Discozantaena karroo, 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 : 15-16

Discozantaena karroo new species

( Figures 7 , 18 , 30 )

Type Material. Cape Province, Little Karroo , Raubenheimer Dam, sifted shore debris, 33° 25' S, 22° 19' E, 21 October 1993, Endrödy­Younga (#2887); deposited in the TMSA. Paratypes (18): Same data as holotype, (10 TMSA). Cape Prov., Cape, Langeberg, Ruiterbos For. St., sifted river debris, 33° 54' S, 22° 2' E, 4 November 1993, Endrödy­Younga (#2936) — (1 TMSA); Helderfontein, sifted, fynbos, elev. 1150 m, 33° 56' S, 20° 52' E, 8 March 1979, Endrödy­Younga (#1561) — (3 TMSA); Little Karroo , Kammanasieberge, water and shore, 33° 37' S, 22° 33' E, 21 November 1992, Endrödy­Younga (#2931) — (1 TMSA); Little Karroo , Raubenheimer Dam, shore washing, after debris removed, 33° 25' S, 22° 19' E, 21 October 1993, Endrödy­Younga (#2889) — (2 TMSA); Swartberge, Blesberg­E, grass netting, elev. 2000 m, 33° 25' S, 22° 41' E, 6 November 1978, Endrödy­ Younga (#1509) — (1 TMSA). Representative specimens to be deposited in AMG and MCZ.

Diagnosis. Recognized by the arcuate lateral margins of the pronotum, the nearly nongranulate frons disc, and the comparatively large size, length ca. 2.03 mm ( Fig. 7 ).

Description. Size (length/width, mm) holotype: body (length to elytral apices) 2.03/ 1.01, head 0.33/0.57, pronotum 0.46/0.83, elytra 1.25/1.01. Dorsum brown, head and disc of pronotum piceous; 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 very sparse, directed posteriad, near eyes setae denser, directed mediad. Clypeus transverse, anterior margin weakly emarginate, anterior angles rounded; sculptured and clothed as lateral areas of frons, but less densely. Labrum shining, very finely sparsely setose; margin of apicomedian emargination slightly reflexed.

Pronotum very transverse; anterior margin very weakly arcuate median 1/2 with narrow hyaline border; anterior angles sharply rounded; sides arcuate except emarginate before acute, tooth­like posterior angles; posterior margin arcuate except emarginate near posterior angles. Sides minutely denticulate. Disc strongly roundly elevated between anterior and posterior broadly U­shaped transverse impressions; granules dense in impressions, much finer and sparser on relief separating U­shaped impressions; lateral explanate area shining, with granules about as coarse as those in impressions, but much sparser.

Elytra with anterior angles sharply rounded, sides weakly arcuate to middle, then markedly attenuate to very narrowly truncate apices; 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 barely striate impressed, if at all, 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 narrow midlongitudinal impression. Thoracic sterna, abdominal ventrites 1–4 and basally 5 with sparse short pubescence.

Aedeagus total length 0.47; mainpiece length 0.33; mainpiece distal widened area and large collar diagnostically shaped; flagellum rather short and forms a loop in apical 1/2, apical 1/5 is weakly sclerotized and its shape can therefore vary depending on preparation ( Fig. 18 ).

Etymology. Named in reference to the geographical distribution.

Distribution. Presently known from the southern Cape Province ( Fig. 30 ).

Figures

FIGURE 7. Discozantaena karroo holotype. Dorsal and lateral habitus.

FIGURE 18. Discozantaena karroo. Aedeagus of holotype.

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