Hydraena fundaequalis, 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 : 118-119

Hydraena fundaequalis new species

(Figs. 202, 203, 257)

Type Material. Holotype (male): Victoria, Simpson Creek , 12 km SW Orbost, 37° 44' S, 148° 20' E, 16 January 1997, C. Watts. Deposited in the SAMA . Paratype: New South Wales, Unumgar S. F. (nr. Grevillia), Coxs Rd. , subtropical rainforest, flight intercept (window) trap, FMHD #87-175 , elev. 580 m, 28° 27' S, 152° 45' E, 2–11 January 1987, A. Newton & M. Thayer (789) (1 ANIC) .

Differential Diagnosis. Recognized from other members of the trapezoidalis Group by the narrower pronotum, the more coarsely punctate frons and pronotum, the more abrupt posterior declivity of the elytra, and, in males, the decumbent brush of setae on the metatibia (Fig. 203). The aedeagus is very distinctive (Fig. 202).

Description. Size (length/width, mm) holotype: body (length to elytral apices) 1.63/0.69; head 0.23/ 0.37; pronotum 0.42/0.51, PA 0.42, PB 0.51; elytra 0.99/0.69. Head dark brown to piceous; pronotum with large dark brown macula surrounded by testaceous; elytra dark brown; legs brown; maxillary palpi testaceous. Dorsum strongly shining.

Frons punctures comparatively large, ca. 2xef, interstices ca. 1xpd, punctures fairly uniform in size across frons, not distinctly smaller on disc. Clypeus very finely sparsely punctate on disc, very weakly, effacedly microreticulate laterally. Mentum shining, very finely sparsely punctate; postmentum microreticulate. Genae raised, lacking posterior ridge. Pronotum moderately finely, sparsely punctate on disc, punctures smaller than frons punctures, punctures slightly larger anteriorly and posteriorly; PF1 and PF4 absent; PF2 extremely shallow, almost absent; PF3 shallow, broad.

Elytral punctures fine and sparse, ca. 1xpd those on frons disc. Intervals not raised, strongly shining. Apices in dorsal aspect conjointly rounded, in posterior aspect margins form weak angle with one another.

Ratios of P2 width and plaque shape (P2/w/l/s) ca. 3/2/8/3. P1 laminate; median carina weakly sinuate in profile. P2 short, moderately wide, l/w ca. 3/3, sides parallel or nearly so, apex blunt. Plaques large, tapering anteriorly, convergent but not confluent anteriorly, located on sides of deep median triangular depression. AIS flat, width at arcuate posterior margin less than 2x P2. Protibia gradually increasing in width to about distal 2/ 3, then excavate on medial margin, a short spine at base of excavation; mesotibia simple; metatibia slender, medial margin weakly emarginate and bearing brush of sparse, moderately short setae over distal 3/4. Last sternite very slightly asymmetrical; last tergite with small slightly off-center concavity.

Aedeagus (Fig. 202) twisted counter clockwise in relation to very large, asymmetrical basal opening, hence right paramere visible in lateral view but not ventral view; main-piece with short, strong process on right side at apex; distal piece with short gonopore bearing flagellum, and several large lobes; left paramere longer and much wider than right, straight, with about seven thick setae in row along ventral margin, and two groups of two very short fine setae on dorsal margin; right paramere inserting distal to insertion of left paramere, slightly arcuate, with setae at rounded, slightly widened, apex. Females not yet known.

Etymology. Named in reference to the wide pronotal base, and the equal measurements of length and apical width.

Distribution. Currently known from two widely separated localities, one each in southeastern Victoria and northeastern New South Wales (Fig. 257).