Mecyclothorax ommatoplax, Liebherr, James K., 2015

Liebherr, James K., 2015, The Mecyclothorax beetles (Coleoptera, Carabidae, Moriomorphini) of Haleakala-, Maui: Keystone of a hyperdiverse Hawaiian radiation, ZooKeys 544, pp. 1-407 : 153-155

Taxon classification Animalia Coleoptera Carabidae

(062) Mecyclothorax ommatoplax sp. n. Figs 81A, 85

Diagnosis.

This species is easily distinguished by the very small, little convex eyes; ocular ratio = 1.29-1.35, ocular lobe ratio = 0.68-0.69, in combination with the granulate isodiametric elytral microsculpture (Fig. 81A). Setal formula 2 2 2 2. Among species of the Mecyclothorax argutor group, the beetles are of moderate size, standardized body length 4.8-5.5 mm.

Description

(n = 2). Head capsule with frontal grooves broad near clypeus, curved laterally near clypeal juncture, a straight ridgelike lateral carina extended from dorsal mandibular articulation to mesad anterior supraorbital seta; dorsal surface of neck flat to slightly convex; compound eye with approximately 12-13 ommatidia across the maximal horizontal diameter; labral anterior margin medially emarginate 0.2 × length; antennae filiform, antennomere 3 with sparse, short setae; mentum tooth with sides acute, apex pointed. Pronotum slightly transverse, MPW/PL = 1.17-1.27, constricted basally, MPW/BPW = 1.51-1.58; hind angle right, apex rounded, lateral margin parallel anterad angle; median base depressed relative to disc, covered with rugose wrinkles and round punctures; basal margin broadly, medially extended between laterobasal depressions; median longitudinal impression fine, shallow, crossed by shallow wrin kles; anterior transverse impression broad, shallow, crossed by longitudinal wrinkles; anterior callosity slightly convex, crossed by longitudinal wrinkles from anterior impression; front angles not projected, rounded; pronotal anterior width slightly greater than basal width, APW/BPW = 1.02-1.05; lateral marginal depression narrow, margin upturned to beaded; laterobasal depression moderately broad with low oblique ridge terminated at hind angle. Proepisternum with 6 punctures along hind marginal groove; prosternal process medially concave, margin smoothly upraised. Elytra subquadrate, narrow basally, the basal groove meeting lateral marginal depression at subangulate humerus, MEW/HuW = 1.81-1.94; disc flat, sides moderately depressed; parascutellar seta present; parascutellar striole shallow, smooth, continued onto base; sutural interval slightly more convex than lateral intervals; sutural and 2nd striae of subequal depth from base to apex; discal striae 1-5 continuous, slightly irregular but impunctate, deeper and smooth apically, stria 6 reduced, stria 7 traceable, very shallow, associated intervals broadly, slightly convex; 8th interval slightly convex laterad 7th stria, principally due to deep apical portion of 7th stria; 2 dorsal elytral setae at 0.30 × and 0.59 –0.60× elytral length, setal impressions shallow, about breadth of interval 3; apical and subapical setae present; lateral elytral setae arranged as anterior series of 7 setae and posterior series of 6 setae; elytral marginal depression moderately broad, lined with sculpticells, the margin upturned; subapical sinuation evident, abrupt and brief. Mesepisternum with ~14 punctures in 2-3 rows, metepisternal width to length ratio = 0.67; metepisternum/metepimeron suture distinct. Abdomen with shallow indistinct wrinkles on ventrites 1-3, suture between ventrites 2 and 3 complete; apical female ventrite with 4 equally spaced setae and median trapezoid of 4(-5 unilaterally) subequal, short setae. Legs-metatarsomere 1/metatibial length ratio = 0.19; metatarsomere 4 length along outer lobe 1.4 × medial tarsomere length, with apical and subapical setae; metatarsal dorsolateral sulci broad, shallow. Microsculpture of vertex an upraised isodiametric mesh in transverse rows; pronotal disc with transverse mesh, median base with granulate isodiametric mesh; elytral apex with distinct transverse mesh; metasternum with distinct transverse mesh; laterobasal abdominal ventrites with swirling isodiametric and transverse microsculpture. Coloration of vertex rufobrunneous; antennomere 1 flavous, 2-11 rufoflavous; pronotal disc rufobrunneous, lateral margins narrowly paler in lateral depression, rufoflavous; proepipleuron rufoflavous, proepisternum rufobrunneous with piceous cast; elytral disc reflective rufobrunneous, sutural interval basally rufous, apically flavous, elytral margins broadly rufoflavous, apex broadly rufoflavous to flavous; elytral epipleuron flavous, metepisternum rufobrunneous with piceous cast; abdomen rufobrunneous with piceous cast, apical half of ventrite 6 broadly paler, flavous; metafemur flavous; metatibia rufoflavous.

Female reproductive tract. The holotype and paratype females were not dissected.

Holotype.

Female (CUIC) labeled: HI:Maui Haleakala N.P. / Kipahulu Vy.1500 m el. / 9-V-1991 sifting / leaf litter by day // S. Jessel / A.C. Medeiros, / Jr. collectors // Mecyclothorax / ommatoplax / ♀ photo / det. J.K. Liebherr 2014 // HOLOTYPE / Mecyclothorax / ommatoplax / Liebherr / det. J.K. Liebherr 2015 (black-margined red label).

Paratype.

HI: Maui, Kipahulu Vy., West Camp at Dead Pig Bog, 2010 m el., 18-iii-1998, Takumi (BPBM, 1).

Etymology.

The species epithet compounds the Greek words plax, flat round plate, and ommatos, the genitive of omma, i.e. eye. As Greek, ommatoplax is treated as a noun. The epithet refers to the very flat eyes characteristic of this species.

Distribution and habitat.

Mecyclothorax ommatoplax is distributed in the upper reaches of Kīpahulu Valley (Fig. 85). Specimens have been collected in sift samples of leaf and humus litter.