Menomadraena ivohibe, Perkins, 2017

Perkins, Philip D., 2017, Hydraenidae of Madagascar (Insecta: Coleoptera), Zootaxa 4342 (1), pp. 1-264 : 179-180

Menomadraena ivohibe , new species

Figs. 170 (habitus), 172 (aedeagus), 299 (map)

Type Material. Holotype (male): Fianarantsoa, R.S. Ivohibe, 8.0 km E Ivohibe, camp II, sifted litter (leaf mold, rotten wood) montane rainforest, elev. 1200 m, 22° 29' S, 46° 58.1' E, 15–21 x 1997, B. L. Fisher (1747) ( FMNH). Paratypes: Same data as holotype (3 FMNH).

Differential Diagnosis. Similar in color (reddish brown) and habitus to M. nitedula ; differing therefrom in smaller size (ca. 1.85 vs. 2.00 mm), having less strongly arcuate lateral margins of the pronotum, and having a longer 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) 1.85/0.88; head width 0.53; pronotum 0.40/0.72, PA 0.59, PB 0.62; elytra 1.23/0.88. Size range ca. 1.85–1.94 mm. Dorsum and venter reddish brown, legs brown.

Maxillary palpi short, last palpomere distinctly shorter than first antennomere. Last antennomere longer and wider 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 or slightly oval granules, each granule with short recumbent seta at posterior margin; 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) and third terminating at ca. posterior ¾, second arcuate and continiuing to apices. 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, most punctures also with a minute granule on each side, very inconspicuous. 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 almost flat and weakly shining, with midlongitudinal sulcus in posterior 1/2; lateral areas dull, very finely microreticulate ( Fig. 170). 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. Named in reference to the type locality.