Hydraena miniretia, 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 : 17-18

Hydraena miniretia new species

( Figs. 12 , 16 , 255)

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 . Paratypes: Queensland, Leichhardt Creek , 8 km N Bluewater, 19° 10' S, 146° 32' E, 18 December 2002, A. J. & C. H. S. Watts (3 SAMA) .

Differential Diagnosis. Similar in size, body form and plaques to H. magnetica ; differing therefrom by the microreticulate pronotal interstices and the more coarsely punctate elytral series ( Figs. 11, 12 ). The aedeagi of the two species differ distinctively ( Figs. 15, 16 ).

Description. Size (length/width, mm) holotype: body (length to elytral apices) 1.13/0.46; head 0.17/ 0.30; pronotum 0.28/0.38, PA 0.33, PB 0.34; elytra. 68/0.46. Head and large pronotal macula dark brown to piceous, margins of pronotum light brown, elytra dark brown, legs and maxillary palpi light brown to testaceous.

Head and pronotum effacedly microreticulate, weakly shining. Frons finely sparsely punctate, punctures distinctly smaller than 1xef; interstices 2–6xpd. Clypeus microreticulate. Mentum weakly shining, effacedly microreticulate and very finely sparsely punctate; postmentum microreticulate. Genae raised, lacking posterior ridge. Pronotal punctures on disc ca. 1xef, interstices dull, 2–3xpd, punctures slightly denser anteriorly and posteriorly, interstices ca. 1xpd; PF1 and PF4 absent; PF2 and PF3 shallow.

Elytral punctures about equal size of largest pronotal punctures. Intervals not raised, shining, width about 1–2xpd, 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. 2/1/5/3. P1 laminate; median carina angulate in profile. P2 moderately narrow, l/w ca. 2/1, sides parallel, apex blunt. Plaques narrow, elongate ovals, moderately widely separated and parallel to one another, not distinctly tapering anteriorly, located in posterior 1/2 of metaventrite on sides of shallow median depression. AIS flat, comparatively narrow, width at arcuate posterior margin slightly less than 2x P2. Legs simple, tibiae slender. Last sternite and last tergite simple, symmetrical.

Aedeagus ( Fig. 16 ) main-piece much wider distally than at base, with large process on apical part of right side; distal piece (ventral view) with small hook-like process on left side and weakly sclerotized, fimbriate edged, lobe on right side; parameres of about equal length, left paramere slightly widened in basal 1/2. Female last tergite with apicomedian incision delimiting two lobes, setae slender, tapering.

Etymology. Named in reference to the small size and microreticulate pronotum.

Distribution. Currently known from northeastern Queensland (Fig. 255).

Figures

FIGURES 11–14. Hydraena, dorsal and lateral habitus of holotypes. —11. H. magnetica. —12. H. miniretia. —13. H. innuda. —14. H. porchi.

FIGURES 15–18. Aedeagi of holotypes. —15. H. magnetica (after Zwick 1977). —16. H. miniretia. —17. H. innuda. —18. H. converga.