Hydraena textila, 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 : 83-84

Hydraena textila new species

(Figs. 135, 137, 255)

Type Material. Holotype (male): Queensland, Laceys Creek , 10 km SE El Arish, elev. 40 m, flight intercept trap, rainforest, 27° 11' S, 152° 47' E, 23 June–5 August 1982, S. & J. Peck. Deposited in the ANIC.

Differential Diagnosis. Similar to H. capetribensis in body form and dorsal sculpture (Figs. 135, 136); differing therefrom by the slightly smaller size (ca. 1.41 vs. 1.45 mm), the lighter, testaceous borders surrounding the pronotal macula, and the more widely separated plaques. The aedeagi of the two species also show a relationship, but differ in significant details (Figs. 137, 139).

Description. Size (length/width, mm) holotype: body (length to elytral apices) 1.41/0.57; head 0.23/ 0.34; pronotum 0.35/0.46, PA 0.40, PB 0.40; elytra 0.83/0.57. Head dark brown; 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 ca. 1xef; interstices shining on disc, dull laterally, 1–3xpd. Clypeus microreticulate. Mentum and postmentum weakly shining, very finely sparsely punctate. Genae weakly raised, lacking posterior ridge. Pronotum finely microreticulate; punctures on disc ca. 1xpd those of frons, interstices dull, 2–4xpd, punctures; punctures anteriorly and posteriorly ca. 2xpd those on disc, interstices ca. 1–2xpd; PF1 and PF4 absent; PF2 shallow, more strongly microreticulate than disc; PF3 shallow, broad.

Elytral punctures ca. 1xpd 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. 2.5/2/5/3.5. P1 laminate; median carina weakly angulate in profile. P2 narrow, l/w ca. 2/1, sides parallel or weakly diverging, apex blunt. Plaques located in posterior 1/2 of metaventrite on sides of deep median depression, plaques very weakly, if at all, arcuate, converging slightly anteriorly, becoming gradually raised from anterior to posterior, posterior extreme raised in tiny point. 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, widest near distal 1/3; mesotibia and metatibia slender, simple. Last sternite symmetrical or nearly so; last tergite with small, apical, slightly off-center concavity.

Aedeagus (Fig. 137) main-piece with strong basal process bent toward right side, distal part of main-piece widened on right side, in ventral view concealing most of right paramere; distal piece comparatively uncomplicated, with long gonopore-bearing flagellum; left paramere angulate near basal 1/3, then tapering to apex, setae in two groups, a row of about seven setae along ventral margin, and about two setae at apex; right paramere slender, setae in two groups, a row of about eight setae along ventral margin, and about two setae at apex. Females not yet known.

Etymology. Named in reference to the microreticulate pronotum and the type locality (= weave, woven).

Distribution. Currently known only from the type locality in southeastern Queensland (Fig. 255).