Stereodermus platycornis Mantilleri, sp. nov.

(Figs. 9–18)

Type material. Holotype: ♂, Peru, Tambopata prov., Madre de Dios Dpto., 15 km NE Puerto Maldonado Reserva, Cuzco Amazónico, 12°33'S 69°03'W, 200 m, camp, 21.VI.1989, J.S. Ashe & R.A. Leschen, at light, prép. micro. n°KUNHM-AM 0 0 0 0 1 (KUNHM).

Paratypes: 1 ♀, idem holotype, prép. micro. n° KUNHM-AM 0 0 0 0 2 (KUNHM); 1 ♂, idem, 2.VII.1989 (KUNHM); 1 ♂, Madre de Dios, Cocha Salvador, Reserved Zone Manu National Park, 310 m, 12°00'13''S 71°31'36''W, 20.X.2000, R. Brooks, on Xylariaceae (KUNHM); 1 ♀, Dept San Martin, vicinity of Rioja, 24.IX.1936, F. Woytkowski (KUNHM) .

Description. Length from apex of rostrum to apex of elytra: 4.6–5.8 mm; length from apex of pronotum to apex of elytra: 3.5–4.8 mm; width across humeral calli: 0.7–0.9 mm. Habitus: Fig. 9.

Brown red with light darker postmedian blotch on elytra.

Head (Fig. 10) broader than long, punctate, base slightly concave. Temples shorter than eyes, with few squamous setae on upper part. Cephalic median groove weak or missing. Vertex, metarostrum and mesorostrum grooved. Sides of metarostrum (Fig. 11) glabrous. Prorostrum shorter than head, metarostrum and mesorostrum together, its length similar in both sexes. Venter of head and metarostrum with dull longitudinal median shallow groove, almost glabrous. Venter of mesorostrum with squamous setae. Antennal scape longer than antennomeres 2–3 together; articles 2–8 much broader than long, cylindrical; articles 3–8 with one row of raised setae; articles 9– 11 strongly laterally flattened in both sexes (Fig. 12).

Pronotum (Fig. 10) shiny, punctate, with prostrate fine setae; longitudinal median groove deeper at base, weakly connected to collar constriction. Metasternum with large punctures on sides; venter longitudinally grooved. Elytra glabrous, shiny, base straight to weakly concave, humeral calli not projecting forward; striae 3–10 strongly punctate. Femora unarmed, glabrous except few thick setae at base.

Abdomen (Fig. 13) with sternites III–IV punctate (but without row of punctures at apex of sternite IV), longitudinally depressed; sternites V–VI with fine line of shallow setose punctures; sternite VII of male with several large punctures, almost smooth in female (Fig. 14). Tergite VIII of female strongly dentate, with apical median notch; epipleurites VIII with short spiculum; spermatheca: Fig. 18. Sternites VIII–IX of male: Fig. 15. Tegmen with elongate, thin parameroid lobes (Fig. 16). Penis: Fig. 17.

Etymology. The specific epithet refers to the strongly flattened articles 9–11 of antennae.

Remarks. Stereodermus platycornis sp. nov. is easily differentiated from all other taxa of the genus: it is the sole known species with articles 9–11 of antennae flattened. Its affinities with other Stereodermus are unclear. In the key given by Mantilleri & Sforzi (2006), it is close to S. puncticollis Sharp, 1895, known from Central America. Smaller size, shorter parameroid lobes and, above all, flattened antennomeres, separate the two species.