Smicronyx bisignatus Hoffmann, 1968

Haran, Julien, 2018, A review of the genus Smicronyx Schoenherr (Coleoptera, Curculionidae, Curculioninae) in tropical Africa, Zootaxa 4508 (2), pp. 267-287 : 269

Smicronyx bisignatus Hoffmann, 1968

Figs 1A , 3A , 5A

Smicronyx bisignatus Hoffmann, 1968: 170

Material examined. Holotype ♂: [ Cameroun] ‘N’Goum, 40 km au sud du lac Tchad. 11.viii.1963 ’ ‘Cameroun. Bas-Chari, 1963. J. Péricart, coll.’ ‘S/ Convolvulacée. gen.’ ‘TYPE’ ‘Muséum Paris. CoLL. J Péricart’ ‘ Smicronyx (s. st) bisignatus m. A. Hoffmann det.’, (with red type label, MNHN). Paratypes. Data as for Holotype, (6♂, 4♀, MNHN). Other material. Data as for holotype (4♂, 1♀, MNHN; 7♂, 4♀, MNHN); Cameroun, Bas-Logone, réserve forestière de Logone-Birni, 2.viii.1963 (1♀, MNHN); Mali, (« Soudan Français »), Région de la Volta, Sikasso-Bobo-Diolassou, v–vi.1900, A. Chevalier (1♂, MNHN).

Diagnosis. Body length 2.1–2.2 mm. Colour. Body integument reddish, except antennal club, prothorax, suture of elytra and tarsi which are brownish; vestiture of elytra comprising rounded, recumbent, slightly overlapping scales, moderately to distinctly longer than wide, not concealing integument, and series of semi-erect scales on all interstriae, generally whitish on interstriae 3–5–7; scales of elytra pale brown, usually darker along interstriae 1–2 at least at base, sometimes whitish along interstria 3. Head. Rostrum moderately arched in lateral view, longer than head capsule + prothorax, covered with scales in basal 2/3 (♂) or 1/3 (♀). Prothorax. Slightly wider than long (w/l ratio: 1.10), sides moderately downcurved, constricted apically, almost half as wide as base at apical margin. Elytra. Subparallel in basal two thirds (w/l ratio: 0.62), rounded toward apex in apical third. Legs. Femora clavate, armed with a distinct ventral tooth, tibiae straight. Genitalia. Penis elongate (w/l ratio: 0.56), sides straight, subparallel, slightly converging in apical 1/3, apex rounded, slightly and regularly curved in lateral view ( Fig. 5A ).

Life history. Adults were collected on an unidentified Convolvulaceae , from May to August.

Distribution. Cameroon, Mali.

Discussion. Smicronyx bisignatus belongs to the S. remaudierei species group (see discussion on S. remaudierei ). WIthin this species group, it can be distinguished from S. remaudierei by the absence of a short line of white scales at the base of the prothorax near the scutellum. It can be distinguished from S. adjamati and S. crassithorax by the presence of a ventral tooth on the femora, which is absent in the latter species. It can be distinguished from S. zambianus by its reddish integument and its elongate elytra of w/l ratio: 0.62 (black integument and w/l ratio: 0.70 in S. zambianus ). Smicronyx bisignatus is also the only species having a widely rounded penis apex ( Fig. 5A ).

Figures

FIGURE 1. Habitus of species of Smicronyx from tropical Africa (Part 1). A. Smicronyx bisignatus Hoffmann, holotype ♂. B. S. remaudierei Hoffmann, holotype ♂. C. S. adjamati, sp. n., holotype ♂. D. S. crassithorax sp. n., paratype ♀. E. S. zambianus sp. n. holotype ♂. F. S. syriacus Faust, specimen from Israel (♂). G. S. gossypii Marshall, holotype ♂. H. S. albosquamosus Wollaston, specimen from Israel (♂). I. S. pauperculus Wollaston, specimen from Tanzania (♂). J. S. rufus sp. n., holotype ♂. K. S. zonatus sp. n., holotype ♂. L. S. kenyanus sp. n., holotype ♂. Scale bars (A to L): 1 mm.

FIGURE 3. Head and prothorax in lateral view of species of Smicronyx from tropical Africa (Part 1). A. Smicronyx bisignatus Hoffmann, holotype ♂. B. S. remaudierei Hoffmann, holotype ♂. C. S. adjamati, sp. n., holotype ♂. D. S. crassithorax sp. n., paratype ♀. E. S. zambianus sp. n. holotype ♂. F. S. syriacus Faust, specimen from Israel (♂). G. S. gossypii Marshall, holotype ♂. H. S. albosquamosus Wollaston, specimen from Israel (♂).

FIGURE 5. Penis of Smicronyx from tropical Africa, in dorsal (left) and lateral (right) view. A. Smicronyx bisignatus Hoffmann, holotype ♂. B. S. remaudierei Hoffmann, holotype ♂. C. S. adjamati, sp. n., holotype ♂. D. S. crassithorax sp. n., paratype ♀. E. S. zambianus sp. n. holotype ♂. F. S. syriacus Faust, specimen from Israel (♂). G. S. gossypii Marshall, holotype ♂. H. S. albosquamosus Wollaston, specimen from Israel (♂). I. S. pauperculus Wollaston, specimen from Tanzania (♂). J. S. rufus sp. n., holotype ♂. K. S. zonatus sp. n., holotype ♂. L. S. kenyanus sp. n., holotype ♂. M. S. namibicus sp. n., holotype ♂. N. S. kiboanus Voss, paratype ♂. O. S. guineanus Voss, specimen from Senegal (♂). P. S. buchnerae sp. n., holotype ♂. Scale bars (A to N): 100 µm.