' S, 138° 42' E,  1–30 November 1931, P. J. Darlington(8 MCZ); S Mt. Lofty Ranges,  30 kmSE Adelaide, Scott Creek Conservation Park, 35° 5' S, 138° 41' E,  18 December 1999, Hands& Hendrich(1 NMW);   Tasmania, Fossey Riveron road to Rosebery, 41° 27' S, 145° 38' E,  2 December 1972, P. Zwick(1 PZC);  Hobart, 42° 52' S, 147° 19' E,  17 April 1917, C. E. Cole(1 SAMA); same locality, 42° 52' S, 147° 19' E,  1–30 August 1961, C. Watts(2 SAMA);  Mount, creek Barrow, inundation debris, 41° 22' S, 147° 21' E,  8 December 1982, Endrödy-Younga(AU 101) (3 TMSA);  St. Patric River, Targa, inundation debris, 41° 18' S, 147° 21' E,  8 December 1982, Endrödy-Younga(AU 104) (5 TMSA);  Tasman Hwy.,  6 kmS Llandaff, elev.  50 m, 41° 56' S, 148° 12' E,  3 February 1998, L. Hendrich(1 NMW);   Victoria, Bright[no date], 36° 46' S, 146° 59' E,, H. W. Darvey(3 MVMA);  Kangaroo Creek on Springhill Rd.,  5.8 kmE Glenlyon, amongst weeds in shallow water at edge of creek (perennial) pools, dry sclerophyll forest, elev.  510 m, 37° 18' S, 144° 18' E,  31 January 1999, N. Porch(NP 24a) (1 ANIC);  Lerderderg River,  4.8 kmWNW Blackwood; 332, 37° 30' S, 144° 19' E,  30 April 1983, A. J. Boulton(1 ANIC);  Stagnantbranch of Woori Yallock Creekon road from Melbourneto Warburton, 37° 44' S, 145° 29' E,  11 October 1972, P. Zwick(1 NMW, 8 PZC); same locality, 37° 44' S, 145° 29' E,  4 November 1972, P. Zwick(6 PZC);  Warburton, 37° 42' S, 145° 44' E,  13 March 1921, C. Oke(4 MVMA). 1972-11-04 DIGITAL, IMAGE, MVMA Woori Yallock Cr. & Zwick & P. D. Perkins & Deposited Australia Woori Yallock Creek Warburton 88 89 1 Victoria holotype 2002-10-06 PZC P. Zwick -35.466667 Tidbinbilla Nature Reserve 1193 148.9 89 90 1 Australian Capital Territory 2002-10-13 SAMA C. H. S. Watts -34.733334 10 km N Forreston 1197 138.95 89 90 1 South Australia 1996-09-26 SAMA Watts -35.183334 13 km W Meadows 1195 138.61667 89 90 1 South Australia 1999-12-03 NMW Belair N. P. & Paroomba Creek & L. Hendrich 300 -34.983334 Adelaide 1196 138.63333 89 90 1 South Australia 1961-12-01 1961-12-30 1961-12-01 SAMA C. Watts -37.833332 Mt. Gambier 1179 140.75 89 90 1 South Australia [367,1407,1192,1218] 1931-11-01 1931-11-30 1931-11-01 MCZ P. J. Darlington -34.966667 Mt. Lofty Range 1196 138.7 89 90 1 South Australia 1999-12-18 NMW Hands & Hendrich -35.083332 Scott Creek Conservation Park 1195 138.68333 Mt. Lofty Ranges 89 90 1 South Australia 1972-12-02 PZC P. Zwick -41.45 Rosebery 1156 145.63333 Fossey River 89 90 1 Tasmania [572,1363,1312,1338] 1917-04-17 SAMA C. E. Cole -42.866665 Hobart 1147 147.31667 89 90 1 Tasmania 1961-08-01 1961-08-30 1961-08-01 SAMA C. Watts -42.866665 Hobart 1147 147.31667 89 90 1 Tasmania 1982-12-08 TMSA Endrody-Younga -41.366665 Barrow 1156 147.35 Mount 89 90 1 Tasmania 1982-12-08 TMSA Endrody-Younga -41.3 Targa 1157 147.35 St. Patric River 89 90 1 Tasmania 1998-02-03 NMW L. Hendrich 50 -41.933334 Tasman Hwy. 1153 148.2 89 90 1 Tasmania MVMA H. W. Darvey -36.766666 Bright 1185 146.98334 89 90 1 Victoria 1999-01-31 ANIC N. Porch 510 -37.3 Kangaroo Creek on Springhill Rd. 1182 144.3 89 90 1 Victoria 1983-04-30 ANIC A. J. Boulton -37.5 Lerderderg River 1181 144.31667 89 90 1 Victoria 1972-10-11 1972-11-04 1972-10-11 NMW, PZC P. Zwick Stagnant -37.733334 Melbourne 1180 145.48334 Woori Yallock Creek 89 90 1 Victoria 1921-03-13 MVMA C. Oke -37.7 Warburton 1180 145.73334 89 90 1 Victoria