Hydraena capensis, 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 : 14

Hydraena capensis , new species

Figs. 6 (habitus), 8 (aedeagus), 78 (map)

Type material. Holotype (male): South Africa: Eastern Cape Province, Chapman’s Bay , little pond, 34° 1' S, 18° 20' E, 8 vii 1903, Vanhoffen, Ernst ( ZMHB). Labels: " Capland Süsswassertümpel bei Chapmansbay 8.7.1903 Vanhöffen S. " Paratype: South Africa: Eastern Cape Province, Same data as holotype (1 ZMHB) .

Differential diagnosis. This species is slightly more coarsely punctate dorsally, and has slightly more rounded elytra than H. cooperi and H. cooperoides ( Figs. 2 , 3 , 6 ). Reliable determinations will require careful examination of the aedeagi ( Figs. 4, 5 , 8 ).

Description. Size: holotype (length/width, mm): body (length to elytral apices) 1.41/0.64; head 0.20/0.36; pronotum 0.34/0.48, PA 0.40, PB 0.47; elytra 0.90/0.64. Dorsum of head dark brown to piceous; pronotum light brown around dark brown to piceous macula; elytra brown; legs light brown; maxillary palpi testaceous.

Frons punctures ca. 1xef, larger and denser near eyes than medially; interstices weakly shining, 0.5–1xpd laterally, 0.5–2xpd medially. Clypeus mcr laterally, very finely sparsely punctulate medially. Mentum weakly concave medially, densely finely punctulate, interstices shining; postmentum punctate, with deep depression on each side. 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 ca. 1–2xpd those of frons, interstices shining, 0.5–2xpd, punctures slightly denser at anterior and posterior; PF1 absent; PF2 very shallow; PF3 shallow; PF4 very shallow or obsolete.

Elytra weakly arcuate laterally; summit of posterior declivity at ca. posterior 1/3; 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. 2xpd, as are interstices between punctures of a row. Apices in dorsal aspect weakly separately rounded, in posterior aspect margins forming shallow angle with one another.

Ratios of P2 width and plaque shape (P2/w/l/s) ca. 2/1/1/5. P1 laminate; median carina sinuate in profile. P2 l/ w ca. 2/1, sides becoming parallel toward blunt apex, apex raised slightly above mesoventral intercoxal process. Plaques very small, indistinct, oval, margins not strongly demarcated, located at sides of moderately 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. Protibiae very slightly arcuate, meso- and metatibiae straight. Abdominal apex symmetrical; last tergite with apicomedian notch. Female (microslide mount, n=1): last tergite moderately broadly rounded, without apicomedian notch, ca. 36 hooked setae in irregular row, many contiguous, no median gap; 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 the type locality ( Fig. 78 ).

Note. I am grateful to Manfred Uhlig for interpreting the locality label of the holotype.

Figures

FIGURE 2. Hydraena cooperi, holotype, dorsal and lateral habitus.

FIGURE 3. Hydraena cooperoides, holotype, dorsal and lateral habitus.

FIGURE 6. Hydraena capensis, holotype, dorsal and lateral habitus.

FIGURES 4–5. Aedeagi of holotypes of H. cooperi and H. cooperoides, and aedeagal variants of H. cooperi.

FIGURES 8–9. Aedeagi of holotypes.

FIGURES 77–78. Geographical distributions of Hydraena species.