Discozantaena tibiovela, 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 : 17-18

Discozantaena tibiovela new species

( Figures 9 , 20 , 32 )

Type Material. Holotype (male): South Africa: Natal, 75km WSW Estcourt, Cathedral Peaks For. Sta, 2000m, pine plantation rotted Boletus litter, berlese 14, 20 December 1979, S. & J. Peck; deposited in the TMSA. Paratypes (19): Same data as holotype, (2 MCZ). Helpmekaar R., Pietersbg. Dist., in mould, ix.1960, N. Leleup, (Z.A. 19) — (6 TMSA). N. Transvaal, L. Trichardt, Hanglip, 23.00°S, 29.54°E, standing dead tree, 22 April 1976, Endrödy­Younga (#1142) — (10 TMSA). Natal Middld, Karkloof for. 1300m, 29.18°S, 30.13°E, sifted forest litter, 5 December 1989, Endrödy & Klimaszew (E­Y #2745) — (1 TMSA). Representative specimens to be deposited in MCZ.

Diagnosis. Recognized by the shining, almost non­granulate pronotal reliefs, the straight lateral margin of the pronotum, and the very explanate elytral margins that are not emarginate before the apices ( Fig. 9 ).

Description. Size (length/width, mm) holotype: body (length to elytral apices) 1.75/ 0.91, head 0.28/0.51, pronotum 0.42/0.78, elytra 1.13/0.91. Dorsum dark brown, explanate margin of pronotum and elytra lighter; venter brown. Frons flattened but feebly gibbous between oblique foveae, disc with moderately dense granules, moderately shining; granules sparser laterally. Clypeus very transverse, anterior angles very widely rounded, anterior margin emarginate; shining, very finely and very sparsely granulate. Labrum moderately shining, pubescence very short and very sparse; apicomedian emargination slightly reflexed.

Pronotum very transverse; anterior margin straight, median 1/2 with narrow hyaline border; anterior angles sharply rounded; sides nearly straight; posterior margin arcuate except emarginate near posterior angles. Sides minutely denticulate. Disc roundly elevated between anterior and posterior broadly U­shaped transverse impressions; granules dense in impressions, much finer and sparser on relief separating U­shaped impressions and relief around posterior U­shaped impression; lateral area with rather large, moderately convex, non­granulate area.

Elytra with anterior angles sharply rounded, sides weakly arcuate to middle, then markedly attenuate to very narrowly truncate apices; external to tenth series broadly explanate almost to apex, moderately shining; sides minutely serrate, pubescence very fine and short. 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, setae not quite overlapping; each setal base with minute granule. Intervals impunctate, shining in clean specimens, flat, slightly wider than serial punctures. Sutural margin raised slightly in posterior 1/2. Humeri obsolete.

Wings brachypterous. Metasternum with low midlongitudinal carina in anterior 1/4, shallow fovea in posterior 3/4. Thoracic sterna and abdominal ventrites 1–4 and basally ventrite 5 clothed with sparse short pubescence.

Aedeagus total length 0.55 mm; mainpiece length 0.45 mm; mainpiece thick and widened area diagnostically shaped; flagellum not forming corkscrew spiral; basal 3/4 stiff, apical 1/4 weakly sclerotized and shape therefore varying depending on preparation; collar in front of flagellum only, not wrapping around as in some species ( Fig. 20 ).

Etymology. Named in reference to the protected position of the tibia, beneath the explanate margin of the elytra.

Distribution. Presently known from Natal and Transvaal Provinces ( Fig. 32 ).

Notes. This is a flightless species, the wings being about 1/2 the length of the elytra. The pronotum of the holotype ( Fig. 9 ) has the sides slightly emarginate in the anterior 0.5; most other specimens have straight sides.

Figures

FIGURE 9. Discozantaena tibiovela holotype. Dorsal and lateral habitus.

FIGURE 20. Discozantaena tibiovela. Aedeagus of holotype.

FIGURES 32 – 34. Discozantaena distribution maps. — 32. D. tibiovela. — 33. D. leleupi. — 34. D. sepiola.