Hydraena tiara, 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 : 64

Hydraena tiara , new species

Figs. 46 (habitus), 48 (aedeagus), 88 (map)

Type material. Holotype (male): South Africa: Mpumalanga Province, Vaal River System, Vaal River where crossed by Ermelo-Lake Chrissie Road , VAL Stn. 1070P, 26° 21' S, 30° 6' E, 21 iii 1960, F. M. Chutter ( AMG) . Paratypes (34): Lesotho: Luteni River , flood debris, 29° 24' S, 29° 29' E, 12 iii 1976, Endrödy-Younga (#1073) (1 TMSA) ; South Africa: Eastern Cape Province, Elliot , small muddy, weedy stream, 30° 55' S, 26° 41' E, 27 iii 1954, J. Balfour-Browne (103) (1 BMNH) ; KwaZulu-Natal Province, Karkloof Grassveld , floating debries, 29° 19' S, 30° 15' E, 12 ix 1989, Endrödy-Younga & Klimaszewski (#2753) (5 TMSA) ; Umzimkulu River at The Rocks , marg. veg., NAT 67T-V, 29° 49' S, 29° 31' E, 15 vii 1972, collector unknown (1 AMG) ; Zululand, Nqutu , mountain stream, 28° 12' S, 30° 40' E, 14–30 ix 1950, A. H. Newton (1 AMG) ; Mpumalanga Province, Vaal River System, VAL Stn. 743X, 26° 17' S, 30° 3' E, 22 vii 1959, F. M. Chutter (3 AMG) ; Vaal River System, VAL Stn. 799E, 26° 33' S, 30° 12' E, 20 viii 1959, F. M. Chutter (2 AMG) ; Vaal River System, VAL Stn. 834R, 26° 42' S, 30° 5' E, 10 xi 1959, F. M. Chutter (1 AMG) ; 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) (6 BMNH) ; Zimbabwe: Salisbury: Borradaile , eutrophic pond, 17° 50' S, 31° 5' E, 1–30 v 1959, J. S. Weir (1 BMNH) ; Salisbury ( Highlands ), grass along marsh, 17° 50' S, 31° 5' E, 4 xi 1960, I. M. Newell (5027) (12 MCZ) .

Differential diagnosis. This species has coarse dorsal punctation, with a rather coarse and short seta in each puncture. The elytra are weakly emarginate on the sides, and the explanate margins are moderately wide ( Fig. 46 ). The metaventral plaques are subcarinate, with the length equal to the separation (ratios 1/0.5/5/5). The aedeagus ( Fig. 48 ) does not suggest placement in one of the groups, and should be examined for reliable determinations.

Description. Size: holotype (length/width, mm): body (length to elytral apices) 1.39/0.63; head 0.30/0.36; pronotum 0.34/0.52, PA 0.40, PB 0.45; elytra 0.87/0.63.

Dorsum of head dark brown to piceous; pronotum light brown around dark brown macula; elytra brown; legs brown; maxillary palpi testaceous, except distal ½ of last palpomere slightly darker. Frons punctures ca. 2xef, larger and 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, interstices shining; postmentum punctate. Genae raised, shining, without posterior ridge.

Pronotum laterally slightly emarginate in front of and behind middle; anterior margin straight behind eyes, emarginate behind frons, scintilla absent; punctures on disc much larger and deeper than those of frons, interstices shining, 0.5–3xpd, punctures larger and denser at anterior and posterior; PF1 absent; PF2 very shallow; PF3 shallow; PF4 very shallow or obsolete.

Elytra weakly arcuate laterally behind midlength, very weakly emarginate in front of midlength; summit of posterior declivity at ca. posterior 1/3; lateral explanate margin moderately wide; on basal 1/3 punctures ca. 2xpd largest pronotal punctures, punctures becoming finer and more widely spaced toward posterior. Intervals not raised, shining, on basal 1/3 ca. 1–2xpd, as are interstices between punctures of a row. Apices in dorsal aspect weakly separately rounded, in posterior aspect margins forming deep angle with one another.

Ratios of P2 width and plaque shape (P2/w/l/s) ca. 1/0.5/5/5. P1 laminate; median carina sinuate in profile. P2 l/w ca. 4/1, sides slightly diverging toward blunt apex, apex raised slightly above mesoventral intercoxal process. Plaques narrow, slightly converging toward one another anteriorly, weakly raised, subcarinate, margins not strongly demarcated, located at sides of moderately deep median depression. Metaventrite with low midlongitudinal carina between intercoxal process and median depression. AIS with arcuate narrow groove paralleling anterior margin, minute tubercle behind groove; AIS width at slightly arcuate posterior margin ca. 2x P2. All tibiae slender, straight. Abdominal apex very slightly asymmetrical; last tergite with slightly off center notch. Female (microslide mount, n=1): last tergite moderately broadly rounded, with minute apicomedian notch, ca. 22 hooked setae, some contiguous; 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 cap-like shape of the distal part of the aedeagus.

Distribution. A rather wide distribution, from Eastern Cape Province northward to Zimbabwe ( Fig. 88 ).

Figures

FIGURE 46. Hydraena tiara, holotype, dorsal and lateral habitus.

FIGURES 48–49. Aedeagi of holotypes.

FIGURES 85–88. Geographical distributions of Hydraena species.