Coelometopon costatum, 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 costatum new species

(Figures 11, 12, 71)

Type Material. Holotype (male): South Africa: Transvaal Prov. , Zoutpansberg, 6 mi. NNE Louis Trichardt, 23° 1' S, 29° 43' E 5/21/1951; deposited in the LUM.

Diagnosis. Recognized among endroedyi group members by the elytra with flat, shining and relatively wide odd­numbered intervals separated by costate and granulate evennumbered intervals. Most similar to C. emarginatum in dorsal sculpture, but odd­numbered intervals smoother and wider, the costate portions of the even­numbered intervals are less interrupted, and the metasternum has very large, deep, strong walled punctures laterally. The aedeagi of the two species (Figs. 12, 14) bear a resemblance in having the mainpiece only slightly sinuate; the distal processes are distinctly species­specific, but do again show a relationship, when compared to other members of the endroedyi group.

Description. Size (length/width, mm x 100) holotype: body (length to elytral apices) 219/94, head 48/59, pronotum 48/78, elytra 141/94. Head and pronotal disc piceus, remainder of body and legs brown. Maxillary palpus length ca. 3/4 width of anterior margin of clypeus, last three palpomeres subequal in length and width. Mentum weakly produced apicomedially; depressed on each side of midline near base. Labral lobes very small. Mentum anterior margin weakly emarginate.

Large areas of clypeus, frons and pronotum devoid of granules, shining, including middle of median groove. Pronotum with sides angulate at midlength, emarginate in front of and straight behind angulation.

Elytral intervals: 1st, 3rd and 5th flat, shining, non­granulate, contrasting with costate portions of 2nd, 4th and 6th; 7th with unilinear row of fine, widely spaced granules.

Metasternum with very large, deep, strong walled punctures laterally, anterior carinae very strong, discal oval depression with posterior margin raised slightly. Females unknown.

Aedeagus length 0.55 mm; mainpiece nearly straight in lateral aspect, ridged process large, very angulate, apex well below level gonopore process tip; gonopore process about same length as ridged process and membranous process, in dorsal aspect forming nearly continuous straight line with margin of ridged process; membranous process wide (Fig. 12).

Etymology. Named in reference to the costate elytra.

Distribution. Currently known only from the type locality in the Zoutpansberg Mountains of Transvaal Province (Fig. 71).