Hydraena luminicollis, 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 : 38-39

Hydraena luminicollis new species

( Figs. 48 , 55 , 259)

Type Material. Holotype (male): Queensland, Lamington N. P., stream at head of Moran's Falls , ex. decaying leaves on bedrock at stream margin, 28° 14' S, 153° 8' E, 2 January 1998, P. D. Perkins. Deposited in the QMBA . Paratypes (189): New South Wales, Dorrigo N. P., Callicoma Falls , wet leaves and flood debris, elev. 750 m, 30° 20' S, 152° 24' E, 5 March 1980, A. Newton & M. Thayer (1 USNM) ; Wiangaree SF, Brindle Creek , wet leaves and flood debris, subtrop. forest, elev. 740 m, 28° 22' S, 153° 0' E, 29 February–3 March 1980, A. Newton & M. Thayer (182 USNM) ; Wiangaree SF, Isaksson Ridge , berl. forest leaf & log litter, N. moorei rainfor., elev. 1050 m, 28° 22' S, 153° 0' E, 29 February–3 March 1980, A. Newton & M. Thayer (6 USNM) ; Queensland, 40 km SSE Brisbane, Mt. Tambourine N. P., Cedar Creek , 27° 55' S, 153° 11' E, 22 August 2004, M. A. Jäch (AU 4) (11 NMW) ; 90 km SW Brisbane, 40 km NE Warwick , 28° 3' S, 152° 22' E, 26 August 2004, M. A. Jäch (AU 17) (1 NMW) ; Bunya Mtns. N. P., Barker Creek, downstream of Little Falls , ex decaying leaves, drift, 26° 52' S, 151° 35' E, 3 February 1998, P. D. Perkins (1 MCZ) ; Bunya Mts. , 26° 51' S, 151° 34' E, 16 October 1973, Neboiss (1 ANIC) ; Lamington N. P., Moran’s Creek , 80 km S Brisbane, elev. 760–820 m, 28° 14' S, 153° 8' E, 24 August 2004, M. A. Jäch (AU 9) (18 NMW) ; Lamington N. P., stream at head of Moran's Falls , ex. decaying leaves on bedrock at stream margin, 28° 14' S, 153° 8' E, 2 January 1998, P. D. Perkins (7 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. Similar to H. antaria and H. spinissima in body size, dorsal punctation, and general coloration; differing from both by the wider and completely testaceous pronotum ( Figs. 45, 47, 48 ); additionally differing from H. antaria by the shorter, non-carinate plaques, and from H. spinissima by the pronotal shape and more convex elytra. Based on aedeagal similarities, H. luminicollis is clearly more closely related to H. antaria than to H. spinissima ( Figs. 52 , 53, 55 ).

Description. Size (length/width, mm) holotype: body (length to elytral apices) 1.59/0.68; head 0.27/ 0.38; pronotum 0.42/0.53, PA 0.42, PB 0.46; elytra 0.94/0.68. Head dark brown to piceous, lateral areas of frons lighter; labrum and mentum testaceous; pronotum testaceous; elytra mostly dark brown, shoulders and posterior 1/2 light brown to testaceous; legs and palpi testaceous, tip of palpi not darker.

Frons punctures ca. 1xef; interstices shining, 3–5xpd. 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, anteriorly and posteriorly 1–2xpd, on disc 2–4xpd; PF1 and PF4 absent; PF2 moderately deep; PF3 moderately deep, broad.

Elytral punctures slightly smaller than largest pronotal punctures. Intervals not raised, shining, width about 2xpd, as are interstices between punctures of a row. Apices in dorsal aspect conjointly rounded, in posterior aspect margins form very weak angle with one another.

Ratios of P2 width and plaque shape (P2/w/l/s) ca. 2/2/5/6. P1 laminate; median carina angulate in profile. P2 narrow, l/w ca. 5/2, sides parallel, apex blunt. Plaques parallel or nearly so, slightly raised, located in posterior 1/2 of metaventrite on sides of deep median depression. AIS flat, width at arcuate posterior margin 3x P2. Protibia gradually widened to about distal 1/4, then markedly excavate, a prominent spine at base of excavation; mesotibia slender; metatibia slender, weakly emarginate and flattened on medial margin for most of length, small tuft of setae at apex. Last tergite with circular concavity.

Aedeagus ( Fig. 55 ) main-piece very wide in lateral view, distally with large process on right side joined to median enlargement that broadly abuts lobe of distal piece; distal piece left side (ventral view) with two or three rounded lobes and one curving process; left paramere narrowed apically, setae apically and along distal 1/2 of ventral margin, and second group of very short setae on dorsal margin; right paramere deeply bifid, setae in three groups. Female last tergite with apicomedian incision delimiting two lobes, setae slender, tapering.

Etymology. Named in reference to the bright pronotum.

Distribution. Currently known from northern New South Wales and southernmost Queensland (Fig. 259).

Figures

FIGURES 45–48. Hydraena, aedeagi of holotypes. —45. H. spinissima. —46. H. dorrigoensis. —47. H. antaria. —48. H. luminicollis.

FIGURES 53–56. Hydraena, aedeagi of holotypes. —53. H. antaria. —54. H. hynesi. —55. H. luminicollis. —56. H. hynesi (after Zwick 1977).

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