Pneuminion fontinalis, Bilton, David T & Perkins, Philip D, 2012

Bilton, David T & Perkins, Philip D, 2012, Two new species of Parhydraenini from South Africa (Coleoptera: Hydraenidae), Zootaxa 3342, pp. 51-59 : 54-57

Pneuminion fontinalis , new species

( Figs. 3 & 4)

Type Material. Holotype (male): 26/ix/2008, South Africa, Western Cape Province, madicolous seepage beside R46 road in Mitchell’s Pass, ca. 5 km SW of Ceres, 33° 24’ 09.24” S, 19° 17’ 08.96” E, 386 m, D.T. Bilton leg. ( SAM). Paratypes (7): 27/ix/2009, South Africa, Western Cape Province, Mitchell’s Pass on R46 ca. 5 km SW of Ceres, wet rock faces, D.T. Bilton leg. (1 SAM, 1 TMSA, 1 MCZ, 3 CBP).

Differential Diagnosis. Members of this species will key to P. balfourbrownei in Perkins (2004). P. fontinalis n. sp. is slightly smaller and slightly narrower, and has the elytra slightly shorter relative to the length of the pronotum. The two species differ distinctly in the pronotal sculpture: the foveae are very shallow in P. fontinalis n. sp. ( Fig. 3), whereas the foveae are deep in P. balfourbrownei . The aedeagi of the two species differ distinctly in the shapes of both the flagellum and the mainpiece ( Fig. 4; Fig. 14 in Perkins 2004).

Description. Size: (length/width, mm) holotype: body (length to elytral apices) 1.53/ 0.65, head 0.29/0.45, pronotum 0.37/0.56, elytra 0.90/0.65. Colour: Dorsum black, hind angles of pronotum dark piceous; legs and maxillary palpi dark brown; venter black. Head: Labrum and clypeus weakly shining, with shallow microreticulation which is more strongly developed towards lateral margins. Surface finely punctate; punctures sparse on centre of clypeus, where they are spaced approximately two puncture-widths apart; denser towards lateral margins. Frons sparsely punctate, shining and weakly microreticulate. Punctures denser, and microreticulation more strongly developed towards margins of eyes. Punctures on frons deeper than on clypeus, and separated by ca. 1–1.5 puncture diameters. Fovea in front of ocelli large, approximately 4X size of ocellus; densely punctate and strongly microreticulate, with abrupt median margin; more open towards eyes, and extending as a shallow, heavily punctate and microreticulate area between ocelli and eyes, and posteriorly to the hind margin of the head. Dorsal hyaline setae conspicuous; slender and transparent, at least 4–5 puncture diameters in length. Pronotum: Surface shining, with traces of obsolete microreticulation; punctures in reliefs small and with a granule at the front margins, bearing a hyaline seta; granule often projecting posteriorly, giving punctures the appearance of being paired, or horseshoe-shaped. Midlongitudinal fovea weak; anterior and posterior fovea both well-marked and shallowly extending

towards midline, deeper towards lateral margins where punctures are much larger and open posteriolaterally. Punctures towards lateral margins often confluent, appearing as lowered, heavily microreticulate areas. Pronotal postocular impression shallow. Setae on pronotal reliefs long and transparent, adpressed against the surface, and orientated antero-posteriorly, reaching back at least to the anterior margin of next puncture, and at least 4–5 puncture diameters in length. Wings full-length. Elytra: Shining and lacking microreticulation. Setae of series and intervals equally developed, resulting in about 20 discrete linear rows on each elytron. Setae granule-based, transparent, whitish and closely adpressed to elytral surface; relatively long, reaching back to insertion point of next seta in each row. Serial punctures moderately large, shallow and slightly narrower than intervals. Elytra with narrow explanate margin. Very weak saddle in middle of elytra ca. 1/3 from base. Aedeagus: total length 0.61 mm; mainpiece length 0.44 mm. Duct weakly arcuate, approximately 2X length of mainpiece, thick at base, but slender over most of length, particularly apical third, with abruptly expanded weakly sclerotized apex (only visible with transmitted light—duct appearing finely pointed with incident light at lower magnification). Mainpiece evenly curved, with a bluntly pointed, deflexed tip; apical third grooved and laterally arched to guide duct. Parameres slender, approximately same length as main piece, with long setae on apical sections. Female: Pronotal postocular impression deeper and less symmetrical than in males. Explanate margin of elytra wider than in males, and elytral sides more strongly rounded. Variation: The strength of the pronotal impressions and elytral saddle vary slightly between the paratypes.

Etymology: Named in reference to the habitat—damp areas beside permanent films of water flowing over rock.

Distribution and Ecology: So far only reported from the type locality, a hygropetric seepage in Mitchell’s Pass near Ceres in the Western Cape Province ( Fig. 6 ). At Mitchell’s Pass Pneuminion fontinalis n. sp. has been found on damp rock with algal biofilms and fine clay beside permanent and semi-permanent trickles of water, formed where springs flow over exposed rock in a road cutting. The species appears to be relatively rare; the eight specimens of the type series being found in approximately 4 hours of sampling over two visits. The habitat was searched by eye, and beetles obtained with a finger or a small length of grass stem, used to winkle them out of crevices. Specimens were found on lower parts of the rock face, mostly ca. 0.5 m above ground level, in areas with fine biofilms, and surrounding grass and fern layers, providing partial shade. Most beetles were visible on the open rock face, but some were found inhabiting the overhangs of small crevices. The seepage habitats at Mitchell’s Pass host a rich hygropetric fauna, this being one of the original localities in which the recently described relictual water beetle family Aspidytidae was found ( Ribera, et al., 2002; Alarie & Bilton, 2007). Larvae and adults of Aspidytes niobe Ribera, Beutel, Balke & Vogler, 2002 occur in wetter areas of seepage than Pneuminion fontinalis n. sp., but the new species is microsympatric with Canthyporus nebulosus Omer-Cooper, 1965 ; Africophilus jansei Omer- Cooper & Omer-Cooper, 1957, Anacaena glabriventris Komarek, 2004 , A. reducta Komarek, 2004 and a range of SW Cape endemic Hydraenidae , including the relatively widespread congener Pneuminion velamen Perkins, 1997 , Coelometopon blinkwater Perkins, 2005 , Oomtelecopon sebastiani Perkins, 2005 , and a further species of Oomtelecopon still to be described.

Figures

FIGURE 6. Type Locality of Pneuminion fontinalis n. sp. Hygropetric habitat beside R 46 at Mitchell’s Pass, ca. 5 km SW of Ceres, Western Cape Province, South Africa. Arrow indicates area in which the Holotype was collected. Photo D. T. Bilton.