Mecyclothorax tuea, Liebherr, James K., 2013

Liebherr, James K., 2013, The Mecyclothorax beetles (Coleoptera, Carabidae, Moriomorphini) of Tahiti, Society Islands, ZooKeys 322, pp. 1-170 : 81-82

68. Mecyclothorax tuea sp. n.

Diagnosis.

This species is characterized by a narrow pronotum, MPW/PL = 1.14, pronotal lateral margins parallel for 0.10 × pronotal length anterad the slightly obtuse hind angles, and the broadly based elytra, the humeri extended laterally, and the lateral elytral margins distinctly curved posteriorly outside the humeral angles (Fig. 37A). The body surface is distinctly microsculptured, with: 1, the head covered with an upraised transverse mesh on the frons, the sculpticells more isodiametric near pronotum; 2, the pronotal disc with well-developed transverse mesh, sculpticell breadth 2 –3× length, plus the pronotal median base with evident microsculpture among the punctures, the sculpticells a mixture of isodiametric and transverse; and 3, the discal elytral intervals with an upraised transverse mesh, sculpticell breadth 2 × length, the microsculpture associated with a purplish metallic reflection. Setal formula 2121; standardized body length 4.5 mm. Head with broad, shallow frontal grooves, defined laterally by fine carina inside anterior supraorbital seta, irregularly shaped and shallow anteriorly; eyes moderately convex, ocular ratio 1.48, ocular lobes moderately protruded, joined to gena at narrow groove, ocular lobe ratio 0.80; antennae moderately short, submoniliform, antennomere 8 length 1.60 × maximal breadth. Pronotum narrow, median base moderately depressed relative to moderately convex disc, the surface of the median base irregular due to ~9 isolated punctures each side, ~7 short strigae lining margin with disc, and well-developed microsculpture; anterior portion of medial depression and medial portions of anterior transverse impression very broadly and shallowly depressed, the anterior portion of disc appearing flat; lateral reaches of anterior transverse impression not distinct inside protruded, tightly rounded front angles; lateral marginal depression narrow but not deep, margin beaded; a broad shallow oblique depression extended from lateral pronotal seta posteromedially to median base; laterobasal depression irregularly defined by variously raised portions of the lateral and basal margins. Elytra quadrate, the humeri abacoid, MEW/HuW = 1.85; medial surface of disc flat between fourth elytral intervals, though scutellum to sutural interval raised above discal surface; elytral striae 1-6 shallow, distinctly punctate though the punctures are elongate and do not greatly expand strial breadth, stria 7 shallow, irregularly impressed along length, interrupted dorsad posterior series of lateral elytral seta, then deeper and continuous mesad eighth elytral interval that is carinately raised above the stria apicad the elytral subapical sinuation, surface of eighth interval obliquely flattened laterally; lateral elytral setae 7 + 6. Coloration of head and pronotal disc rufopiceous, clypeus and pronotal base and apex rufous, depression inside pronotal front angles rufoflavous; antennomere 1 flavous, 2-3 rufoflavous, 4-11 rufobrunneous; elytral disc rufopiceous with purplish metallic reflection, scutellum and parascutellar striole slightly paler, rufobrunneous, lateral marginal depression narrowly rufoflavous; femora and elytral epipleuron contrastedly rufoflavous, tibiae rufoflavous with base darker, more rufous.

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

Etymology.

The Tahitian word tuea - square, level, fit together - well characterizes the tight fit of the prothorax to the elytra observed in this species.

Distribution and habitat.

The single specimen was collected in a pyrethrin fog sample of moss-covered vegetation at 2070 m elevation on Pito Hiti.