Afrosmicronyx angolanus (Hustache, 1935) Haran & Perrin, 2017

Haran, Julien & Perrin, Hélène, 2017, Revision of the genus Afrosmicronyx Hustache (Coleoptera, Curculionidae, Curculioninae), Zootaxa 4365 (2), pp. 132-148 : 137-138

Afrosmicronyx angolanus (Hustache, 1935) comb. n.

Figs 2D , 3D , 5D , 6D

Smicronyx (Chalybodontus) angolanus Hustache, 1935b: 186

Material examined. Holotype ♂: [Angola] ‘Ebanga nov.’ ‘Angola, Mission sc. Suisse. 1932–1933 ’ ‘Museum Paris. 1968. col. A. Hoffmann’ ‘ Smicronyx (Chalybodontus) angolanus Hust’ (fitted with a red holotype label reading: “HOLOTYPE/ Afrosmicronyx angolanus / Hustache, 1935/ Haran & Perrin des. 2017”; MNHN, Hoff.coll). Other material. Angola, Kalukembe, xii.1932, Mission sc. Suisse (1 ♂, MNHN, Gene.coll).

Redescription. (♂) Body length 4.6 mm. Colour. Body integument black; vestiture consisting of short rounded recumbent scales, black with a copper shine. Head. Rostrum as long as head plus prothorax, thick, moderately downcurved, densely punctuate, smooth at apex, sides bearing two carinas merged near antennal insertion, transversal furrow at base of rostrum shiny, head short; antennae with segment 1 as long as 2 + 3. Prothorax. Isodiametric, widest proximally near middle, greatly narrowed at apex, densely and coarsely punctuate, median line present and slightly raised. Elytra. Sides rounded, widest near middle (ratio w/l: 0.65), humeri raised, declivital callosities present but weak, followed by a depression, striae narrow, interstriae flat and wide; scutellum small, shiny. Abdomen. Underside covered with dark scattered scales with a metallic-copper shine, ventrites 1–2 sub-equal, shorter than 3+ 5. Legs. Femora clavate, armed with one ventral tooth; pro- and mesotibiae straight, armed with one ventral tooth proximally near middle; fore-tibiae bisinuate, thickened near middle. Genitalia. Penis short (ratio w/l: 0.56), sides rounded, converging apically, apex rounded, curvature in lateral view stronger in apical half ( Fig. 6D ). Female not known.

Life history. Unknown. Adults collected in November and December.

Distribution. Angola.

Discussion. This species is most similar to Afrosmicronyx maerens Marshall. The two species can be distinguished by the colour of the coating (black in A. angolanus , variegated grayish and brownish in A. maerens ), the tooth on the protibiae (present in A. angolanus , tibiae only thickened in A. maerens ) and the shape of the penis (sides rounded in A. angolanus , narrowed in apical half in A. maerens ). Hustache placed this species, with doubts, in the subgenus Chalybodontus of Smicronyx (Hustache, 1935) . It is here transferred to Afrosmicronyx due to the presence of scales on all of its elytra, the presence of a ventral tooth on the femora and tibiae as well as its Afrotropical distribution. Contrary to what is stated in the description, the rostrum bears a ventral tooth at its base. This condition is encountered in all species of Afrosmicronyx and therefore not restricted to the subgenus Chalybodontus . Of the several type specimens mentioned by Hustache, the one used for description (with labels corresponding to the type locality) was located in the Hoffmann collection ( Perrin, 1998).

Figures

FIGURE 2. Habitus of species of Afrosmicronyx. A. Afrosmicronyx giganteus (Hustache), neotype ♀. B. A. quadrituberculatus (Hustache),lectotype ♂.C.A.sopubiae(Marshall),lectotype ♂.D.A.angolanus (Hustache),holotype ♂.E.A.maerens (Marshall), lectotype ♂. F. A. dorsomaculatus(Cox), specimen from Sudan (♀). G. A. mirei sp.n., holotype ♂. H. A. armipes (Voss), holotype ♂.I. A. madagascariensissp.n., holotype♂. J. A.umbrinus(Hustache) lectotype ♀.Scale bars (A to J): 0.2 mm.

FIGURE 3. Head and prothorax in lateral view of species of Afrosmicronyx. A. Afrosmicronyx giganteus (Hustache), neotype ♀. B. A. quadrituberculatus (Hustache), lectotype ♂. C. A. sopubiae (Marshall), lectotype ♂. D. A. angolanus (Hustache), holotype ♂. E. A. maerens (Marshall), lectotype ♂. F. A. dorsomaculatus (Cox), specimen from Sudan (♀). G. A. mirei sp. n., holotype ♂. H. A. armipes (Voss), holotype ♂.

FIGURE 5. Ventrites of Afrosmicronyx spp.. A. Afrosmicronyx giganteus (Hustache), neotype ♀. B. A. quadrituberculatus (Hustache), lectotype ♂. C. A. sopubiae (Marshall), lectotype ♂. D. A. angolanus (Hustache), holotype ♂. E. A. maerens (Marshall), lectotype ♂. F. A. dorsomaculatus (Cox), specimen from Sudan (♀). G. A. mirei sp. n., holotype ♂. H. A. armipes (Voss), holotype ♂. I. A. madagascariensis sp. n., holotype ♂. J. A. umbrinus (Hustache), lectotype ♀. Scale bar = 1 mm.

FIGURE 6. Penis of Afrosmicronyx species, dorsal (left) and lateral (right) view. A. Afrosmicronyx giganteus (Hustache), specimen from Cameroon. B. A. quadrituberculatus (Hustache), lectotype. C. A. sopubiae (Marshall), lectotype. D. A. angolanus (Hustache), holotype. E. A. maerens (Marshall), lectotype. F. A. dorsomaculatus (Cox), specimen from Mauritania. G. A.mirei sp.n., holotype.H.A.armipes (Voss),holotype.I. A.madagascariensis sp. n., holotype.J.A.umbrinus (Hustache), specimen from Cameroon.Scale bar = 200 µm.