Hydraena finniganensis, 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 : 87-88

Hydraena finniganensis new species

(Figs. 143, 145, 258)

Type Material. Holotype (male): Queensland, Gap Creek , 5 km ESE Mt. Finnigan, 15° 50' S, 145° 20' E, 13–16 May 1981, I. D. Naumann. Deposited in the ANIC.

Differential Diagnosis. Similar to H. capetribensis in body size and dorsal sculpture (Figs. 136, 143); differing therefrom by the slightly more transverse pronotum, the slightly stronger pronotal microreticulation, and the narrower, more widely spaced plaques. The aedeagi of the two species markedly differ (Figs. 139, 145).

Description. Size (length/width, mm) holotype: body (length to elytral apices) 1.46/0.61; head 0.23/ 0.35; pronotum 0.33/0.49, PA 0.38, PB 0.42; elytra 0.87/0.61. Head dark brown, margins of clypeus slightly lighter; pronotum testaceous with large, brown, diffusely margined macula; elytra dark brown; legs brown; maxillary palpi testaceous, tip not darker.

Head finely microreticulate, except on center of frons disc. Frons punctures slightly less than 1xef; interstices shining on center of disc, dull laterally, 1–3xpd. Clypeus microreticulate laterally, finely sparsely punctate medially. Mentum and postmentum weakly shining, very finely sparsely punctate. Genae weakly raised, lacking posterior ridge. Pronotum microreticulate; punctures on disc ca. 2xpd those of frons, interstices dull, 1–3xpd, punctures; punctures anteriorly and posteriorly only slightly larger than those on disc, interstices ca. 1xpd; PF1 and PF4 absent; PF2 shallow; PF3 shallow, broad.

Elytral punctures ca. 1–2xpd of largest pronotal punctures. Intervals not raised, shining, width about 1xpd, as are interstices between punctures of a row. Apices in dorsal aspect conjointly rounded, in posterior aspect margins form moderately strong angle with one another.

Ratios of P2 width and plaque shape (P2/w/l/s) ca. 2/2/7/3. P1 laminate; median carina weakly angulate in profile. P2 narrow, l/w ca. 2/1, sides parallel or weakly converging, apex blunt. Plaques located in posterior 1/2 of metaventrite on sides of deep median depression, plaques straight, converging and tapering anteriorly. AIS flat, width at arcuate posterior margin ca. 2x P2. Profemur with minute sharp tubercle on medial surface near basal 1/3; protibia very weakly arcuate, gradually increasing in width from base to apex; mesotibia slender, straight; metatibia slender, very weakly arcuate. Last sternite with small off-center lobe; last tergite with small, apical, slightly off-center concavity, located opposite sternite lobe.

Aedeagus (Fig. 145) main-piece with large basoventral process, and produced in small lobe on right side near midlength, concealing most of right paramere in ventral view; distal piece (ventral view) with two large pointed processes produced toward left side, between which are a much smaller process and the gonoporebearing process; left paramere very wide, ventral margin markedly produced, with three groups of setae, about twelve setae in row on ventral lobe (not on margin), about seven apically, and about two on dorsal margin; right paramere narrow basally, markedly widened in distal 1/2, with setae in three groups; large, hook-shaped seta on dorsal surface of main-piece. Females not yet known.

Etymology. Named in reference to the geographical distribution.

Distribution. Currently known only from the type locality near Mt. Finnigan, northern Queensland (Fig. 258).