Afrosmicronyx Hustache, 1935

Haran, Julien & Perrin, Hélène, 2017, Revision of the genus Afrosmicronyx Hustache (Coleoptera, Curculionidae, Curculioninae), Zootaxa 4365 (2), pp. 132-148 : 133-134

Afrosmicronyx Hustache, 1935

Smicronyx (Afrosmicronyx) Hustache, 1935a: 29

Redescription (updated from Hustache 1935). Body length 3.1–7.0 mm. Colour. Body integument brownish to black; vestiture of elytra consisting of short recumbent and overlapping scales, rounded or slightly longer than wide, generally concealing integument (in fresh specimens); scales on elytra mostly black, brown or grey, usually with paler shades, spots, stripes or bands. Head. Rostrum generally longer than head plus prothorax, rarely slightly shorter, thinner than apex of femora, sides parallel in apical half, dorsally punctate and covered by scales in basal third, punctate and bearing scale (males), smooth and shiny (females) in apical third; with transverse dorsal furrow at base, sometimes reduced or concealed by scales; base of rostrum in lateral view forming a blunt projection above apex of scrobes; rostrum moderately and regularly downcurved; head short, wider than long; eyes subcontiguous ventrally, space between them ventrally always narrower than width of antennal clubs; antennae reddish or dark brown, inserted near middle of rostrum in females but antemedially in males; scapes thin, arcuate at base, clavate at apex; funicles 7-segmented, segment 1 longer than wide, 2 equal in length or shorter, 3–7 slightly longer than wide or transverse, widening toward club. Prothorax. Isodiametric or transverse, sides rounded, narrowed at apex, densely punctate, integument shiny, visible through scales. Elytra. Longer than wide (ratio w/l: 0.55–0.72), sides subparallel or moderately rounded in basal two thirds, rounded in apical third, humeri raised, space between them larger than greatest width of prothorax, declivital callosities present at apex of interval 3, followed by a depression, striae narrow, interstriae flat and wide, much larger than striae; scutellum small, shiny and flat. Abdomen. Underside covered by scales similar in colour and shape to those of elytra, integument shiny with rounded punctures at insertion of scales, ventrites 1 and 2 elongate, equal or subequal in length, 2 as long as 3–5 or a little shorter, 5 concave, concavity more pronounced in males. Legs. Black to reddish, covered with recumbent scales mixed with raised setiform scales; femora clavate, armed with a strong ventral tooth, largest on profemora; tibiae armed with ventral tooth or thickening proximally near middle, largest on protibiae, tooth of protibiae acute in females, obtuse in males, space between tooth and apex of profemora bearing a row of stiff setae, tibial spurs large and slightly curved; tarsi with 3rd tarsomere broadly bilobed; claw connate at base, slightly divergent. Sexual dimorphism. Males differing from females by slightly shorter and stouter rostrum, anteriorly more coarsely punctate and densely squamose squamose, less sharply pointed tibial teeth and more pronounced concavity on ventrite 5. Genitalia. Structure of male terminalia of pedal type. Penis short or elongate (ratio w/l: 0.28–0.58), curved in lateral view.

Type species: Smicronyx (Afrosmicronyx) giganteus Hustache, 1935

Differential diagnosis. The furrow at the base of the rostrum and the connate condition of the tarsal claws are typical of the tribe Smicronychini . Afrosmicronyx is distinguished from other continental Afrotropical Smicronychini by its femora bearing a strong ventral tooth and its protibiae bearing a distinct ventral tooth or thickening near middle or antemedially. In Madagascar Afrosmicronyx is distinguished from the endemic genus Topelatus its body length (more than 3 mm).

Life history. Species whose life histories are documented are associated with hemiparasitic Orobanchaceae ( Striga, Anderson & Cox 1997 ; Sopubia, Marshall 1940 ). Their larvae develop in seed capsules (forming a gall or not) or in galls on the roots of their host plants. The life history of most species is unknown.