Memptorrhynchus Iablokoff-Khnzorian, 1960

ROBERTO CALDARA, CHARLES W. O’BRIEN & MASSIMO MEREGALLI, 2017, A phylogenetic analysis of the aquatic weevil tribe Bagoini (Coleoptera: Curculionidae) based on morphological characters of adults, Zootaxa 4287 (1), pp. 1-63 : 33-34

Genus Memptorrhynchus Iablokoff-Khnzorian, 1960 resurrected name

Memptorrhynchus Iablokoff-Khnzorian, 1960: 253 [type species: Memptorrhynchus ripicola Iablokoff-Khnzorian, 1960 (= Bagous brevipennis Kirsch, 1878 )]. Caldara & O'Brien 1998: 137. Alonso-Zarazaga & Lyal 1999: 88. Caldara 2013: 172.

Diagnosis. Body broad-oval and robust. Rostrum unusually flattened at apex (char. 8.1), with lateral plica (char. 9.1); curvature of ventral margin in lateral view strong (char. 7.1), at basal 2/3 with row of sparse, regularly spaced setae along lateral margin close to ventral margin (char. 13.1). Forehead between eyes not sulcate nor foveate (char. 24.0). Pronotal disc moderately to strongly transversely convex. Postocular lobe ventrally indistinct, not raised, not forming discontinuity with anterior prosternal margin (char. 30.0). Prosternal canal weak (char. 31.0). Side margins of prosternum not clearly raised (char. 33.0). Elytra with setae on odd-numbered intervals surrounded by rosette of scales of same color; declivital callus absent (char. 36.0). Outer margin of tibiae, especially on hind tibiae, straight or nearly so toward apex (in lateral view) (char. 48.0); tibiae denticulate along inner margin, sometimes with denticles stouter and more numerous on midtibiae; tarsi short, tarsomere 3 cordate. Penis with long apodemes (char. 110.0). Endophallus with basal sclerite complex formed by elongate curved sclerites (char. 90.2). Apodemes of spiculum ventrale fully bifurcated, arising laterally on plate of sternite, apparently forming two straight rods with arms (char. 114.2).

Remarks. Monophyly of the species referred to this genus was supported in all analyses.

Memptorrhynchus is characterized by the poorly developed, barely distinguishable prosternal canal, the tibiae almost straight to apex along the outer margin, the tarsi short with tarsomere 3 broadly cordate, and the male genitalia which present certain similarities with those of Hydronomus (i.e., the features of the sclerite complex at the base of the endophallus). This is a homogeneous group and its species show six synapomorphies (char. 7.1, 8.1, 9.1, 13.1, 90.2, 114.2) in nongenital characters (rostrum strongly curved and with flat apex with lateral carinae, and with row of lateral setae) as well as genital morphology (shape of the penis and especially of the spiculum ventrale with apodemes strongly divergent and arising laterally on plate). The bulk of this group is present in the Afrotropical region with three extralimital species (two Indian and one Palaearctic).

Species included: AFR: ¹ Memptorrhynchus bergensis (Marshall, 1953) n. comb., ¹ M. crassus (Hoffmann, 1968) n. comb., *¹ M. crispus (Faust, 1899) n. comb., ¹ M. gaillardi (Hustache, 1936) n. comb., ¹ M. polysignatus (Hoffmann, 1968) n. comb., ¹ M. vafer (Marshall, 1958) n. comb.; ORR: ¹ M. luteitarsis (Hustache, 1926) n. comb., ¹ M. ovoideus (Hustache, 1926) n. comb.; PAL: *² M. brevipennis (Kirsch, 1878) n. comb.