Hydraena storeyi, 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 : 85-86

Hydraena storeyi new species

(Figs. 138, 141, 262)

Type Material. Holotype (male): Queensland, Cow Bay , N of Daintree River, MDPI intercept trap site No. 11, 16° 13' S, 145° 27' E, 6 January–5 February 1988, Storey & Cunningham. Deposited in the QMBA . Paratypes (6): Queensland, Same locality as holotype, 14 December 1987 – 6 January 1988, Storey & Cunningham (1 QPIM) ; same data as holotype, 6 February–23 March 1988, Storey & Cunningham (1 QPIM) ; Emu Creek , 20 km S. Mareeba, 16° 58' S, 145° 25' E, 20 October 1990, D. Larson (4 MCZ) .

Differential Diagnosis. Similar to H. intraangulata in body length, dorsal sculpture, and plaque shape (Figs. 141, 142); differing therefrom by the narrower body form, the less truncate elytral apices, and the darker pronotum. The aedeagi of the two species also show a rather close relationship, but distinctively differ in many details (Figs. 138, 140).

Description. Size (length/width, mm) holotype: body (length to elytral apices) 1.44/0.58; head 0.24/ 0.36; pronotum 0.36/0.47, PA 0.39, PB 0.42; elytra 0.82/0.58. Head dark brown to piceous; pronotum brown with large, dark brown to piceous, diffusely margined macula; elytra dark brown; legs brown; maxillary palpi testaceous, tip not darker.

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

Elytral punctures ca. 2xpd of largest pronotal punctures; punctures becoming smaller and shallower over posterior declivity. 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 strong angle with one another.

Ratios of P2 width and plaque shape (P2/w/l/s) ca. 3/2/7/3. P1 laminate; median carina weakly angulate in profile. P2 narrow, l/w ca. 2/1, sides parallel, apex blunt. Plaques located in posterior 1/2 of metaventrite on sides of deep median, narrow subtriangular depression; plaques weakly raised, straight, tapering and converging 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 and weakly emarginate on medial margin. Last sternite with small off-center lobe; last tergite with deep, off-center notch, located opposite sternite lobe.

Aedeagus (Fig. 138) main-piece with strong basal process, also angulate near distal end, with sharp, thin, blade-like process directed toward left side; distal piece with three or four moderately complicated lobes, and long, sinuate, gonopore-bearing flagellum; left paramere slender, tapering apically, ventral margin with row of about seven setae; right paramere narrow, setae in three groups, about eight setae in row along ventral margin, about four setae apically, and about three setae on dorsal margin; large seta, flat and widened apically, on dorsal surface of main-piece. Female last tergite with three incisions, delimiting four lobes, setae slender, tapering.

Etymology. Named in honor of the collector, Ross Storey.

Distribution. Currently known from northeastern Queensland (Fig. 262).

Remarks. The two males from Emu Creek have the aedeagal process that is to the left side of the flagellum (ventral view) shaped slightly differently than that of the holotype. The other curvatures and shapes are consistent with those of the holotype aedeagus.