Menomadraena nitedula, Perkins, 2017

Perkins, Philip D., 2017, Hydraenidae of Madagascar (Insecta: Coleoptera), Zootaxa 4342 (1), pp. 1-264 : 171-172

Menomadraena nitedula , new species

Figs. 162 (habitus), 164 (aedeagus), 299 (map)

Type Material. Holotype (male): Fianarantsoa, Res. Andringitra, 8.5 km SE Antanitotsy , sifted litter (leaf mold, rotten wood), montane rainforest, elev. 1990 m, 22° 10' S, 46° 58' E, 6 iii 1997, B. L. Fisher (1526) ( FMNH) ; Paratypes (14): Same data as holotype (10 FMNH); Fianarantsoa, Res. Andringitra, 8.5 km SE Antanitotsy, sifted litter (leaf mold, rotten wood), montane rainforest, Sylvian , elev. 1990 m, 22° 10' S, 46° 58' E, 6 iii 1997, B. L. Fisher (1524) (4 FMNH).

Differential Diagnosis. One of the larger species in the genus, ca. 1.91–2.24 mm. Similar in color (reddish brown) and habitus to M. ivohibe ; differing therefrom in larger size (ca. 2.00 vs. 1.85 mm), having more strongly arcuate lateral margins of the pronotum, and having a shorter metaventral midlongitudinal impression. The aedeagi of the two species differ markedly ( Figs. 164, 172).

Description. Size: holotype (length/width, mm): body (length to elytral apices) 2.06/1.02; head width 0.58; pronotum 0.44/0.83, PA 0.66, PB 0.63; elytra 1.45/1.02. Size range 1.91–2.24 mm. Dorsum, venter and legs reddish 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, rounded granules, each granule with short seta.

Pronotal disc with contiguous or nearly contiguous circular or oval 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 7/8, second arcuate and continiuing to apices, third terminating at ca. posterior 3/4. 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 slightly irregular rows of punctures.

Mentum densely pubescent; postmentum sparsely pubescent, shining. Genae microreticulate, dull, without posterior ridge. Mesoventrite with very low tubercle on intercoxal process. Metaventrite virtually non-pubescent; disc almost flat, very finely microreticulate, shining, with narrow, oval, deep midlongitudinal depression in posterior 1/2; lateral areas dull, very finely microreticulate. 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. "Small red mouse," named in reference to the body color and the mouse-like shape of the distal part of the aedeagus, in lateral view.