Geotragus Schoenherr, 1845

Ren, Li, Alonso-Zarazaga, Miguel A. & Zhang, Runzhi, 2013, Revision of the Chinese Geotragus Schoenherr with description of three new species (Coleoptera: Curculionidae: Entiminae), Zootaxa 3619 (2), pp. 161-182 : 163

Geotragus Schoenherr, 1845

Geotragus Schoenherr, 1845: 411 . Type species: Geotragus himalayanus Boheman, 1845 . = Taphrorhynchus Schoenherr, 1847: 33 . Type species: Taphrorhynchus assamensis Schoenherr, 1847 . Synonymy by Marshall, 1916: 201.

Diagnosis. Body length 4.90–7.80mm. Vestiture of round to oval, often metallic scales. Rostrum with scrobes deep and curving downwards at some distance in front of eyes, posteriorly slightly dilated, equal in depth throughout. Mandibles with distinct apical-lateral scars. Prementum in ventral view entirely covering maxillary palps, each apicolateral edge with one seta. Antennae with scape reaching between fore margin and middle of eye when at rest. Prothorax with sparse vibrissae on the lateral margin behind eyes, postocular lobes not developed. Metanepisternal suture not complete, metanepisternum fused with metaventrite posteriorly. Abdomen with the intercoxal process narrower than the metacoxae.

Description. Body length 4.90–7.80mm, elongate oval, usually with round to oval, often metallic scales. Rostrum longer than head and continuous with it, in dorsal view lateral margins subparallel, dorsal surface slightly constricted at antennal insertion, base not or only slightly broader than frons, apex scarcely emarginate; scrobes deep and curving downwards at some distance in front of eyes, posteriorly slightly dilated, equal in depth throughout; in lateral view, ventral margins of rostrum and head forming an obtuse angle; mandibles with distinct apical-lateral scars, base of scars more or less cylindrically projecting; epistome V-shaped, without scales, parepistome and postepistome shallowly depressed; pterygia prominent. Prementum in ventral view entirely covering maxillary palps, each apicolateral edge with one seta. Eyes lateral, oval, moderately flat to strongly convex. Antennae with scape reaching between fore margin and middle of eye when at rest, slender at base, gradually clavate; funicle with two basal desmomeres elongate, desmomere 1 wider than 2, 3–6 subequal and moniliform, 7 longer and subconical; club elongate oval, 3-segmented, uniformly pubescent. Pronotum truncate at base and apex, sides evenly rounded, greatest width at midpoint, gradually constricted to both ends, anterior margin slightly narrower than posterior, posterior margin narrowly and slightly carinate, apex with distinct curved fine and sparse vibrissae behind eyes, postocular lobes not developed, gular margin more or less sinuate. Scutellum very small to large, reddish brown to black, glabrous, triangular, pointed. Elytra in dorsal view elongate ovate, base truncate and elevated as prominent flange, without humeral callus, lateral margin not or scarcely sinuate above the metacoxae; elytra strongly constricted beyond declivity towards apex; striae distinct, narrow, with minute, elongate, moderately deep punctures, punctures separated by a distance similar to the length of two or three punctures. Prosternum with procoxae inserted closer to front than to hind margin; mesepimeron much smaller than mesanepisternum; metaventrite hardly longer between meso- and metacoxae than mesocoxal length, metanepisternum fused with it behind, metanapleural cleft therefore distinct only in the cephalic half or 3/4, metacoxae reaching margin of elytra. Metathoracic wings absent. Abdomen with the intercoxal process narrower than the metacoxae and rounded in front, ventrite 2 along midline longer than 3 and 4 combined, suture I bisinuate; ventrites 3 and 4 equal or subequal in length; ventrite 5 longer than 3 and 4 combined, with a basal longitudinal groove on each side close to lateral margins, extending from base to midpoint ( Fig. 2 G, g) in females. Legs slender, femora clavate, front pair longer, their femora thickened; protibiae curved and internally denticulate in both sexes, apex only projecting inwards, not projecting outwards, with long, thick, dense bristles on apical margin; apex of metatibiae with an evident outer bevel, margin of corbel slightly ascending along dorsal edge; tarsi long and broad, tarsomere 2 narrower than 1, tarsomere 3 distinctly wider at apex than 2, broadly cordate, rather deeply emarginate; onychium with tarsomere 4 visible and tarsomere 5 slender; claws simple, connate at base; tarsi with dorsal setae fine and dense, underside with thick soles.

As a result of our studies, the Chinese species can be separated by the use of the following key

Figures

FIGURE 2. Geotragus tuberculatus Chen: A male ventrites, ventral view B male metendosternite, dorsal view C male sternites VIII and IX, dorsal view D penis, dorsal view E penis, lateral view F tegmen, dorsal view G female ventrites, ventral view (g = groove) H sternite VIII and female genitalia, lateral view I coxites and styli, dorsal view J bursal sclerites, lateral view K spermatheca, lateral view. Scales: 0.5 mm.