Hydraena cooperoides, 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 : 11-14

Hydraena cooperoides , new species

Figs. 3 (habitus), 5 (aedeagus), 87 (map)

Type material. Holotype (male): Namibia: Naukluft River , shore washing, 24° 16' S, 16° 15' E, 10 viii 1989, Endrödy-Younga & Klimaszewski (#2644) ( TMSA) . Paratypes (799): Angola: 20 km. E. Luanda, Luanda-Catete Highway , water-hole, gravel and clay bottom, 8° 50' S, 13° 22' E, 9 x 1949, B. Malkin (10 BMNH) ; Altoplano: Ongueria , side pools above waterfall, elev. 1615 m, 15° 19' S, 13° 32' E, 12 vi 1954, J. Balfour-Browne (263) (4 BMNH) ; Ongueria , in fine sand at side of stream above cataracts, elev. 1615 m, 15° 19' S, 13° 32' E, 13 vi 1954, J. Balfour-Browne (1 BMNH) ; Da Huila, Tchivinguire, SE 1513 Ab ; H22344, 15° 10' S, 13° 21' E, 14-17 xi 1974, none given on label (4 SMW) ; Namibia: Kavango: Popa Falls , lux, 18° 7' S, 21° 35' E, 26 ii–1 iii 1992, M. Uhlig (1 ZMHB) ; Namib-Naukluft Park, Naukluft spring, spring, 24° 15' S, 16° 14' E, 28-30 xi 1997, Kirk-Spriggs & Marais (6 SMW) ; Namib-Naukluft Park, Tsams Ost , permanent mountain rivulet, shore sievings and washing, 24° 14.4' S, 16° 6.2' E, 26-28 xi 1997, M. Uhlig (2 ZMHB) ; Namib-Naukluft Park, Tsams Ost spring, spring, 24° 14' S, 16° 6' E, 26-28 xi 1997, Kirk-Spriggs & Marais (3 SMW) ; Namib-Naukluft NP: Naukluft River, Phragmites grass + leaf litter, shore washing + sievings, 24° 15.78' S, 16° 14.08' E, 29-30 xi 1997, M. Uhlig (24 ZMHB) ; Namib- Naukluft NP, Waterkloof, algae + Carex + Phragmites , shore washing, 24° 16.8' S, 16° 14.2' E, 29 xi 1997, M. Uhlig & E. Marais (1 ZMHB) ; Naukluft cascades, cascades, 24° 16' S, 16° 15' E, 12 viii 1989, Endrödy-Younga & Klimaszewski (#2648) (2 TMSA) ; Naukluft, Naukluft Park , shore washing, 24° 16' S, 16° 15' E, 26 x 1974, Endrödy-Younga (#431) (8 TMSA) ; Naukluft River , shore washing, 24° 16' S, 16° 15' E, 10 viii 1989, Endrödy- Younga & Klimaszewski (#2644) (730 TMSA) .

Additional material: Same data as holotype (~1000 TMSA) .

Differential diagnosis. Very similar in dorsal habitus and ventral characters to H. cooperi ( Figs. 2 , 3 ). The elytra are often slightly more narrowed toward the apices than in H. cooperi , and the two species are largely allopatric ( Figs. 65 , 87 ), but reliable determinations will require careful examination of the aedeagi ( Figs. 4, 5 ).

Description. Size: holotype (length/width, mm): body (length to elytral apices) 1.51/0.62; head 0.26/0.37; pronotum 0.36/0.48, PA 0.41, PB 0.46; elytra 0.95/0.62.

Dorsum of head piceous; pronotum light brown around piceous macula; elytra brown; legs light brown to testaceous; maxillary palpi testaceous.

Frons punctures ca. 1xef, larger and denser near eyes than medially; interstices shining, 0.5–1xpd laterally, 1– 4xpd medially. Clypeus mcr laterally, very finely sparsely punctulate medially. Mentum weakly concave medially, moderately densely finely punctulate, interstices shining; postmentum punctate, with deep depression on each side. 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 slightly larger than those of frons, interstices strongly shining, 1–4xpd, punctures slightly larger and 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 slightly behind midlength; lateral explanate margin narrow; 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 deep 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 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 slightly arcuate, meso- and metatibiae straight. Abdominal apex symmetrical; last tergite with apicomedian notch. Female (microslide mount, n=1): last tergite moderately sharply rounded, with minute apicomedian notch, ca. 36 hooked setae, closely set, in irregular row; gonocoxite not midlongitudinally divided, apical margin moderately sharply rounded, low transverse ridge evident at border of microreticulation; spermatheca simple, type C shape.

Etymology. Named in reference to the relationship to H. cooperi , as evidenced by the male genitalia.

Distribution. Currently known from widely separated localities in Namibia and southern Angola ( Fig. 87 ).

Figures

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

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

FIGURES 64–65. 64. All known collecting localities for southern African Hydraena. 65. Geographical distributions of Hydraena species.

FIGURES 85–88. Geographical distributions of Hydraena species.

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