Coelometopon madidum Janssens

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 madidum Janssens

(Figures 47, 48, 86)

Coelometopon madidum Janssens, 1972 ; 391.

Type Material. Holotype (male): Tanzania, Uluguru Montains, "Morning Side"; deposited in the MRAC. [labels: HOLOTYPUS //Tanzanie: Mts Uluguru Morning Side , alt. 1600 m. 21–29/VI/71 sur roche ruisselante// Coll. Mus. Tervuren Mission Mts Uluguru L. Berger, N. Leleup J. Debecker V /VIII/71// Prép. Micr. No 720117.2// E. Janssens det., 1972 Coelometopon madidum n. sp. //DIGITAL IMAGE captured 2004 P. D. Perkins].

Diagnosis. Recognized by the very large size, ca. 3.40–4.50 mm (one of the largest species in the family), and the large, sharp tubercles on the pronotal lateral margin (Fig. 47).

Description. Size (length/width, mm x 100) holotype: body (length to elytral apices) 3.42/1.50, head 0.50/0.82, pronotum 0.73/1.22, elytra 2.32/1.50. Dorsum piceous to black, legs dark brown to piceous. Frons with large non­granulate areas, granules near eyes, near ocelli and forming midlongitudinal band of granules in anterior 1/2; anterior margin emarginate, on same plane as clypeus. Clypeus granulate laterally and on very slightly raised area in middle near anterior margin, otherwise smooth and shining. Largest granules of frons and pronotum similar in size. Labrum set beneath margin of clypeus, lobes small, triangular in ventral aspect; area in front of each clypeal angle raised and bearing tuft of setae. Maxillary palpi short, ca. 3/4 width of anterior margin of clypeus, last three articles subequal in length, last article suboval. Mentum with two depressions.

Pronotum with large non­granulate areas on disc; sides straight or weakly arcuate in front of and behind widest part; lateral depressions very wide, strongly tuberculate at lateral margin, otherwise sparsely granulate, non­granulate surfaces shining; small, nearly oval fovea posteriorly. Median groove location demarcated by nearly parallel bands of granules, each band two or three granules wide; interior of groove area granulate in anterior and posterior depression, shining and virtually flat on non­granulate middle area; two low, granulate callosities on each side of median groove.

Elytral serial punctures small, deep, closely spaced serially, width ca. 1/3 width of intervals; granules separating serial punctures prominent, length only slightly less than that of punctures. Elytral intervals: even numbered intervals with long granulate callosities, all mostly similar in height, 4 on 2nd, 3 on 4th, and ca. 5 on 6th, inter­callosity areas smooth, shining; odd­numbered intervals each with unilinear row of granules; lateral margin in dorsal aspect formed by granules on raised 8th interval (pseudoepipleuron).

Prosternum with low midlongitudinal carina. Mesosternal process transverse, narrow, margin arcuate. Metasternum strongly carinate behind mesocoxae; midlongitudinal fovea in basal 0.75 wide, deep; disc on each side of fovea sparsely finely punctate, weakly shining; lateral 1/3 very coarsely punctate; posterior margin depressed in front of metacoxae. Abdomen with intercoxal sternite and adjacent part of first ventrite conjointly deeply concave; intersegmental areas deeply impressed.

Sixth ventrite in male shallowly impressed medially; in female very weakly tumid in basal 1/2, apically strongly arcuate. Female differing from male in following: pronotal disc more humped, foveae deeper and median groove wider; elytral callosities slightly larger; elytral 8th interval (pseudoepipleuron) anterior 1/ 2 in lateral aspect markedly more sinuate. Female last tergite apical margin arcuate with very faint apicomedian emargination, fringed with row of strong spines; males lacking spines. Protibiae sexually dimorphic, in male more strongly built and with ventral surface sinuate and distal 1/2 slightly concave and with row of long setae; mesotibia of male also dimorphic, sinuate, but much less so than protibia.

Aedeagus length ca. 1.20 mm; distal area enlarged, complex; membranous process spinose, large, expandable; presumed gonopore process distally wide and thin; parameres sinuate, joined near base of mainpiece, attaining proximal part of enlarged distal area; mainpiece with internal sclerotized parts (pumping mechanism?) (Fig. 48). Holotype aedeagus flattened and distorted by slide mounting.

Distribution. Currently known only from the type locality in the Uluguru Mountains of Tanzania (Fig. 86).