Menomadraena sembella, Perkins, 2017

Perkins, Philip D., 2017, Hydraenidae of Madagascar (Insecta: Coleoptera), Zootaxa 4342 (1), pp. 1-264 : 175-176

Menomadraena sembella , new species

Figs. 166 (habitus), 168 (aedeagus), 223 (spermatheca), 299 (map) Type Material. Holotype (male): Fianarantsoa, Amparihibe, flight intercept trap, 15° 2' S, 49° 34' E, 1 ii–30 iii 2003, K. A. Jackson, D. Carpenter ( BMNH) . Paratypes (113): Same data as holotype (1 BMNH). Fianarantsoa, 40 km S Ambalavao, Andringitra Reserve , montane rainforest, ridge forest, sifted litter (leaf mold, rotten wood), elev . 1275 m, 22° 12' S, 46° 58' E, 15 x 1993, B. L. Fisher (793) (4 FMNH); R.S. Ivohibe, 6.5 km ESE Ivohibe , camp III, sifted litter (leaf mold, rotten wood) montane rainforest, elev . 1575 m, 22° 29.8' S, 46° 57.3' E, 24–30 x 1997, B. L. Fisher (1751) (108 FMNH).

Differential Diagnosis. Similar to M. andringitra in having a small oval posteromedian depression of the metaventrite; differing therefrom in having a flat discal area of the metaventrite and a less convex body shape. The aedeagi of the two species show some resemblance but differ significantly in shapes of the distal part of the main piece and the parameres ( Figs. 168, 169).

Description. Size: holotype (length/width, mm): body (length to elytral apices) 1.85/0.88; head width 0.52; pronotum 0.38/0.73, PA 0.63, PB 0.60; elytra 1.19/0.88. Size range ca. 1.79–1.97 mm. Dorsum and venter reddish brown, legs brown.

Maxillary palpi short, last palpomere distinctly shorter than first antennomere. Last antennomere longer than penultimate. Labrum bilobed, pubescent, originating under overhanging anterior margin of clypeus. Subocular groove for antenna deep and wide. Clypeus anterior margin emarginate. Clypeus and frons with small, dense, flat or slightly rounded granules, those on frons much larger, contiguous; setae very small and inconspicuous.

Pronotal disc with contiguous flat circular granules; lateral explanate areas and two very small areas basally without granules, shining; shallow midlongitudinal sulcus in anterior 2/3; posteroadmedian foveae confluent with median impression in midline. Postocular emarginations deep.

Elytral suture raised. Each elytron with three costae, first (from suture) terminating at ca. posterior ¾, second arcuate and continiuing to apices, third terminating at ca. midlength. Each costa with unilinear row of very small granules, each with short recumbent seta. Areas between costae each with three rows of small punctures, each puncture with minute granule and seta at anterior margin. Area between third costa and explanate margin with five very irregular rows of punctures.

Mentum punctate and pubescent; postmentum sparsely pubescent, shining. Genae microreticulate, dull, without posterior ridge. Mesoventrite with very low tubercle on intercoxal process. Metaventrite virtually nonpubescent; disc flat and weakly shining, with small basomedian depression; lateral areas dull, very finely microreticulate ( Fig. 166 ). Abdominal ventrites very finely microreticulate, with very fine, very short, and exceedingly sparse setae, almost glabrous. Mesotibia straight, pro- and metatibiae slightly arcuate toward midline.

Etymology. "Coin"; named in reference to the flat circular granules of the pronotum.

Figures

FIGURE 166. Menomadraena sembella, holotype, habitus dorsal, lateral, and ventral.