Mecyclothorax menemene, Liebherr, James K., 2012

Liebherr, James K., 2012, The first precinctive Carabidae from Moorea, Society Islands: new Mecyclothorax spp. (Coleoptera) from the summit of Mont Tohiea, ZooKeys 224, pp. 37-80 : 49-51

Mecyclothorax menemene sp. n.

Diagnosis.

This species shares an ovoid, bisetose pronotum, and indistinctly striate elytra with Mecyclothorax jarrigei Perrault, however the striae are even less developed in Mecyclothorax jarrigei , and individuals of that species at 6.2 mm are larger than the unique specimen of this new species; standardized body length 5.2 mm. This species exhibits a setal for mula of 2121 as in Mecyclothorax jarrigei ; setae in the new species include both discal elytral setae and the apical elytral seta positioned just laterad the apex of the second stria. The elytra are exceedingly convex in the unique holotype (Fig. 2C), perhaps due to the slightly teneral nature of the specimen leading to apical distortion of the elytra. The dense transverse microsculpture on the elytra results in a silvery metallic reflection.

Description.

Head capsule frontal grooves smooth, with deepest portions sinuously curved mesad anterior margin of eye, broadest near frontoclypeal suture, and with low rounded carina mesad anterior supraorbital seta; dorsum of head slightly concave between anterior portions of eyes, neck slightly convex; ocular lobe broadly protruded, the posterior portion very obtusely meeting gena at very shallow ot obsolete groove; eyes small, about 16 ommatidia along a horizontal diameter commencing posterad ventral edge of antennal articulatory socket; ocular ratio 1.36, ocular lobe ratio 0.75; labral anterior margin straight; antennomeres 1-3 glabrous except for apical setae; antennae robust, submoniliform, antennomere 8 length 1.9 × greatest width; mentum tooth with sides defining acute angle, apex rounded. Prothorax subovoid, hind angle definable by abrupt change in curvature of pronotal margin, but basolateral margin convex anterad angle, MPW/PL = 1.17 (n = 1); median base slightly depressed relative to disc, ~10 punctures of varying depth each side; basal margin slightly convex between laterobasal depressions; median longitudinal impression obsolete on disc, indicated by darker color of endocarina, present as a narrow elongate depression on front of median base; anterior transverse impression very fine and shallow, obsolete medially, finely incised mesad front angles; anterior callosity narrow, slightly elevated but flat, crossed by irregular longitudinal wrinkles; front angles slightly protruded, rounded, distance between somewhat greater than basal pronotal width, APW/BPW = 1.08; lateral marginal depression very narrow laterally, margin beaded, slightly broader with edge little upturned at front angles, gradually broadened toward laterobasal depression, edge upturned basally; laterobasal depression a broadened continuation of lateral depression, deepest portions mostly smooth but with minute irregularities; proepisternum with ~7 indistinct punctulae along hind margin, proepimeron with minute irregularities along marginal collar; prosternal process broad, slightly depressed mesad anterior margins of procoxal cavities, convex posterad at juncture with posterior face. Elytra subovoid, disc upraised above position of scutellum, MEW/HuW = 2.39; basal groove moderately curved to meet subangulate humerus; parascutellar seta present; parascutellar striole shallow, broadly impressed, smooth; sutural interval slightly elevated at sutural juncture, but not more convex than interval 2 laterally; striae 1-8 of same depth in basal half, shallow but complete, generally smooth but with minute irregularities associated with slight change of direction of deepest portions; at elytral apex, sutural striae 1 and 7 deeply incised, stria 2 shallow, almost discontinuous, striae 3 and 4 shallow but continuous; eighth interval convex apically, the convexity oriented laterally above subapical sinuation; 2 dorsal elytral setae at 0.25 × and 0.60 × elytral length, set in a moderate impression that spans ⅔ width of interval 3; apical elytral seta present, subapical seta absent; lateral elytral setae 7 + 6; elytral marginal depression narrow but margin narrowly u pturned at humerus, depression somewhat broader with more gently upturned edge at midlength, margin becoming less upturned without bead anterad subapical sinuation; subapical sinuation shallow, only slightly changing curvature of apical marginal bead. Mesepisternum punctate anteriorly, ~18 punctures in 2-3 rows; mesepisternum longer than broad, width to length ratio 0.77; metepisternum separated from metepimeron by distinct suture; metathoracic flight wing vestigium apex extended to hind margin of metathorax, venation not assessed. Abdomen with irregular wrinkles laterally on visible ventrites 1-4, indistinct rounded impressions laterally on ventrites 4-6; suture between ventrites 2 and 3 complete laterally. Metatarsomere 4 with emarginate apical margin, overall length including apical lobes 1.4 × median tarsomere length; metatarsomere 4 with short subapical and longer apical setae; metatarsal dorsolateral sulci shallow, lateral, the median surface broadly convex; male metatibia with four rounded projections at bases of four apical setae in mesal longitudinal series. Microsculpture of frons, obsolete, surface glossy, neck with indistinct isodiametric sculpticells in transverse rows; pronotal disc covered with shallow transverse mesh, sculpticell breadth 2 –4× length; pronotal median base with shallow, swirling isodiametric and transverse sculpticells between punctures; elytral disc covered with mixture of well-developed transverse mesh, sculpticell breadth 2 –4× length, and transverse lines; eytral apex with transverse mesh, sculpticells 2 –4× broad as long; metasternum with distinct transverse-mesh microsculpture; laterobasal abdominal ventrites covered with swirling isodiametric and transverse mesh. Coloration of head capsule rufous with piceous cast; antennomeres 1-2 rufoflavous, 3-11 darker, brunneous; pronotal disc rufobrunneous medially, darker than head laterally on disc, lateral marginal depression concolorous, only extreme basal and apical margins paler, rufoflavous; proepipleuron dark rufoflavous, proepisternum rufobrunneous; elytral disc rufobrunneous with silvery reflection, sutural interval concolorous; elytral marginal depression narrowly translucent, slightly paler than disc, apex not paler than more basal portions; elytral epipleuron, metepisternum, and abdominal ventrites concolorous, rufobrunneous; metafemur and metatibia brunneous medially, apices paler, rufoflavous.

MaleGenitalia. (n = 1). Aedeagal median lobe evenly narrowed dorsoventrally from midlength to broadly rounded apex, the apex slightly expanded on ventral margin (Fig. 4D); flagellar plate smaller, length 0.26 × distance from parameral articulation to apex (assessed in uneverted, teneral dissection); internal sac dorsal surface apparently covered with field of fine spicules, neither dorsal nor ventral ostial microtrichial patch apparent; both parameres extended apically about 0.8 × distance from parameral articulation to apex.

Holotype male (MNHN), labeled: French Polynesia: Moorea / Tohiea summit el. 1130 m / 12-IX-2006 lot10 / 17°33.07'S, 149°49.38'W / pyrethrin fog mossy logs / D.A. Polhemus// HOLOTYPE / Mecyclothorax / menemene / J.K. Liebherr 2012.

Etymology.

The species epithet is the Tahitian word menemene, i.e. round or spherical in English (Wahlroos, 2002), denoting the rounded pronotum and broadly rounded, convex elytra of this species. Being indeclinable, the epithet is to be treated as a noun in apposition.

Distribution and habitat.

The unique holotype of this species was collected from a rotten log situated in a deep, wet gulch, in association with four individuals of Mecyclothorax mapo and one of Mecyclothorax popotioaoa .