Pneuminion tubum, Perkins, Philip D., 2004

Perkins, Philip D., 2004, A revision of the South African endemic water beetle genus Pneuminion Perkins (Coleoptera: Hydraenidae), Zootaxa 538, pp. 1-38 : 9

Pneuminion tubum new species

( Figures 5 , 15, 25 )

Type Material. Holotype (male): South Africa: S. W. Cape Mts., Hawequas SE, 1100m, 33.41S ­ 19.06E, water coll. in rapid, 5.xi.1973, Endrödy­Younga (#203); deposited in the TMSA.

Diagnosis. A relatively smooth species, especially on the head and elytra. Recognized also by the transversely convex form, the sulciform impressions of the frons, the small punctures on the pronotal reliefs appearing paired, and the relatively smooth, nongranulate elytra ( Fig. 5 ).

Description. Size (mm x 100; length/width): body (length to elytral apices) 152/67, head 30/44, pronotum 37/56, elytra 93/67.

Dorsum dark brown to piceus on head and pronotum, elytra, legs and maxillary palpi brown; dorsal setae conspicuous, very slender, testaceous. Labrum and clypeus weakly shining, finely sparsely punctate. Frons disc punctate, interpunctal surface smooth, shining, punctures separated by ca. 1–2.5xpd. Fovea in front of each ocellus narrow, oblique groove, about as wide as ocellus.

Pronotum dull, densely moderately finely punctate, punctures on reliefs each with short, granule­based seta, granule dividing puncture in half, punctures therefore appearing paired, most oriented transversely or subtransversely, some punctures near base only partially divided by granule, therefore heart­shaped; oblique anterior fovea on each side shallowly connecting to midlongitudinal fovea; posterior U­shaped fovea well­developed; setae at lateral margin flat on cuticle in dry specimens.

Elytra with setae of series and interseries almost equally developed, resulting in narrowly separated unilinear rows of very fine setae, about 18 on each elytron; setae of intervals slightly more apparent than those of series; granule at base of each seta very small, if perceptible; serial punctures separated by about puncture diameter, slightly narrower than intervals, cuticle moderately shining at side of punctures; intervals very slightly raised; explanate margin very narrow.

Aedeagus: main­piece length 43, total length 51; duct sharply S­shaped, gradually thickened from about midlength to apex, tip expanded; main­piece blade­shaped, lacking ridge/groove; paramere setae comparatively sparse, clustered distally on right paramere; right paramere attaining level of apex of main­piece ( Fig. 15).

Etymology. Named in reference to the tube­like duct of the aedeagus.

Figures

FIGURE 5. Pneuminion tubum holotype. Dorsal and lateral habitus.

FIGURES 23 – 25. Pneuminion distribution maps. — 23. P. velamen. — 24. P. semisulcatum. — 25. P. t u b u m.