Hydraena converga, 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 : 27-28

Hydraena converga new species

( Figs. 18 , 32 , 258)

Type Material. Holotype (male): Northern Territory, Roderick Creek, Gregory N. P., Operation Raleigh , at light, 15° 38' S, 131° 22' E, 4–6 July 1986, I. Archibald. Deposited in the MAGD . Paratypes (14): Northern Territory, Border Waterhole , Musselbrook Ck. 15 km W by S of Musselbrook Mining Camp ( QLD), small rocky pools above gorge, sandy bottom, algal growth, roots in water, 18° 37' S, 137° 59' E, 14 May 1995, T . Weir (2 ANIC) ; Queensland, Musselbrook Creek , 2 km S of Musselbrook Mining Camp, large pool in rocky creek, sandy bottom, 18° 37' S, 138° 8' E, 9 May 1995, T . Weir (2 ANIC) ; Western Australia, 14 km SbyE Kalumburu Mission , CALM Site 4/3 [Western Australian Department of Conservation and Land Management], at light, open forest, 14° 25' S, 126° 40' E, 3–6 June 1988, T . A. Weir (1 ANIC); Beverly Springs, 16° 43' S, 125° 28' E, 1 September 1969, D. D. Giuliani (2 WAMP); East Kimberley, Meelarie Creek , 5 km N Drysdale Crossing, elev. 350 m, 15° 40' S, 126° 24' E, 19 June 1999, L. Hendrich (2 NMW); near Dampier Downs, 18° 31' S, 123° 27' E, 23 December 1968, D. D. Giuliani (3 WAMP); Synnot Ck., CALM Site 25/1 [Western Australian Department of Conservation and Land Management], at light, closed forest margin, 16° 31' S, 125° 16' E, 17–20 June 1988, T . A. Weir (2 ANIC) .

Differential Diagnosis. Similar in habitus to H. simplicicollis and H. brittoni ( Figs. 29–32 ); differing therefrom by the slightly coarser dorsal punctation, the thinner plaques which are narrow lines, widely separated posteriorly and converging anteriorly; and, in males, the metatibiae with a fringe of short, hair-like setae over the distal 1/2. The aedeagus differs in several respects from the aedeagi of the compared species ( Figs. 18 , 33–36 ).

Description. Size (length/width, mm) holotype: body (length to elytral apices) 1.58/0.68; head 0.25/ 0.39; pronotum 0.38/0.49, PA 0.42, PB 0.47; elytra 0.92/0.68. Head piceous, pronotum piceous on disc, dark brown anteriorly and posteriorly, elytra dark brown, legs and maxillary palpi brown, tip of last palpomere not darker.

Frons punctures ca. 1xef; interstices shining, 0.5–2xpd. Clypeus microreticulate laterally, shining and finely sparsely punctate medially. Mentum shining, very finely sparsely punctate; postmentum microreticu- late. Genae raised, lacking posterior ridge. Pronotal punctures on disc ca. 2xpd those of frons, interstices shining, 1–3xpd, punctures denser anteriorly and posteriorly, separated by narrow walls to 1xpd; PF1 and PF4 absent; PF2 very small, nearly absent; PF3 moderately deep, broad.

Elytral punctures about equal size of 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 shallow angle with one another.

Ratios of P2 width and plaque shape (P2/w/l/s) ca. 3/.3/8/5. P1 laminate; median carina slightly angulate in profile. P2 moderately wide, l/w ca. 3/4, sides parallel, apex blunt. Plaques located in posterior 0.7 of metaventrite on sides of deep median subtriangular depression, plaques very narrow lines, not raised, straight, converging, anterior separation ca. 1/2 posterior separation. No midlongitudinal carina between mesoventral intercoxal process and plaques. AIS flat, width at arcuate posterior margin slightly less than 2x P2. Protibia and mesotibia slender, simple; metatibia slender, medial margin with fringe of short, hair-like setae over distal 1/2. Last tergite with small apicomedian notch.

Aedeagus ( Fig. 18 ) main-piece with pointed process on right side about equal in length to right paramere, which is behind it; distal piece with several diagnostic processes; left paramere very wide in distal 1/2, setae sparse, long, and thin; right paramere with large lobe in basal 1/2, setae in row on ventral margin. Female last tergite with rather deep apicomedian incision delimiting two lobes, setae slender, tapering.

Etymology. Named in reference to the metaventral plaques, which are converging lines.

Distribution. Currently known from northwestern Queensland, northeastern Western Australia, and an intermediate locality in Northern Territory (Fig. 258).

Figures

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

FIGURES 29–32. Hydraena, dorsal and lateral habitus of types. —29. H. simplicicollis, lectotype male. —30. H. simplicicollis, paralectotype female. —31. H. brittoni, holotype. —32. H. converga, holotype.

FIGURES 33–36. Hydraena, aedeagi of types. —33. H. simplicicollis, lectotype. —34. H. simplicicollis, lectotype (after Zwick 1977). —35. H. brittoni, holotype. —36. H. brittoni, holotype (after Zwick 1977).