Pneuminion impressum, 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 : 13-14

Pneuminion impressum new species

( Figures 11 , 20 , 27 )

Type Material. Holotype (male): South Africa: W. Cape, Dwarsberge, 34.02S ­ 19.01E, sifted moss, 15.XI.1973, Endrödy­Younga (#254); deposited in the TMSA. Paratype: Same data as holotype, (1 female TMSA).

Diagnosis. A very distinct species, recognized by the deeply impressed and wide pronotal foveae, the rugulose head and pronotum, and the highly modified elytra with a saddle and each elytron with five unilinear rows of setae ( Fig. 11 ). The basic aedeagal form is unique in the genus.

Description. Size (mm x 100; length/width): body (length to elytral apices) 155/70, head 30/44, pronotum 41/59, elytra 100/70.

Dorsum dark brown to brown, legs and maxillary palpi brown to testaceous; dorsal setae very conspicuous on head and pronotum, whitish. Dorsum of head and pronotum rugulose, dull. Frons with fovea in front of ocellus deep, ca. 5x ocellus diameter.

Pronotal postocular emarginations deeper and less symmetrical in females than males. Pronotum dull, impressions very deep and large, midlongitudinal impression as wide as eye, reliefs quite convex; setae short, denser and more slender on reliefs, becoming sparser and wider laterally.

Elytra with shallow transverse depression (“saddle”) at basal 0.3. Each elytron with five unilinear rows of overlapping, whitish setae, rows present on sutural interval and intervals 2, 4, 6, and 7, rows on intervals 2 and 4 interrupted over a short distance at saddle; interval 1 with short row of setae between base and saddle, and interval 5 with short row at base, otherwise odd­numbered intervals smooth, lacking setae; serial punctures moderately large, larger than smooth intervals separating them, each with a short indistinct seta, setae not overlapping and not forming lines; granules at bases of setae very small, if perceptible; sutural margin raised between saddle and apices; explanate margin very narrow.

Aedeagus: main­piece length 36, total length 45; parameres comparatively short, setae sparse, grouped at apex; duct joined with main­piece over basal 2/3, apical 2/3 thicker ( Fig. 20 ).

Etymology. Named in reference to the deeply impressed pronotal and elytral sculpture.

Figures

FIGURE 11. Pneuminion impressum holotype. Dorsal and lateral habitus.

FIGURE 20. Pneuminion impressum. Aedeagus of holotype.

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