Mecyclothorax najtae Deuve, 1987

Liebherr, James K., 2018, Cladistic classification of Mecyclothorax Sharp (Coleoptera, Carabidae, Moriomorphini) and taxonomic revision of the New Caledonian subgenus Phacothorax Jeannel, Deutsche Entomologische Zeitschrift 65 (1), pp. 1-63 : 32-33

10. Mecyclothorax najtae Deuve Figures 16E , 19

Mecyclothorax najtae Deuve 1987: 144.

Diagnosis.

This, the second of the small-bodied species with very obtuse pronotal hind angles and basally straight lateral pronotal margins (Fig. 16D-E ) can be diagnosed by the unique elytral configuration with elytral length only slightly greater than breadth: MEW/EL = 0.96. This species is also characterized by extremely convex eyes, with the eye convexity ratio, EyL/EyD = 2.0. Standardized body length 3.7 mm. Chaetotaxy +/+//+/-//+/2/+/+.

Description

(n = 1). As a complement to Deuve’s (1987) description, we may add: 14 ommatidia along horizontal diameter of eye; ligular apex rounded, the two ligular setae separated by two setal diameters; paraglossae thin, extended beyond ligular margin 1/2 distance from their base to ligular margin; antennae moderately elongate, antennomere 9 length 2.25 × maximal breadth. Pronotum transverse, hind angles very obtuse, the lateral margins only slightly concave anterad angles (Fig. 16E ); MPW/BPW = 2.0, MPW/PL = 1.32; front angles only slightly protruded, broadly obtuse, pronotal apex and base subequal, APW/BPW = 1.05; proepisternum separated anteriorly from prosternum by fine shallow groove, distinctly separated ventrally by deep, indistinctly punctate groove; prosternal process deeply depressed between procoxae, that depression extended 1/2 distance toward anterior prothoracic margin. Abdomen with deep crescent-shaped depression along suture between first and second ventrite, second ventrite depressed within crescent; suture between second and third ventrites reduced, incomplete laterally; ventrites 2-6 with broad, shallow, linear plaques near lateral margin. Microsculpture of frons and vertex a shallow transversely stretched isodiametric mesh; pronotal disc covered with elongate transverse mesh, sculpticell breadth 2-3 × length, surface subiridescent, sculpticells on median base and in laterobasal depressions less transverse, breadth 2 × length; elytra iridescent, disc with dense transverse lines loosely connected into a mesh, apex covered with transverse lines.

Type - Holotype female (MNHN): HOLOTYPE (red label) // Nouvelle-Caledonie / Menazi 1020 m / 18.x84 Tillier ”/” Bouchet // Mecyclothorax / Mecyclothorax najtae sp. n. / det. T. Deuve // New Caledonia Mecyclothorax revision / measured specimen 1 / J.K. Liebherr 2016. The specimen is mounted on two platens: 1, head, prothorax, and pterothorax separated from elytra; 2, abdominal ventrites. No female genitalic structures were available for study in this specimen.

Distribution and habitat.

The type locality northwest of the summit of Menazi (Fig. 19 ) is situated at 21°26.83'S × 165°41.75'E. Deuve (1987) reported the microhabitat as humid Auracaria forest on peridotite; i.e. igneous, ultramafic rock.

Figures

Figure 16. New Caledonian Mecyclothorax (Phacothorax) spp., dorsal view: A, M. plurisetosus; B, M. megalovatulus; C, M. octavius; D, M. laterovatulus; E, M. najtae.

Figure 19. Geographical distributions of Mecyclothorax (Phacothorax) spp.