Hydraena habitiva, Perkins, 2014

PERKINS, PHILIP D., 2014, A revision of the water beetle genus Hydraena Kugelann for southern Africa (Coleoptera: Hydraenidae), Zootaxa 3758 (1), pp. 1-92 : 68-69

Hydraena habitiva , new species

Figs. 54 (habitus), 56 (aedeagus), 71 (map)

Type material. Holotype (male): South Africa: Mpumalanga Province, Nelshoogte gallery forest below St., shore washing, 25° 51' S, 30° 53' E, 2 xii 1986, Endrödy-Younga (#2343) ( TMSA) . Paratypes (15): South Africa: KwaZulu-Natal Province, Karkloof Grassveld , floating debries, 29° 19' S, 30° 15' E, 12 ix 1989, Endrödy- Younga & Klimaszewski (#2753) (1 TMSA) ; Mpumalanga Province, E. Transvaal, Blyderiver Canyon , shore washing, 24° 35' S, 30° 49' E, 2 v 1981, Endrödy-Younga (#1765) (3 TMSA) ; N. Transvaal, Soutpansberg, Entabeni , shore washing, 22° 58' S, 30° 15' E, 15 iii 1973, Endrödy-Younga (#56) (1 TMSA) ; Nelshoogte gallery forest below St. , shore washing, 25° 51' S, 30° 53' E, 2 xii 1986, Endrödy-Younga (#2343) (8 TMSA) ; Uitsoek, Grootkloof ind. for., intercept trap, 62 days, 25° 15' S, 30° 33' E, 6 ii 1987, Endrödy-Younga (#2422) (2 TMSA) .

Differential diagnosis. Differentiated from other species by the combination of the subcordiform pronotum, which is slightly wider at the anterior margin than at the base, the coarse and dense pronotal punctation, the relatively small and transversely convex elytra ( Fig. 54 ), and the carinate metaventral plaques (ratios 2/0.3/5/5). The last tergite is concave in both sexes, and the female has dense, long setae lateral to the concavity, and no setae near the apicomedian notch; these characters are unique to this species. The aedeagus ( Fig. 56 ) does not readily suggest placement in one of the currently known groups.

Description. Size: holotype (length/width, mm): body (length to elytral apices) 1.50/0.63; head 0.25/0.36; pronotum 0.38/0.48, PA 0.40, PB 0.38; elytra 0.88/0.63.

Dorsum of head piceous; pronotum brown to dark brown in front of and behind piceous fascia; elytra dark brown; legs brown; maxillary palpi light brown.

Frons punctures ca. 1xef near eyes, smaller medially, denser near eyes than medially; interstices weakly shining, ca. 1xpd laterally, 1–4xpd medially. Clypeus weakly mcr laterally, very distinctly punctulate. Mentum moderately densely finely punctulate, interstices shining; postmentum punctate, with shallow depression on each side. Genae raised, shining, without posterior ridge.

Pronotum subcordiform; anterior margin straight behind eyes, emarginate behind frons, scintilla absent; moderately coarsely densely punctate, punctures on disc much larger, deeper and denser than those of frons, interstices ca. 1xpd on disc, in a few places narrow walls; punctures denser posteriorly; PF1 absent; PF2 very shallow; PF3 deep and confluent with shallow PF4.

Elytra arcuate laterally; transversely quite convex, especially at summit of posterior declivity, at ca. midlength; lateral explanate margin moderately wide; on basal 1/3 punctures slightly larger than largest pronotal punctures, punctures becoming finer and more widely spaced toward posterior. Intervals not raised, shining, on basal 1/3 ca. 0.5–1xpd, as are interstices between punctures of a row. Apices in dorsal aspect conjointly, rather sharply rounded, in posterior aspect margins do not form angle with one another.

Ratios of P2 width and plaque shape (P2/w/l/s) ca. 2/0.3/5/5. P1 laminate; median carina sinuate in profile. P2 l/w ca. 5/2, sides slightly converging toward blunt apex, apex raised slightly above mesoventral intercoxal process. Plaques carinate lines, converging toward one another anteriorly, weakly raised, subcarinate, margins not strongly demarcated, located at sides of deep median depression. Metaventrite without midlongitudinal carina between intercoxal process and median depression. AIS width at slightly arcuate posterior margin ca. 2x P2. All tibiae slender, straight. Protibiae emarginate on lower surface in distal 1/3. Abdominal apex symmetrical; last tergite concave. Female (microslide mount, n=1): last tergite medially concave, elevated area lateral to concavity with dense, long setae, apical margin of tergite with minute apicomedian notch, without setae; gonocoxite not midlongitudinally divided, apical margin moderately broadly rounded, transverse ridge evident at border of microreticulation, peaked in middle; spermatheca simple, type C shape.

Etymology. Named in reference to the distinctive habitus.

Distribution. Currently known only from Mpumalanga Province and KwaZulu-Natal Province, South Africa ( Fig. 71 ).

Figures

FIGURE 54. Hydraena habitiva, holotype, dorsal and lateral habitus.

FIGURES 56–57. Aedeagi of holotypes.

FIGURES 71–74. Geographical distributions of Hydraena species.