Mecyclothorax pitohitiensis, Liebherr, James K., 2013

Liebherr, James K., 2013, The Mecyclothorax beetles (Coleoptera, Carabidae, Moriomorphini) of Tahiti, Society Islands, ZooKeys 322, pp. 1-170 : 50-51

36. Mecyclothorax pitohitiensis sp. n.

Diagnosis.

Among species of the Mecyclothorax dannieae group with well-impressed elytral striae and setal formula 2221 (Figs 23, 25 B–D), this species can be diagnosed by the pronotum with explanate lateral margins outside the laterobasal depressions, and the convexly curved basal pronotal margin immediately mesad the basal pronotal seta (Fig. 23C). The elytra are narrowed basally, MEW/HuW = 2.10-2.19 (n = 5), and the humeri are narrowly rounded, with the lateral marginal depression bordered along the elytral margin by an upturned edge. If a male specimen is available, the dramatically expanded aedeagal median lobe apex with acuminate dorsal process (Fig. 24F), will easily diagnose this species. Standardized body length 5.3-5.8 mm. Head with shallow frontal grooves, laterally margined behind by a rounded carina mesad anterior supraorbital seta, fine wrinkles radiating onto frons, groove broad and smooth anteriorly near frontoclypeal suture; eyes moderately protruded, ocular ratio 1.39-1.49, ocular lobe extended from gena at>135° angle, lobe margined behind by broad, shallow groove at gena, ocular lobe ratio 0.75-0.83; antennae elongate, filiform, antennomere 8 length 2.25 × maximal breadth. Pronotum moderately transverse, MPW/PL = 1.23-1.33; median base moderately depressed relative to convex disc, about 16 punctures each side and 5-8 elongate punctures along margin with disc; anterior transverse impression broad, shallow but traceable across breadth, about 6 densely arrayed longitudinal strigae crossing impression each side near midline; frontal angles broadly rounded, protruded, lateral marginal depression broader inside angle, narrower behind with margin most beadlike near lateral pronotal seta, margin progressively broader basally, the sinuous laterobasal depression lined with rounded depressions. Elytra obovate, the humeri narrowed basally, greatest width just posterad midlength; elytral striae 1-6 deep, irregular along length, the irregularities taking the form of crenulations in the strial walls, discal intervals broadly, moderately convex, stria 7 slightly shallower but still irregular along length; eighth interval more convex medially and laterally at elytral apex, bulging ventrally, not upraised dorsally along seventh stria; lateral elytral setae 7 + 6. Metathoracic wings thickened, stenopterous, apex extended beyond hind margin of metanotum, length 2.5 × breadth, apex narrowly rounded; remnants of Sc+R and M veins present. Microsculpture of pronotum well developed, disc covered with transverse mesh, anterior callosity, lateral marginal depressions, and median base between punctures lined with upraised isodiametric mesh; discal elytral intervals covered with well-developed transverse mesh, sculpticell breadth 2 –3× length. Coloration of head dark rufous; antennomeres 1-11 rufoflavous, 4-11 with smoky cast; pronotal disc dark rufous with silvery metallic reflection; elytral disc rufobrunneous with a purplish metallic reflection; femora rufoflavous with brunneous cast, tibiae rufobrunneous.

Male genitalia. Aedeagal median lobe shaft slightly broader at midlength, ventral surface slightly convex (Fig. 24F); apex broadly curved dorsally beyond ostium, the apex expanded both dorsally and ventrally, the ventral expansion angulate at the very broadly curved apical face, the dorsal surface acuminate; ostial canal situated on left face of apex, very near and parallel to the dorsal margin; right paramere expanded apically as a ventrally setose lamellate structure; internal sac narrowly tubular, with broadly distributed ventral ostial microtrichial patch, and smaller dorsal ostial microtrichial patch; flagellar plate short, length 0.30 × distance from parameral articulations to apical face.

Female reproductive tract. Bursa copulatrix broad with rounded apex, length 2.5 × length, cuticle appearing thick based on depth of staining with Chlorazol Black (Fig. 14C); basal gonocoxite 1 quite setose (Fig. 8E), 4-5 setae near apex at medial angle, 4-5 setae along lateral margin of coxite, and unilaterally one seta isolated between; medial surface of gonocoxite 1 lined with about 13 smaller setae; apical gonocoxite 2 robust, broad basolaterally with broadly rounded apex, bearing two broad, parallel-sided lateral ensiform setae and one tapered dorsal ensiform seta; apical sensory furrow bearing two apical nematiform setae and two furrow pegs.

Holotype male (MNHN) labeled: French Polynesia: Tahiti Nui / Pito Hito el. 2000 m 2-VI- / 2006 lot 02 pyrethrin fog / 17°36.790'S, 149°27.842'W / E.M. Claridge // HOLOTYPE / Mecyclothorax / pitohitiensis / J.K. Liebherr 2013 (black-bordered red label).

Allotype female (MNHN): same data as holotype.

Paratypes: Tahiti Nui; Pito Hiti, 2070 m el., 17°36.819'S, 149°27.842'W, 2-vi-2006 lot 01, Claridge, pyrethrin fog (CUIC, 2; EMEC, 3; NMNH, 1); same data as holotype (CUIC, 2; EMEC, 4); 2080 m el., 17°36.806'S, 149°27.842'W, 2-vi-2006 lot 03, Claridge, pyrethrin fog (EMEC, 1).

Etymology.

This species name is derived from the type locality, Piti Hiti, resulting in an adjectival epithet - pitohitiensis - that is derived in parallel with that of the closely related species, Mecyclothorax tahitiensis .

Distribution and habitat.

All specimens representing this species have been collected from 2000-2080 m elevation on Pito Hiti via pyrethrin fogging of moss-covered vegetation.