Mecyclothorax mordax, 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 : 28-32

Taxon classification Animalia Coleoptera Carabidae

(006) Mecyclothorax mordax sp. n. Figs 15C, 16 E–F, 19

Diagnosis.

Among the pale-margined species in this group, this species can be diagnosed by the obtuse, rounded pronotal hind angles, the lateral margins only slightly sinuate anterad the hind angles (Fig. 15C). The elytra are subquadrate, with the lateral margins broadly extended posterad the rounded humeri. The pronotal base is smooth, with the median base moderately depressed and sparsely covered with shallow punctures and longitudinal wrinkles. Setal formula 2120. Standardized body length 3.8 mm.

Description

(n = 1). Head capsule with frontal grooves broad at clypeus, a lateral carina present to anterior supraorbital seta; dorsal impression of neck flat to slightly concave; eyes little convex, ocular ratio = 1.37, ocular lobe ratio = 0.77; labral anterior margin with broad, shallow emargination; antennae filiform, antennomere 2 sparsely setose, antennomere 3 with well-developed pelage of short setae; mentum tooth with sides acute, apex rounded. Pronotum with lateral seta present, basal seta absent; pronotal base little constricted, MPW/BPW = 1.42; basal margin straight medially, expanded posterad laterobasal depressions; median longitudinal impression shallow, finely incised; anterior transverse impression deep, narrow, finely incised; anterior callosity slightly convex, glossy but crossed by indistinct wrinkles; front angles moderately projected, tightly rounded; apical and basal angles at subequal separation, APW/BPW = 0.99; lateral marginal depression narrow but edge reflexed anteriorly, broader at midlength, beaded at hind angle; laterobasal depression smooth, concave, continuous with lateral depression. Proepisternum with 5 minute punctures along hind mar ginal groove; prosternal process medially depressed, broadly upraised laterally. Elytra subquadrate, disc moderately convex, sides slightly more sloped; basal groove moderately recurved to meet rounded humeral angle; parascutellar seta present; parascutellar striole with 3-5 punctures, striole shallow between punctures; sutural interval more convex than lateral intervals, sutural juncture elevated; sutural and 2nd striae of subequal depth from base to apex; striae 1-4 distinctly punctate basally, the punctures expanding strial breadth; intervals 2-8 convex to apex; 7th and 8th interval similarly convex mesad subapical sinuation; 2 dorsal elytral setae at 0.29 × and 0.59 × elytral length, setal impressions spanning 3rd interval; apical and subapical setae absent; lateral elytral setae arranged as anterior series of 7 setae, and posterior series of 5-6 setae; elytral marginal depression narrow at humerus, posteriorly expanded laterally, broad to midlength, a narrow bead at subapical sinuation; subapical sinuation very shallow, nearly obsolete. Mesepisternum with ~8 shallow punctures arranged in 2-3 rows; metepisternal width to length ratio = 0.80; metepisternum/metepimeron suture distinct; metathoracic flight wing extended to posterior margin of metanotum. Abdomen with irregular lateral wrinkles on ventrites 1-4; suture between ventrites 2 and 3 complete; apical ventrite of male with 2 apical setae. Legs-metatarsomere 1/metatibial length ratio = 0.19; metatarsomere 4 length along outer lobe 1.33 × medial tarsomere length, apical and subapical setae present; metatarsal dorsolateral sulci narrow, lateral, median area broad. Microsculpture of vertex shallow transverse mesh, sculpticell breadth 2 × length; pronotal disc with shallow transverse mesh, sculpticell breadth 2 × length; pronotal median base with shallow isodiametric and transverse-mesh microsculpture; elytral disc with shallow transverse mesh, sculpticell breadth 2 × length; elytral apex with shallow transverse mesh, sculpticell breadth 2 –3× length, plus transverse lines; metasternum with distinct transverse mesh; laterobasal abdominal ventrites with swirling isodiametric and transverse microsculpture. Coloration of vertex a glossy rufopiceous, antennomere 1 rufoflavous, antennomeres 2-3 rufoflavous, 4-11 rufobrunneous; pronotal disc rufopiceous, pronotal anterior callosity, lateral margins, and median base rufoflavous; proepipleuron flavous, proepisternum rufobrunneous with piceous cast; elytral disc with intervals 2-5 piceous from base to near apex, interval 6 rufous, and 7-9 flavous continuous with broadly flavous apex; sutural interval rufoflavous basally, flavous in apical 1/3; elytral epipleuron pale creamy ivory, metepisternum rufopiceous with piceous cast; abdominal ventrites 1-3 medially, and 4-6 mediobasally piceous, flavous laterally and apically; apical 2/3 of apical abdominal ventrite 6 flavous; metafemur flavous with piceous cloud covering basal half of anterior face; metatibia rufoflavous with brunneous cast.

Male genitalia (n = 1). Aedeagal median lobe robust (Fig. 16E), but thinner than that of Mecyclothorax notobscuricornis (Fig. 16C), distance from parameral articulation to tip 3.6 × depth at midlength, apex extended more than its breadth beyond ostial opening, tip tightly rounded; median lobe narrowed apically and curved to the right in ventral view, tip appearing bluntly rounded (Fig. 16F); internal sac with field of 5 large macrospicules, flagellar plate large and visible in uneverted specimen just basad spicular field.

Holotype.

Male (CUIC) dissected and labeled: HI: Maui Haleakala N.P. / Kuiki, below el. 2164 m / N20°42.23', W156°08.00', / 16-V-2001 lot 05 sifting / ohia litter C.P. Ewing // Mecyclothorax / mordax / ♂ #1 / det. J.K. Liebherr 2014 // HOLOTYPE / Mecyclothorax / mordax / Liebherr / det. J.K. Liebherr 2015 (black-margined red label).

Etymology.

The adjectival epithet mordax means biting, corroding, or pungent, an appropriate name for a carabid beetle. But here it is also a play on the epithet daptinus -used by Sharp (1903) for a species of similar appearance-derived from the Greek dapto; to devour, or gnaw ( Brown 1956).

Distribution and habitat.

The lone specimen of this species was found near Kuiki (Fig. 19) in leaf litter taken from below an isolated ‘ōhi‘a tree growing at timberline (e.g. Fig. 5A).