Hydraena velvetina, Perkins, 2011

Perkins, Philip D., 2011, New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944, Zootaxa 2944 (1), pp. 1-417 : 67-68

Hydraena velvetina , new species

( Figs. 106 , 108 , 479 )

Type Material. Holotype (male): Eastern Highlands Province: Purosa Valley, nr. Okapa , on submerged stones, [GE est.] 1500–1700 m, 6° 32' S, 145° 37' E, 8 ii 1965, M. E. Bacchus (MEB 182a) ( NHM) . Paratypes (13): Eastern Highlands Province: Wanitabi Valley, nr. Okapa , ex muddy gravel banks of small shaded stream, 1524 m, 6° 32' S, 145° 37' E, 5 ii 1965, M. E. Bacchus (MEB 177a) (10 NHM) ; Morobe Province: Herzog Mts., Vagau [Wagau], ex gravel banks of small clear river in dense forest, 1220 m, 6° 48' S, 146° 48' E, 6 i 1965, M. E. Bacchus (MEB 140a) (1 NHM) ; Herzog Mts., Vagau [Wagau], ex leaves caught among rocks in shallow clear swift river, 1220 m, 6° 48' S, 146° 48' E, 9 i 1965, M. E. Bacchus (MEB 147a) (2 NHM) .

Differential Diagnosis. Immediately differentiated from other members of the Velvetina group by the dorsal color, the comparatively wide pronotum having a piceous fascia bordered by testaceous bands in front and back (color band ratios ca. 5/15/4) ( Fig. 106 ). In addition, the elytra, when viewed posteriorly, do not form an angle with one another. The aedeagus of H. velvetina is perhaps best compared with that of H. bubulla ( Figs. 108 , 113), but the two differ markedly in many ways, and externally the two species are quite distinct ( Figs. 106 , 111 ).

Description. Size: holotype (length/width, mm): body (length to elytral apices) 1.50/0.60; head 0.24/0.33; pronotum 0.36/0.43, PA 0.36, PB 0.34; elytra 0.90/0.60. Dorsum of head piceous; pronotum testaceous in front of and behind piceous fascia, ratios of color bands, as measured in midline, ca. 5/15/4; elytra brown; legs light brown to testaceous; maxillary palpi testaceous.

Frons punctures ca. 1xef; interstices shining, 1–4xpd. Clypeus microreticulate laterally, very finely sparsely punctate medially. Mentum slightly concave, very sparsely very finely punctulate, strongly shining; postmentum effacedly micropunctulate in median concavity. Genae raised, shining, with tiny median pit-like fovea, without posterior ridge. Pronotum cordiform, anterior margin straight or slightly arcuate; punctures on disc ca. 1xpd those of frons, interstices shining, 1–2xpd, punctures slightly larger and denser at anterior and posterior; PF1 shallow; PF2 deep, large, oval, oblique, very shallowly confluent, together forming U-shaped impression; PF3 deep; PF4 moderately deep.

Elytra convex, summit of posterior declivity at or very near midlength; lateral explanate margins moderately wide; on basal 1/3 punctures ca. 1xpd largest pronotal punctures, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 1–2xpd, as are interstices between punctures of a row. Apices in dorsal aspect conjointly rounded, in posterior aspect margins do not form angle with one another.

P1 laminate; median carina sinuate in profile. P2 raised, l/w ca. 2/1, sides slightly converging toward apex. Plaques absent, hydrofuge pubescence longest on raised sides of large, deep median depression. AIS width at straight posterior margin ca. 2x P2. All legs long and moderately slender. Profemur (male) without tubercle next to trochanter; protibia straight, medial margin gradually widening from base to about midlength, then emarginate to apex, widest point with large spine, emargination with row of short spines. Meso- and metatibiae straight. Abdominal apex symmetrical; last tergite (male) notched. Aedeagus ( Fig. 108 ) markedly arcuate in lateral view; parameres originating distally on main piece; distal piece comparatively small and simplified.

Etymology. Named in reference to the totally pubescent metaventrite.

Distribution. Currently known from eastern Area 1, and the Herzog Mts. in Area 6; elevation range 1220– 1700 m ( Fig. 479 ).

Figures

FIGURE 106. Hydraena velvetina, holotype, dorsal and lateral habitus, and venter.

FIGURE 111. Hydraena bubulla, holotype, dorsal and lateral habitus, and venter.

FIGURES 108–109. Aedeagi of holotypes. 108. H. velvetina. 109. H. ibalimi.

FIGURES 479–482. Geographical distributions of Hydraena species.