Pneuminion nanum, 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 : 12-13

Pneuminion nanum new species

( Figures 10 , 19 , 28 )

Type Material. Holotype (male): South Africa: Cape Mt., Helderfont. S, 1220m, 33.56S ­ 20.52E, sifted, alpine marsh, 10.iii.1979, Endrödy­Younga (#1566); deposited in the TMSA. Paratypes: Same data as holotype, (3 TMSA, 1 MCZ).

Diagnosis. Recognized by the small size, ca. 1.30 mm long (smallest known species in the genus), the subsulcate elytra with whitish setae forming uninterrupted unilinear row on intervals and interrupted unilinear row on series, and the small heart­shaped punctures on the frons disc and pronotal reliefs ( Fig. 10 ).

Description. Size (mm x 100; length/width): body (length to elytral apices) 130/57, head 22/39, pronotum 33/52, elytra 81/57.

Dorsum dark brown to black, legs and maxillary palpi brown; dorsal setae moderately conspicuous, whitish. Labrum and clypeus dull, micropunctulate. Frons disc punctate, interpunctal surface smooth, shining, punctures separated by ca. 1.5xpd. Fovea in front of each ocellus large, ca. 5x ocellus, deep, micropunctulate.

Pronotum weakly shining on disc, dull laterally, impressions deep; punctures on reliefs small, separated by ca. 1xpd, each with short whitish, granule­based seta; 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. Pronotal postocular emarginations deeper and less symmetrical in females than males.

Elytra subsulcate, intervals slightly raised, each with a unilinear row of slightly overlapping setae; serial punctures moderately large, 2– 3 x than those of pronotal reliefs, each with a short seta, setae not overlapping and not forming uninterrupted line like setae of intervals; each seta granule­based; explanate margin narrow in both sexes

Aedeagus: main­piece length 35, total length 70; duct very long, very slender over distal 3/4; paramere setae comparatively sparse; main­piece with ridge/groove to support duct ( Fig. 19 ).

Etymology. Named in reference to the small size.

Figures

FIGURE 10. Pneuminion nanum holotype. Dorsal and lateral habitus.

FIGURE 19. Pneuminion nanum. Aedeagus of holotype.

FIGURES 26 – 28. Pneuminion distribution maps. — 26. P. balfourbrownei. — 27. P. impressum. — 28. P. nanum.