Discozantaena ovata, Perkins, Philip D., 2005

Perkins, Philip D., 2005, A revision of the South African endemic humicolous beetle genus Discozantaena Perkins and Balfour­Browne (Coleoptera: Hydraenidae), Zootaxa 915, pp. 1-48 : 16-17

Discozantaena ovata new species

( Figures 8 , 19 , 31 )

Type Material. Holotype (male): SW Cape, Groot Toren farm, river shore and stones, 31° 20' S, 19° 44' E, 15 September 1994, Endrödy­Younga (#3004); deposited in the TMSA. Paratypes (14): Same data as holotype, (9 TMSA). Cape Prov., Cape Farm Ezelsfontein, shore washing, 30° 24' S, 18° 5' E, 30 October 1977, Endrödy­Younga (#1407) — (1 TMSA); No. Cape, Richtersveld, Oemsberg, shore washing in shade, 28° 27' S, 17° 10' E, 23 September 1991, Endrödy­Younga (#2796) — (1 TMSA); Natal Prov., Howick, Umgeni River, Lions River Dist., humus, ZA 77, 29° 48' S, 31° 3' E, 1–30 October 1961, N. Leleup — (3 TMSA). Representative specimens to be deposited in MCZ.

Diagnosis. Recognized by the wide body form, the straight anterior margin of the clypeus, and the comparatively large size (ca. 2.25 mm long), largest known species in the genus ( Fig. 8 ).

Description. Size (length/width, mm) holotype: body (length to elytral apices) 2.25/ 1.16, head 0.37/0.62, pronotum 0.51/0.97, elytra 1.38/1.16. Dorsum brown, head and disc of pronotum darker; venter brown, elytral epipleurae and pronotal hypomeron lighter. Frons flattened but feebly gibbous between oblique foveae, disc moderately shining; decumbent pubescence short, small granule at base of each seta, on disc setae sparse, directed posteriad, near eyes setae denser, directed mediad. Clypeus transverse, anterior margin straight, anterior angles rounded; shining, granules almost imperceptible. Labrum punctate, weakly shining; apicomedian emargination slightly reflexed.

Pronotum very transverse; anterior margin straight, median 1/2 with narrow hyaline border; anterior angles widely rounded; sides markedly arcuate except weakly emarginate before acute, tooth­like posterior angles; posterior margin arcuate except emarginate near posterior angles. Sides minutely denticulate. Disc quite strongly roundly elevated between anterior and posterior broadly U­shaped transverse impressions, clothed with moderately dense, short decumbent golden setae, socket of each seta very indistinct but anterior rim raised to form distinct oblong or 8­shaped granule; granules rather uniformly dense on disc, slightly sparser on posterior slope of relief, much sparser laterally; interstices strongly shining. Lateral depressions shining between granules.

Elytra with anterior angles sharply rounded, sides arcuate; lateral to tenth series broadly explanate almost to apex, moderately shining; sides minutely serrate, pubescence dense, short and overlapping. Ten seriate punctate, but two additional series on explanate margin, series not striate impressed, punctures transversely oval, those near base contiguous longitudinally, posteriorly becoming little more separated and slightly smaller, each with distinct short decumbent seta, serial setae overlapping, each setal base with minute granule. Intervals impunctate, shining, flat, slightly wider than serial punctures. Sutural margin raised slightly in posterior 1/2.

Metasternum with midlongitudinal furrow over posterior 0.75. Thoracic sterna and abdominal ventrites 1–4 entirely and 5 basally clothed with sparse short pubescence, cuticle micropunctulate.

Aedeagus total length 0.73 mm; mainpiece length 0.45 mm; mainpiece distal widened area and small collar diagnostically shaped; flagellum long, thick, stiff and only slightly curved, apical 1/6 weakly sclerotized and shape can therefore vary depending on preparation.

Etymology. Named in reference to the widely ovate body shape.

Distribution. Presently known from western Cape Province and one record in eastern Natal Province ( Fig. 31 ).

Notes. The specimens from Natal Province (one male, two females) are smaller than those from the Cape Province; however, the aedeagus of this male differs only very slightly, in curvature of the mainpiece, from the aedeagus of the holotype. There is a very wide distribution gap between this locality and those in the western Cape; the Natal specimens might be mislabeled.

Figures

FIGURE 8. Discozantaena ovata holotype. Dorsal and lateral habitus.

FIGURE 19. Discozantaena ovata. Aedeagus of holotype (detail in two views).

FIGURES 29 – 31. Discozantaena distribution maps. — 29. D. galea. — 30. D. karroo. — 31. D. ovata.