Niphadomimus Zherikhin, 1987

Zherikhin, 1987: 15 (species included: nigriventris, niger). Type species: Niphadomimus nigriventris Zherikhin, 1987 by original designation.

Diagnosis. Adults of the genus Niphadomimus can be immediately recognized from other wingless Asian weevils by the following unique combination of characters: (1.) rostrum longer than wide; (2.) prosternum anterior of procoxae with a shallow and broad depression (Fig. 11); (3.) mesoventrum at middle anterad of mesocoxae with distinct and sizable projection pointed ventrad, vertically sloped anteriorly and oblique posteriorly (Fig. 11). In its natural habitat Niphadomimus co-occurs with similarly wingless Colobodes Schoenherr and Niphadonyx Schenkling. Adults of these two genera are most easily separated from those of Niphadomimus by either widely separate procoxae and or by the claws having a sizable inner lobe (Meregalli 2013, fig. 2M), respectively.

The original generic description by Zherikhin appears adequate, even though it did not refer to the internal structures, such as the proventiculus, or male and female genitalia. These and a few other characters are mentioned below in an attempt to elaborate the original Zherikhin description, which should also be consulted.

Description. Fully apterous genus of Molytinae with elytra fused to each other and to metathorax. Length 2.45–6.27 mm. Colour dark, from reddish-brown to almost black; legs and elytra with bluish or reddish hue, sometimes partly bicoloured (Fig. 9A–B), never metallic or shiny. Antennal funicle with seven antennomeres. Procoxal cavities adjacent to each other (Fig. 11); prosternum anterad of procoxal cavities with depression at middle (Fig. 11), this depression normally in form of wide longitudinal groove marked by ridge on each side (Fig. 11H). Ventral surface of thorax and abdomen with numerous punctures (Fig. 11). Mesoventrum at middle anterad of mesocoxae with distinct and sizable projection pointed ventrad, vertically sloped anteriorly and oblique posteriorly (Fig. 11). Entire length of meso-metaventral suture between metacoxae formed by deep narrow transverse groove (Fig. 11) often separated at middle by septum into two equal parts (Fig. 11I). All femora with single variously developed femoral tooth at distal third. Scutellum with minute externally visible part. Elytra with nine punctate striae, odd interstriae with our without tubercles, some of which might be markedly enlarged (Fig. 4A–C). Proventriculus sclerotized and easily distinguishable (Fig. 8E). Male genitalia. Male abdominal sclerite 9 variously asymmetrically V-shaped (Fig. 3E), with long apodeme (= “spiculum gastrale”); sternite 8 consisting of two hemisternites (Fig. 3E). Aedeagus symmetrical, longer than wide, almost parallel sided and evenly rounded, without internal sclerites and with partly sclerotized walls on endophallus proximad to it (Fig. 3F–H); aedeagal apodemes about 1.5x as long as aedeagus; tegmen fully closed dorsally, with two asetose and weakly sclerotized parameral lobes each longer than wide. Female genitalia. Sternite 8 Y-shaped with setose apical lobes (Fig. 1G) and long apodeme; sternite 9 consisting of two hemisternites each formed by larger basal piece (= “coxite”) and smaller apical piece (= “stylus”) (Fig. 1E, F); spermatheca present (Fig. 2E).