Orphnus (Phornus) strangulatus Paulian, 1948

Figs 1R, 5 I–P, 6

Diagnosis

Orphnus strangulatus is most similar to O. parastrangulatus sp. nov. but can be separated from it in having frontoclypeus with higher transverse keel, slightly sinuate medially, about half as long as frontoclypeus, and abdomen longer and almost flat (in lateral view contour of abdominal sternites is almost straight).

Material examined

Holotype

DEMOCRATIC REPUBLIC OF CONGO: ♂, “MUSÉE DU CONGO BELGE KASAI [Democratic Republic of Congo] Coart / Boucomont det. 1927 Orphnus sp.? / R. DET. 5089 / HOLOTYPUS ” (MRAC).

Other material examined

DEMOCRATIC REPUBLIC OF CONGO: 2 ♂♂, Kasai, Luebo, 1 Apr. 1959, F. Francois (MHNG); 1 ♂, same locality, Oct. 1959, F. Francois (MRAC); 1 ♂, same locality, Dec. 1958, F. Francois (MRAC); 1 ♂, Kondue (BMNH); 2 ♂♂, Sankuru, Bena Bendi, Jan. 1895, L. Cloetens (IRSNB); 2 ♂♂, Mukenge Pogga (ZMHUB).

ZAMBIA: 1 ♂, Madona, Dec. 1907, Sh. Neave (MNHN).

Description

Male (Fig. 5I)

Body length 10.5–13.5 mm. Colour uniformly dark brown to black.

Anterior margin of frontoclypeus feebly convex medially, rounded laterally, with a keel-shaped border (Fig. 5 J– K). Frontoclypeus with low transverse carina slightly sinuate medially, about half as long as frontoclypeus, approximately on the line connecting anterior margins of canthi. Frontoclypeus concave and coarsely punctate posteriad of the carina.

Eyes relatively large: width about 1/5.3 the distance between eyes in dorsal view.Antennae 10-segmented, without malformed segments.

Pronotum widely rounded laterally, narrower than elytra, 1.5 times wider than length, 0.6 length of elytra (Fig. 1R). Anterior border wide, with almost smooth posterior margin. Basal border narrow, keelshaped, separated from pronotal disc by a smooth groove. Pronotal disc anteromedially very slightly flattened. Surface of pronotum covered with double puncturation composed of large rounded and minute punctures; large punctures cover sides of the pronotum and area near anterior border.

Scutellum narrowly rounded apically, about 1/14 the length of elytra.

Elytra about slightly longer than wide, with feeble marked humeral humps. Elytra widest approximately in the middle, with less rounded lateral margins than in previous species. First six to eight striae faintly visible as shallow grooves, without distinct rows of punctures. Elytra covered with sparse punctures becoming denser laterally and towards base.

Brachypterous. Wings vestigial, narrow, about ¾ the length of elytra. Stridulatory field: carinae separated by 1/30 length of the field in central ¼ rd (Fig. 5P).

Abdomen 1.3 times wider than long (measured in ventral view from anterolateral margins of sternite 2 to apex of pygidium). Abdominal sternite 8 medially about as long as sternites 6–7 combined. Pygidium visible from above, rounded apically. Plectrum trapezoidal, elongated, almost rectangular, with widely rounded apex (Fig. 5O). Lateral plate of abdominal sternite relatively large, as long as plectrum, with rounded apex.

Aedeagus with relatively long parameres (0.5 length of phallobase) without excavations. Apices of the parameres rounded in dorsal view and lateral view (Fig. 5 L–M).

Female

Unknown.

Variation

Except for body size and colour variation, examined specimens differ slightly in the shape of the frontoclypeal carina and the sculpture of the elytra and pronotum.

Distribution

O. strangulatus is known from a number of localities, chiefly on the Katanga Plateau (Fig. 6).