Limnebius convexus, Perkins, Philip D., 2015

Perkins, Philip D., 2015, Taxonomy of the water beetle genus Limnebius Leach in southern Africa (Coleoptera: Hydraenidae), Zootaxa 3948 (1), pp. 41-59 : 45

Limnebius convexus , new species

Figs. 3 (habitus), 13 (aedeagus), 27 (map)

Type material. Holotype (male): South Africa: Western Cape Province, Little Karroo, Raubenheimer Dam, shore washing, 33° 25' S, 22° 19' E, 21 x 1993, Endrödy-Younga (#2888) ( TMSA). A total of 1,001 additional specimens; specimens are paratypes unless otherwise noted: South Africa: Eastern Cape Province, Chapman’s Bay, little pond, 34° 1' S, 18° 20' E, 8 vii 1903, Vanhoffen, Ernst (2 ZMHB); nr. Humansdorp, Gamtoos River, small shallow pool cut in reeds, 34° 0' S, 24° 48' E, 20 iii 1954, J. Balfour-Browne (3 BMNH); Uitenhage District, Van Staaden’s Pass, in gravel at edge of fast stream, 33° 54' S, 25° 12' E, 21 iii 1954, J. Balfour-Browne (84) (20 BMNH); Mpumalanga Province, E. Transvaal, Blyderiver Canyon, shore washing, 24° 35' S, 30° 49' E, 2 v 1981, Endrödy-Younga (#1765) (1 TMSA); Western Cape Province, Cape Flats, Varden Vlei, 2 mi. E. Ottery, 34° 6' S, 18° 30' E, 2 ii 1951, Brinck & Rudebeck ( SSAE 163) (9 LUM); Elandsdrift, shore washing, 34° 39' S, 19° 53' E, 24 ii 1981, Endrödy-Younga (#1747) (20 TMSA); Hex River Mts., 7 km SW Ceres, Breede River, rockpools, elev. 400 m, 33° 23' S, 19° 19' E, 26 ii 1997, Hess (1 NMW); Little Karroo, Raubenheimer Dam, shore washing, 33° 25' S, 22° 19' E, 21 x 1993, Endrödy-Younga (#2888) (22 TMSA); Little Karroo, Raubenheimer Dam, shore washing, after debris removed, 33° 25' S, 22° 19' E, 21 x 1993, Endrödy-Younga (#2889) (146 TMSA); Little Karroo, Raubenheimer Dam, water collection, 33° 25' S, 22° 19' E, 21 x 1993, Endrödy-Younga (#2886) (17 TMSA); Nuweberg, 10km NE, water plankton, 34° 3' S, 19° 15' E, 13 xi 1973, Endrödy-Younga (#239) (13 TMSA); Nuweberg For. Sta., grassnetting nr. dam, 34° 3' S, 19° 4' E, 13 xi 1973, Endrödy-Younga (#242) (2 TMSA); S. W. Cape, Nuweberg, 10km NE, shore washing, 34° 3' S, 19° 6' E, 13 xi 1973, Endrödy-Younga (#240) (292 paratypes, 436 non-types TMSA); SW Cape, Verlorevlei Farm, shore washing, 32° 19' S, 18° 22' E, 28 viii 1981, Endrödy- Younga (#1857) (12 TMSA); Temp. pool beside R324 road 12 km S. of Barrydale, below Tradouw Pass, 33° 59' S, 20° 42' E, 19 ix 2009, D. T. Bilton (1 DTBC); W. Cape, Hawequas, shore washing, 33° 34' S, 19° 8' E, 10 xi 1973, Endrödy-Younga (#226) (2 TMSA).

Differential diagnosis. Habitus as illustrated ( Fig. 3 ); a small species with body form distinctly drop-shaped, apically distinctly acuminate, pronotal disc non-microreticulate, elytra weakly microreticulate. The aedeagus ( Fig. 13) is arcuate near the midlength, more strongly so in ventral than in lateral view; the distal part, in ventral view, is widened on the right side, forming an axe or hatchet shape; the distal part has setae as illustrated, including a pair of long setae visible in lateral view; the capsule begins near the base and extends to the apex. The pronotal disc of the holotype has a shallow impression on each side, near the base ( Fig. 3 ); these impressions are not present on most specimens.

Description. Size: holotype (length/width, mm): body (length to elytral apices) 1.10/0.61; pronotum 0.28/ 0.60; elytra 0.67/0.61; approximate height, lateral view 0.35. Dorsum piceous, elytral apices sometimes slightly paler. Body form distinctly drop-shaped, apically distinctly acuminate, side margin indented slightly where pronotum joins elytra. Pronotum with disc strongly shining, non-microreticulate, very sparsely very finely punctulate, some punctures with very short and fine, nearly imperceptible adpressed seta; areas posterior to eye (side view) and near lateral margin with few distinctly larger punctures, each puncture with adpressed seta, longer than setae on disc. Elytra weakly microreticulate, with punctures and setae similar to those on pronotum. Males with first three pro- and mesotarsal segments slightly enlarged, with adhesive setae. Labroclypeal suture bisinuate in frontal view in both sexes. Labrum of male with anterior margin not thickened, lateral area on each side weakly excavate; labrum of female simple, slightly more deeply apicomedially emarginate than male. Elytral apices slightly more widely rounded in males than in females.

Etymology. Named in reference to the convex shape.

Distribution. Currently known from the Eastern and Western Cape Provinces of South Africa, plus one disjunct locality in Mpumalanga Province ( Fig. 27).

Figures

FIGURES 1 – 4. Dorsal and lateral habitus views of holotypes.