Coelometopon natalensis, Perkins, 2005

Perkins, Philip D., 2005, A revision of the African hygropetric genus Coelometopon Janssens, and description of Oomtelecopon new genus (Coleoptera: Hydraenidae), Zootaxa 949 (1), pp. 1-103 : 1-103

Coelometopon natalensis new species

(Figures 38, 39, 83)

Type Material. Holotype (male): South Africa: Natal Prov., Mpumalanga, Graskop , 28 km N, wet rockface, elev. 1400 m, 24° 43' S, 30° 51' E, 4 February 1997, Endrödy­Younga (3275); deposited in the TMSA . Paratypes: Same data (39 TMSA). Representative specimens deposited in AMG and MCZ .

Diagnosis. Similar in several dorsal features to C. brincki , but body smaller (ca. 2.41 mm vs. 2.56 mm) and with shorter elytra relative to the pronotal length (elytra/pronotum ca. 2.7 vs. 3.2) (Figs. 17, 38). The 7th and 8th intervals are normal in C. natalensis , whereas in C. brincki there is a distinct depression on the elytral 7th interval where the unilinear row of granules is interrupted, and below which the 8th interval is widened, thickened and multi­granulate. The relationship is also indicated by the aedeagi, which are similar but distinct (Figs. 18, 39).

Description. Size (length/width, mm x 100) holotype: body (length to elytral apices) 241/100, head 56/63, pronotum 56/85, elytra 152/100. Dorsum black. Maxillary palpus slightly shorter than width of anterior margin of clypeus, last three palpomeres subequal in length and maximum width. Mentum weakly produced apicomedially; depressed on each side of midline near base. Granules on frons and pronotum similar in size and density, those on clypeus slightly smaller and sparser. Pronotum with granules comparatively uniformly distributed, although absent from very narrow area in middle of median groove; sides emarginate in front of and behind roundly produced middle part, some marginal tubercles widely spaced in posterior emargination.

Elytral intervals: 2nd costate in three or four sections, first longest, second much shorter and third shorter again and decreasing in size posteriorly to form ill­defined fourth; 4th with four very short costae, one basal and one opposite each non­costate area of 2nd interval, raised unilinear row of granules continuing from fourth costa to elytral apices; 6th with two short costae, one each opposite costae two and three of 4th interval; odd numbered intervals each with unilinear row of granules; 7th raised slightly, except near basal 1/ 3.

Metasternum with large oval median depression, nearly attaining level of anterior carinae, sides gradually sloping. Male clypeus anterior angles slightly produced. Female last sternite apicomedially strongly emarginate, median depression shining, not rimmed posteriorly, continuing to posterior margin; last tergite moderately to strongly bilobate, each lobe bearing a group of strong short spines.

Aedeagus length 0.61 mm; mainpiece very strongly sinuate in lateral aspect, gradually widened from major bend to angulate ridged process; gonopore process comparatively wide, upper surface with small ridges, length subequal that of ridged process; membranous process large, angulate, immediately adjacent to and tapering tip slightly overlapping gonopore process (Fig. 39).

Etymology. Named in reference to the geographical distribution.

Distribution. Currently known only from the type locality in the Mpumalanga area of Natal Province (Fig. 83).