Discozantaena galea, 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 : 13-14

Discozantaena galea new species

( Figures 6 , 17 , 29 )

Type Material. Holotype (male): Cape, Swartberg Pass, 33° 54' S, 22° 01' E, 1770m, sifted, 1.viii.1979, Breytenbach, E.­ Y. (#1643); deposited in the TMSA. Paratypes: Same data as holotype — (2 TMSA).

Diagnosis. Recognized by the very wide explanate margins of the elytra, the straight lateral margins of the pronotum, and the granulate frons disc ( Fig. 6 ).

Description. Size (length/width, mm) holotype: body (length to elytral apices) 2.05/ 1.08, head 0.31/0.57, pronotum 0.49/0.93, elytra 1.25/1.08. Dorsum generally dark brown, head and disc of pronotum piceous, explanate margins of pronotum and elytra brown; venter brown, elytral epipleurae and pronotal hypomeron lighter. Frons feebly gibbous between oblique foveae, disc densely granulate, granules becoming sparser laterally; decumbent setae short, directed posteriad on disc, directed mediad near eyes. Clypeus transverse, anteriorly weakly emarginate, anterior angles rounded; finely sparsely granulate across posterior 0.75, shining. Labrum very finely sparsely setose, shining; sinuation apicomedian emargination very slightly reflexed, if at all.

Pronotum very transverse; anterior margin straight except weakly emarginate over median 1/2 with narrow hyaline border; anterior angles sharply rounded; sides straight until markedly arcuate before small emargination in front acute, tooth­like posterior angles; posterior margin arcuate except emarginate near posterior angles. Sides minutely denticulate. Disc 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 round granule; granules rather uniformly dense in impressions, sparser on relief; interstices strongly shining. Lateral explanate area strongly shining, granules much sparser than in impressions.

Elytra with anterior angles sharply rounded, sides weakly arcuate to middle, then markedly attenuate to very narrowly truncate apices; lateral to tenth series very broadly explanate almost to apex, 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 almost 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 over posterior 0.75. Humeri obsolete.

Metanotum with wings about 1/2 the length of the elytra. Metasternum with midlongitudinal carina over anterior 1/2 and narrow midlongitudinal fovea over posterior 1/2. Thoracic sterna and abdominal ventrite 1 completely and ventrites 2–4 laterally with short pubescence.

Aedeagus total length 1.06 mm; mainpiece length 0.68 mm; aedeagus large compared to other species; mainpiece distal widened area and large collar are diagnostically shaped; flagellum forms a rather tight corkscrew spiral, apical 1/5 weakly sclerotized and shape can therefore vary depending on preparation ( Fig. 17 ).

Etymology. Named in reference to the helmet­like shape of the elytra.

Distribution. Presently known only from the type locality in the Swartberg mountains of the southern Cape Province ( Fig. 29 ).

Notes. This is a flightless species.

Figures

FIGURE 6. Discozantaena galea holotype. Dorsal and lateral habitus.

FIGURE 17. Discozantaena galea. Aedeagus of holotype.

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