Mecyclothorax paahonu, Liebherr, James K., 2013

Liebherr, James K., 2013, The Mecyclothorax beetles (Coleoptera, Carabidae, Moriomorphini) of Tahiti, Society Islands, ZooKeys 322, pp. 1-170 : 69-70

57. Mecyclothorax paahonu sp. n.

Diagnosis.

Among the Mecyclothorax viridis group species, this is the only one to share the 2211 setal formula with Mecyclothorax castaneus , but differing from that species in coloration, with the elytral margins - lateral marginal depression and ninth interval - rufoflavously contrasted to each rufopiceous elytral disc. The rufopiceous disc of each elytron is isolated by the rufoflavous sutural interval (Fig. 31E). The elytral base is paler than the pronotal disc, rufobrunneous versus rufopiceous, and the lateral margins of the pronotum are subparallel for a greater distance anterad the right hind angles (Figs 31D versus E). Standardized body length 4.2 mm. Head with frontal grooves narrow posteriorly, linear, curved mesally inside broad convexity near frontoclypeal suture; eyes moderately convex, ocular ratio 1.48, ocular lobe hind margin quite obtuse to genal margin, ocular lobe ratio 0.75; antennae short, segments moniliform, antennomere 8 length 1.56 × maximal breadth. Pronotum little transverse, MPW/PL = 1.17, base moderately broad, MPW/BPW = 1.47; median base slightly depressed relative to disc, rugosely wrinkled laterally, ~7 elongate punctures along margin with disc; anterior transverse impression broad, shallow, crossed by 8-10 finely inscribed, indistinct longitudinal wrinkles that extend across anterior callosity to anterior margin; front angles tightly rounded, very slightly protruded; lateral marginal depression very narrow, edge beaded, depression slightly wider inside front angles; laterobasal depression a broadened sinuate extension of lateral depression, crossed by transverse raised bars, basally defining a triangular raised area bearing basal seta articulatory socket. Elytra narrowly ovate, lateral margins rounded posterad from subangulate humeri; elytral striae 1-6 shallow, with fine irregular elongate punctures that little expand striae, stria 7 shallower, irregularly impressed along length but not punctate; striae 1+ 2, and 3-6 continuously impressed to elytral basal groove; interval 8 more broadly convex laterally near elytral apex than interval 7, but not upraised above stria 7 more than the inner interval; lateral elytral setae 7 + 6. Microsculpture of head a well-developed transverse mesh composed of transverse and isodiametric sculpticells in transverse rows, the sculpticells more isodiametric and upraised on neck; pronotal disc with shallow transverse mesh, sculpticells breadth 2 –4× length; elytral discal intervals with regular transverse mesh, sculpticell breadth 2 –4× length, with crossconnections absent from some limited areas resulting in transverse lines. Coloration of head uniformly rufobrunneous; antennomere 1 flavous, 2-3 rufoflavous, 4-11 rufobrunneous; pronotum rufopiceous with purplish reflection, lateral margins narrowly and median base broadly rufobrunneous; rufopiceous discs of each elytron with purplish reflection.

Holotype female (MNHN) labeled: French Polynesia: Tahiti Nui / Pito Hito el. 2070 m 2-VI- / 2006 lot 01 pyrethrin fog / 17°36.813'S, 149°27.842'W / E.M. Claridge // HOLOTYPE / Mecyclothorax / paahonu / J.K. Liebherr 2013 (black-bordered red label).

Etymology.

The species epithet paahonu is taken from the Tahitian word for maroon, a rough approximation of the dorsal body coloration of the holotype.

Distribution and habitat.

Known from a pyrethrin fog sample of moss-covered vegetation taken 40 m elevation below the summit of Pito Hiti.