Hydraena cunninghamensis, 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 : 67

Hydraena cunninghamensis new species

(Figs. 99, 102, 261)

Type Material. Holotype (male): Queensland, Main Range National Park, Cunningham's Gap, Gap Creek , elev. 700 m, ex. bare rocks in splash zone, 28° 3' S, 152° 24' E, 21 January 1998, P. D. Perkins. Deposited in the QMBA . Paratype: Same data as holotype (1 female QMBA) .

Differential Diagnosis. Similar to H. hynesi in body size, coloration, and the confluent pronotal foveae PF2, forming a U-shaped impression ( Figs. 57 , 99); differing therefrom by coarser pronotal punctures (compared to those of the frons), and the wider plaques. The aedeagi of the two species distinctively differ ( Figs. 54, 56 , 102).

Description. Size (length/width, mm) holotype: body (length to elytral apices) 1.42/0.63; head 0.23/ 0.35; pronotum 0.33/0.46, PA 0.38, PB 0.38; elytra 0.85/0.63. Dorsum bicolored, clypeus and pronotum testaceous, frons and elytra brown except diffuse lighter area on elytral disc, legs and maxillary palpi testaceous (but see notes).

Frons punctures ca. 1xef; interstices shining, 1–3xpd. 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 disc ca. 2– 3xpd than those of frons, interstices shining, 2–4xpd, punctures larger and denser anteriorly and posteriorly, interstices sometimes narrow walls forming reticulate pattern; PF1 united to form shallow transverse impression across anterior 1/3 of pronotal disc; PF2 well impressed, oval, oblique, shallowly united in middle, conjointly forming U-shaped impression; PF3 moderately shallow, broad; PF4 very shallow.

Elytra very convex, especially over posterior declivity; on basal 1/3 punctures large, ca. 1–1.5xpd 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 slightly larger. 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. 3/1/5/4. P1 narrow, not laminate, median carina straight, or nearly so, in lateral view. P2 as wide as area separating anterior extreme of plaques, short, l/w ca. 3/2, sides parallel, apex blunt. Plaques narrow, located in posterior 7/10 of metaventrite on sides of deep median, triangular depression, plaques weakly convergent anteriorly, separation anteriorly 1x P2, separation posteriorly almost 2x P2. Low, very short midlongitudinal ridge between mesoventral intercoxal process and plaques. AIS large, flat, width at straight posterior margin 2x P2. Protibia slender, weakly arcuate, inner surface with tiny narrow triangular process near distal 1/3. Meso- and metatibia slender, straight or very nearly so. Last sternite symmetrical; last tergite with deep apicomedian notch.

Aedeagus (Fig. 102) small and simple; main-piece with process on right side at distal extreme; distal piece with two short processes on left side, and longer, median, gonopore-bearing process; left paramere medially displaced, arcuate, with row of about six setae on ventral margin; right paramere inserting at about same level as, and much shorter than, left paramere, with sparse setae apically. Female last tergite with three incisions, widely spaced, apicomedian incision smaller, two lobes formed by incisions not markedly arcuate.

Etymology. Named in reference to the geographical distribution.

Distribution. Currently known only from Cunningham's Gap in the Main Range National Park (Fig. 261).

Remarks. Plaque shape is similar in the sexes.

Figures

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

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