Hydraena hypipamee, 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 : 68

Hydraena hypipamee new species

(Figs. 100, 103, 260)

Type Material. Holotype (male): Queensland, Mt. Hypipamee National Park , 14 km SW Malanda, elev. 960 m, rainforest, streamside litter, 17° 25' S, 145° 29' E, 24 July 1982, S. & J. Peck. Deposited in the ANIC.

Differential Diagnosis. Similar to H. biimpressa in body size, the large, deep pronotal foveae PF2, and dorsal punctation ( Figs. 60 , 100); differing therefrom in the testaceous and slightly more transverse pronotum, the larger elytra, and the raised, distinct plaques. The aedeagi of the two species distinctively differ ( Figs. 62 , 103).

Description. Size (length/width, mm) holotype: body (length to elytral apices) 1.37/0.64; head 0.25/ 0.35; pronotum 0.31/0.45, PA 0.36, PB 0.36; elytra 0.87/0.64. Dorsum bicolored, labrum, clypeus and pronotum testaceous, frons and elytra dark brown; legs brown; maxillary palpi testaceous, tip not darker.

Frons punctures slightly less than 1xef; interstices shining, 2–4xpd. Clypeus microreticulate laterally, finely sparsely punctate medially. Mentum shining, very finely sparsely punctate; postmentum microreticulate. Genae raised, lacking posterior ridge. Pronotum cordiform, anterior margin emarginate; punctures on discal relief very fine and sparse, interstices strongly shining, ca. 3–6xpd, punctures much larger and denser anteriorly and posteriorly, interstices ca. 1xpd; PF1 united to form shallow transverse impression across anteromedian 1/3 of pronotal disc; PF2 deep, large, oval, oblique, each larger than area separating them; PF3 and PF4 moderately deep.

Elytra very convex, especially over posterior declivity; on basal 1/3 punctures large ca. 1xpd largest pronotal punctures, punctures becoming much smaller over posterior declivity. Intervals not raised, shining, width over basal 1/3 1xpd or less, interstices between punctures of a row larger, ca. 2–3xpd. Apices in dorsal aspect conjointly, moderately sharply rounded, in posterior aspect margins do not form angle with one another.

Ratios of P2 width and plaque shape (P2/w/l/s) ca. 4/1/4/5. P1 narrow, not laminate, median carina very weakly angulate in profile. P2 wide, short, l/w ca. 5/4, sides weakly converging, apex blunt. Median depression triangular, continuing from base to P2, at anterior extreme delimited by raised ridge. Plaques narrow, raised, converging anteriorly, on side of posterior part of triangular median depression. AIS large, flat, width at straight posterior margin slightly greater than P2. Protibia slender, very weakly arcuate, inner surface with spine-like seta near distal 1/3. Meso- and metatibia slender, straight or very nearly so. Last sternite symmetrical; last tergite with deep apicomedian notch.

Aedeagus (Fig. 103) small and simple; main-piece with comparatively large process on right side at distal extreme; distal piece with two short processes on left side, and longer, median, gonopore-bearing process; left paramere moderately wide, with row of about eight setae on ventral margin; right paramere inserting at about same level as, and much shorter than, left paramere, with sparse setae apically. Females not yet known.

Etymology. Named in reference to the geographical distribution.

Distribution. Currently known only from the type locality in Mt. Hypipamee National Park, northeastern Queensland (Fig. 260).

Figures

FIGURES 57–60. Hydraena, dorsal and lateral habitus of holotypes. —57. H. hynesi. —58. H. monteithi. —59. H. billi. —60. H. biimpressa.

FIGURES 61–64. Hydraena, aedeagi of holotypes. —61. H. billi. —62. H. biimpressa. —63. H. billi (after Zwick 1977). —64. H. monteithi.