Hydraena latisoror, Published, 2007

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 : 22-23

Hydraena latisoror new species

( Figs. 21 , 26 , 255)

Type Material. Holotype (male): Queensland, Lamington N. P., stream at head of Moran's Falls , brushing boulders and bedrock at stream margin, 28° 14' S, 153° 8' E, 2 January 1998, P. D. Perkins. Deposited in the QMBA . Paratypes (9): New South Wales, Border Ranges N. P., Sheepstation Creek , ex. bare rocks in splash zone, elev. 300 m, 28° 23' S, 153° 2' E, 29 January 1998, P. D. Perkins (1 MCZ) ; Queensland, Joalah Nat. Park, Tambourine Mt.; ANIC Berl. No. 656, litter and flood debris, 27° 53' S, 153° 11' E, 23 July 1979, J. F. Lawrence (3 QMBA); Lamington N. P., Binna Burra , 28° 14' S, 153° 8' E, 10 January 2001, T . Ueno (2 KUEC); Lamington N. P., stream at head of Moran's Falls , brushing boulders and bedrock at stream margin, 28° 14' S, 153° 8' E, 2 January 1998, P. D. Perkins (2 MCZ); Natural Bridge N. P., Cave Creek, ex. bare rocks in splash zone, 28° 14' S, 153° 15' E, 31 January 1998, P. D. Perkins (1 MCZ) .

Differential Diagnosis. A very broad species, similar in this respect to H. williamensis ( Figs. 21, 22 ); differing therefrom by the more densely, more coarsely punctate dorsum, the wider mesoventral intercoxal process, and the distinct, widely spaced plaques. The aedeagi of the two species differ distinctively ( Figs. 26 , 27 ).

Description. Size (length/width, mm) holotype: body (length to elytral apices) 1.51/0.64; head 0.24/ 0.38; pronotum 0.40/0.53, PA 0.42, PB 0.45; elytra 0.87/0.64. Head dark brown; pronotal disc dark brown, surrounding areas brown; elytra dark brown; legs light brown; palpi light brown to testaceous, tip not darkened.

Frons punctures ca. 1xef; interstices shining, 1–2xpd. Clypeus microreticulate. Mentum shining, very finely sparsely punctate; postmentum microreticulate. Genae raised, lacking posterior ridge. Pronotal punctures on disc ca. 2xpd and deeper than those of frons, interstices shining, 0.5–1xpd, only slightly sparser on disc than anteriorly and posteriorly; PF1 absent; PF2 moderately deep, oblique; PF3 shallow, broad; PF4 very shallow, almost absent.

Elytral punctures ca.1xpd or slightly larger than largest pronotal punctures. Intervals not raised, shining, width ca. 0.5–1xpd, as are interstices between punctures of a row. Apices in dorsal aspect conjointly, rather sharply rounded, in posterior aspect margins form very weak angle with one another.

Ratios of P2 width and plaque shape (P2/w/l/s) ca. 2/1/5/4. P1 laminate; median carina angulate in profile. P2 narrow, l/w ca. 5/2, sides parallel or very weakly converging, apex blunt. Plaques located in posterior 1/2 of metaventrite on sides of deep median depression, parallel or nearly so, each plaque very weakly tapering anteriorly. AIS flat, width at arcuate posterior margin 2–3x P2. Protibia (male) widened to about distal 1/ 3, then markedly excavate on medial surface, a prominent spine at base of excavation; meso- and metatibiae slender, metatibia weakly arcuate, without setal brushes. Last sternite symmetrical or nearly so; last tergite with small apicomedian concavity.

Aedeagus ( Fig. 26 ) main-piece with distal extended part wide, except abruptly tapering at tip, continuing beyond distal piece; distal piece with two lobes, the right much larger than the left, the left with two processes on the outer margin; left paramere slender for most of length, widened apically, very weakly sinuate, much longer than right paramere, with cluster of about four large setae on inner margin below apex; right paramere widened apically and near midlength, with setae in one group at apex. Female last tergite with apicomedian incision delimiting two lobes, setae slender, tapering.

Etymology. "Wide sister"; named in reference to the wide body form, compared with H. tenuisoror and H. williamensis .

Distribution. Currently known from southeastern corner of Queensland and adjacent northernmost eastern New South Wales (Fig. 255).

Figures

FIGURES 19–22. Hydraena, dorsal and lateral habitus of holotypes. —19. H. millerorum. —20. H. tenuisoror. —21. H. latisoror. —22. H. williamsensis.

FIGURES 23–26. Aedeagi of holotypes. —23. H. porchi. —24. H. millerorum. —25. H. tenuisoror. —26. H. latisoror.

FIGURES 27–28. Hydraena williamsensis, aedeagi. —27. Holotype. —28. Holotype (after Zwick 1977).