Parhydraena sebastiani, Perkins, 2009

Perkins, Philip D., 2009, Revisions of the genera Parhydraena Orchymont, Protozantaena Perkins, Decarthrocerus Orchymont, and Parhydraenopsis nomen novum, aquatic and humicolous beetles from Africa and Madagascar, and comparative morphology of the tribe Parhydraenini (Coleoptera: Hydraenidae), Zootaxa 2038, pp. 1-119 : 31-32

Parhydraena sebastiani new species

( Figs. 58, 76, 97)

Type material. Holotype (male): South Africa: KwaZulu-Natal Province, Cathedral Peak , air plankton, 28° 57' S, 29° 12' E, 18.iii.1976, Endrödy-Younga (#1100). Deposited in the TMSA . Paratype: Lesotho: Quthing, elev. 1646 m, 30° 23' S, 27° 43' E, 15.iii.1951, Brinck & Rudebeck (1 LUM) .

Differential diagnosis. Recognized by the subserial or non-serial elytral punctures, the comparatively short maxillary palpi (palpus length/head width ca. 0.64 mm), and the comparatively large body size (length ca. 2.17 mm) ( Fig. 58). The pronotal relief is M-shaped and very finely punctate, markedly contrasting with the rugose surrounding area. Like the habitus, the aedeagus stands apart from other members of the genus ( Fig. 76).

Description. Size (length/width, mm) holotype: body (length to elytral apices) 2.17/0.92; head 0.38/0.55; pronotum 0.48/0.76, PA 0.59, PB 0.64; elytra 1.36/0.92. Head piceous, pronotum dark brown laterally, very gradually changing to piceous on disc, elytra dark brown, legs and maxillary palpi brown, distal mere slightly darker than remainder of palpus.

Head with eyes moderately large, in dorsal aspect 8 small, convex facets in longest series. Ocelli distinct round small shining, each located at base of moderately deep oblique interocular fovea. Frons on disc distinctly finely punctate, ca. 0.5–1xef, interstices smooth, strongly shining, 1–4xpd; area between interocular foveae and eye flat, microreticulate, punctate, dull. Clypeus dull, effacedly microreticulate and indistinctly, very finely punctate, punctures smaller than those of frons disc. Labrum effacedly microreticulate, weakly shining, apicomedially with small V-shaped notch; laterally fringed with short arcuate setae. Each dorsal puncture of head with short, indistinct, recumbent seta. Maxillary palpi short, combined lengths of meres much less than width of head (ratio ca. 25/39); ratios of meres 2–4 ca. 9/5/11. Mentum and submentum sparsely finely punctulate, interstices shining. Metasternum with very shallow median elongate oval impression in basal 1/2, midlongitudinal carina posterior to mesoventral intercoxal process very short, well separated from oval impression.

Pronotum with distinct M-shape on disc; anterior margin weakly arcuate, median 1/3 with extremely narrow hyaline border. Anterior angles obtuse, widely rounded. Sides rounded, widest at middle, behind middle gradually attenuate, straight or nearly so. Posterior angle obtusangulate. Disc distinctly raised between anterior and post impressions, posterior impression deeper than anterior, broadly U-shaped, with anterior margin more abrupt than posterior margin; punctation much larger and much denser in impressions than on disc, some punctures confluent; punctures on discal relief very fine, 0.5xef or less, and very sparse, interstices strongly shining; shallow wide impression at each posterior angle. Sculpture laterally subrugose, dull, punctures entirely or almost entirely confluent, longitudinally oriented ridges very prominent.

Elytra elongate-ovate, sides arcuate, margins distinct from shoulder for 2/3 of length. Ten-seriate punctate, but series 3–8 more or less randomly arranged, punctures non-granulate, each with small seta; only first series striate-impressed, in distal 1/2; punctures ca. 2xef, longitudinally separated 1xpd, becoming finer and shallower on apical declivity. Interval width 2–3xpd, weakly shining, each with unilinear row of widely spaced, minute, non-granulate punctures, each with minute recumbent seta.

Metaventrite and abdominal ventrites 1–4 hydrofuge pubescent. Ventrite 5 hydrofuge pubescent in basal 1/2, posterior 1/2 effacedly microreticulate, shining, very sparsely pubescent. Ventrite 6 weakly, effacedly microreticulate, shining, with transverse band of sparse setae across posterior 1/2. Male: last ventrite asymmetrical, apex lobiform and setose; last tergite with tuft of setae on each side of apicomedian notch into which fits lobe of last ventrite. Female unknown.

Legs moderately long and slender, combined lengths of metatibia and metatarsus greater than width of head (ratio ca. 52/39), ratio of lengths of metatibia/metatarsus ca. 33/19. Basal 3 pro- and mesotarsomeres, in male, with pad of suction setae.

Wings fully developed in holotype and paratype.

Aedeagus length ca. 0.39 mm; main-piece, in ventral view, with small, pointed lobe on left side; distal piece very large, with large sinuate process visible in right lateral view; gonopore bearing process comparatively thick ( Fig. 76).

Etymology. Named in honor of Sebastian Endrödy-Younga.

Distribution. Currently known from two moderately widely separated localities, one each in KwaZulu- Natal Province (very near the northern Lesotho border) and one in southernmost Lesotho ( Fig. 97).