Hydraena mpumalanga, 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 : 43

Hydraena mpumalanga , new species

Figs. 30 (habitus), 32 (aedeagus), 84 (map)

Type material. Holotype (male): South Africa: Mpumalanga Province, N. Transvaal, Soutpansberg, Entabeni, shore washing, 22° 59' S, 30° 15' E, 21 iv 1976, Endrödy-Younga (#1136) ( TMSA) . Paratypes (191): South Africa: Mpumalanga Province, Louis Trich.–Vivo , airplankton, 23° 1' S, 29° 42' E, 22 iv 1976, Endrödy-Younga (#1139) (2 TMSA) ; N. Transvaal, Entabeni Forest Reserve , airplankton, forest, 22° 59' S, 30° 15' E, 21 iv 1976, Endrödy-Younga (#1137) (4 TMSA) ; N. Transvaal, Louis Trichardt , 22k W., river stones, 23° 2' S, 29° 40' E, 1–5 iv 1976, Endrödy-Younga & L. Schulze (#1125) (2 TMSA) ; N. Transvaal, Soutpansberg, Entabeni , river stones, 22° 59' S, 30° 15' E, 21 iv 1976, Endrödy-Younga (#1135) (35 TMSA) ; N. Transvaal, Soutpansberg, Entabeni , shore washing, 22° 59' S, 30° 15' E, 21 iv 1976, Endrödy-Younga (#1136) (123 TMSA) ; Uitsuk , window trap, 25° 15' S, 30° 33' E, 15 xii 1986, Endrödy-Younga (#2390) (2 TMSA) ; Zoutpansberg Dist., Khalava: Mutale River , in side gravels and muddy pools, elev. 914.4 m, 22° 58' S, 30° 15' E, 24 iv 1954, J. Balfour-Browne (191) (7 BMNH) ; Zoutpansberg; Look Out, Hanglip District , in clear rapid stream with sandy bottom, elev. 1340 m, 22° 58' S, 30° 15' E, 23 iv 1954, J. Balfour-Browne (185) (23 BMNH) .

Differential diagnosis. Quite similar in dorsal habitus to H. zimbabwensis ( Figs. 27 , 30 ); differing therefrom in slightly larger body size (ca. 1.37 vs. 1.42 mm), longer elytra compared to length of the pronotum, and very narrow, elongate instead of oval metaventral plaques. The aedeagi also show a relationship in basic form, while differing in several details ( Figs. 29 , 32 ).

Description. Size: holotype (length/width, mm): body (length to elytral apices) 1.42/0.60; head 0.22/0.36; pronotum 0.33/0.47, PA 0.38, PB 0.42; elytra 0.87/0.60.

Dorsum of head dark brown to piceous; pronotum dark brown near margins, gradually grading to piceous on disc; elytra dark brown; legs brown; maxillary palpi light brown.

Frons punctures ca. 1xef, denser near eyes than medially; interstices weakly shining, 0.5–1xpd laterally, 1– 2xpd medially. Clypeus mcr laterally, very finely sparsely punctulate medially. Mentum moderately densely finely punctulate, dull; postmentum densely punctulate, puncture contiguous, dull. Genae raised, shining, without posterior ridge.

Pronotum laterally slightly emarginate behind middle; anterior margin straight behind eyes, emarginate behind frons, scintilla absent; punctures on disc slightly larger and deeper than those of frons, interstices shining, 0.5– 2xpd, punctures denser at anterior and posterior; PF1 absent; PF2 moderately deep; PF3 deep; PF4 shallow.

Elytra weakly arcuate laterally behind midlength; summit of posterior declivity at ca. midlength; lateral explanate margin moderately wide; on basal 1/3 punctures ca. 1xpd largest pronotal punctures, punctures becoming finer and more widely spaced toward posterior. Intervals not raised, shining, on basal 1/3 ca. 1xpd, as are interstices between punctures of a row. Apices in dorsal aspect conjointly rounded, in posterior aspect margins forming shallow angle with one another.

Ratios of P2 width and plaque shape (P2/w/l/s) ca. 2/0.5/5/4. P1 laminate; median carina sinuate in profile. P2 l/w ca. 2/1, sides slightly diverging toward blunt apex, apex raised slightly above mesoventral intercoxal process. Plaques very narrow lines, margins not strongly demarcated, slightly converging toward one another anteriorly, 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. 1.5x P2. All tibiae slender, straight; protibiae widest at ca. midlength, inner surface slightly emarginate in distal 1/2. Abdominal apex symmetrical; last tergite with apicomedian notch. Female (microslide mount, n=1): last tergite moderately broadly rounded, with minute apicomedian notch, ca. 24 slender setae, widely separated, very weakly if at all hooked, set back from margin ½ length of setae, or more; gonocoxite not midlongitudinally divided, apical margin moderately broadly rounded, low transverse ridge evident at border of microreticulation; spermatheca simple, type C shape.

Etymology. Named in reference to the geographical distribution.

Distribution. Currently known only from Mpumalanga Province, South Africa ( Fig. 84 ).

Figures

FIGURE 27. Hydraena zimbabwensis, holotype, dorsal and lateral habitus.

FIGURE 30. Hydraena mpumalanga, holotype, dorsal and lateral habitus.

FIGURES 28–29. Aedeagi of holotypes.

FIGURES 32–33. Aedeagi of holotypes.

FIGURES 81–84. Geographical distributions of Hydraena species.