Hydraena humanica, 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 : 59-61

Hydraena humanica , new species

Figs. 42 (habitus), 44 (aedeagus), 72 (map)

Type material. Holotype (male): South Africa: Mpumalanga Province, E. Transvaal, Blyderiver Canyon, shore washing, 24° 35' S, 30° 49' E, 2 v 1981, Endrödy-Younga (#1765) ( TMSA) . Paratypes (104): South Africa: KwaZulu-Natal Province, Bergville, Tugela River , elev. 1158 m, 28° 44' S, 29° 21' E, 6 iv 1954, J. Balfour- Browne (148) (2 BMNH) ; Injambili (or Ntshambili) River , on inland rd. nr. Umzumbe , marginal vegetation; NAT 77R-S, elev. 2 m, 30° 31' S, 30° 37' E, 7 vi 1972, F. M. Chutter (2 AMG) ; Karkloof Grassveld , floating debries, 29° 19' S, 30° 15' E, 12 ix 1989, Endrödy-Younga & Klimaszewski (#2753) (1 TMSA) ; Mfabeni River , shore washing, 28° 5' S, 31° 0' E, 15 xii 1975, Endrödy-Younga (#979) (3 TMSA) ; nr. Bergville , small unnamed spruit, in side pools among muddy stones and sand, 28° 44' S, 29° 21' E, 4 iv 1954, J. Balfour-Browne (142) (2 BMNH) ; nr. Drummond , small stream, stony and weedy pools, elev. 457.2 m, 30° 50' S, 30° 25' E, 1 iv 1954, J. Balfour-Browne (128) (1 BMNH) ; Tugela River, Stn. TUG 66Q4, 28° 54' S, 31° 2' E ,, W. D. Oliff (2 AMG) ; Umhlungwa River on old S. coast rd., nr. Hibberdene , marginal vegetation; NAT 82N-P, elev. 3 m, 30° 34' S, 30° 32' E, 7 vi 1972, F. M. Chutter (1 AMG) ; Umzumbe River Stn. 2, where crossed by old S. coast rd., marginal vegetation; NAT 92P-R, elev. 2 m, 30° 32' S, 30° 36' E, 7 vi 1972, F. M. Chutter (2 AMG) ; Weza, Impetyene Forest , lower forest, shore washing, large and rapid forest river with stony banks, 30° 37' S, 29° 42' E, 19 ii 1989, Endrödy-Younga (#2697) (3 TMSA) ; Zululand, Nqutu , mountain stream, 28° 12' S, 30° 40' E, 2–15 vi 1951, A. H. Newton (1 AMG) ; Limpopo Province, N. Transvaal, Waterberg, Farm 223, Mogol River , flood debris, 24° 11' S, 27° 50' E, 13 ii 1976, A. Strydom, Endrödy-Younga (#1039) (4 TMSA) ; Mpumalanga Province, Bundu Inn , shore washing, 25° 28' S, 28° 55' E, 24 iii 1974, Endrödy-Younga (#304) (2 TMSA) ; E. Transvaal, Berlin F. S., gorge-edge, groundtrap with banana bait, 42 days, 24° 32' S, 30° 44' E, 23 x 1986, Endrödy-Younga (#2302) (1 TMSA) ; E. Transvaal, Blyderiver Canyon , shore washing, 24° 35' S, 30° 49' E, 2 v 1981, Endrödy-Younga (#1765) (62 TMSA) ; Klip Spruit near Witbank, Zaaihoek ; GEN, stones in current, 25° 38' S, 29° 8' E, (1 AMG) ; Nelshoogte gallery forest below St. , shore washing, 25° 51' S, 30° 53' E, 2 xii 1986, Endrödy-Younga (#2343) (2 TMSA) ; Uitsoek, Grootkloof ind. for., intercept trap, 62 days, 25° 15' S, 30° 33' E, 6 ii 1987, Endrödy-Younga (#2422) (3 TMSA) ; Uitsuk , window trap, 25° 15' S, 30° 33' E, 15 xii 1986, Endrödy-Younga (#2390) (1 TMSA) ; White River, White River hinter Staumauer , Quelle , 25° 20' S, 31° 1' E, 31 v 2001, A. Skale (4 NMW) ; 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) (4 BMNH) .

Differential diagnosis. Very similar in size, color and dorsal habitus to H. cooperi ( Figs. 2 , 42 ); differing therefrom by having the metaventral plaques carinate lines instead of ovals (ratios 1.5/0.3/6/5 vs. 2/1/1/5). The aedeagi of the two species, however, differ markedly ( Figs. 4 , 44 ). The other species with carinate metaventral plaques, H. habitiva , differs markedly from H. humanica in both habitus and aedeagus. The aedeagus of H. humanica does not suggest placement in any of the groups.

Description. Size: holotype (length/width, mm): body (length to elytral apices) 1.40/0.59; head 0.23/0.35; pronotum 0.35/0.47, PA 0.38, PB 0.42; elytra 0.88/0.59. Dorsum of head dark brown to piceous; pronotum light brown around dark brown macula; elytra brown; legs light brown to testaceous; maxillary palpi testaceous, except distal ½ of last palpomere slightly darker. Mentum moderately densely finely punctulate, interstices shining; postmentum punctate, slightly depressed on each side. Genae raised, shining, without posterior ridge.

Frons punctures ca. 1xef, 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.

Pronotum laterally very 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 almost obsolete; PF3 shallow; PF4 very shallow or obsolete.

Elytra weakly arcuate; 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 deep angle with one another.

Ratios of P2 width and plaque shape (P2/w/l/s) ca. 1.5/0.3/6/5. P1 laminate; median carina sinuate in profile. P2 l/w ca. 4/1, sides slightly converging toward blunt apex, apex raised slightly above mesoventral intercoxal process. Plaques carinate lines, straight, slightly converging toward one another anteriorly, located at sides of moderately deep median depression. Metaventrite with low midlongitudinal carina between intercoxal process and median depression. AIS width at slightly arcuate posterior margin ca. 3x P2. All tibiae slender, straight. Abdominal apex very slightly asymmetrical; last tergite with minute apicomedian notch. Female (microslide mount, n=1): last tergite moderately broadly rounded, with minute apicomedian notch, ca. 28 hooked setae in single row, semicontiguous; 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 shape of the aedeagus in lateral view.

Distribution. Currently known only from Mpumalanga Province and KwaZulu-Natal Province, South Africa ( Fig. 72 ).

Figures

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

FIGURE 42. Hydraena humanica, holotype, dorsal and lateral habitus.

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

FIGURES 44–45. Aedeagi of holotypes.

FIGURES 71–74. Geographical distributions of Hydraena species.