Mecyclothorax parapicalis, 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 : 128-131

Taxon classification Animalia Coleoptera Carabidae

(050) Mecyclothorax parapicalis sp. n. Figs 61I, 65D, 67

Diagnosis.

Like Mecyclothorax apicalis , but the body is broader at the elytral base, and the elytral lateral margins are slightly extended laterally behind the humeri, the humeral angle defined by a slight hitch at the base of the moderately broad lateral marginal depression (Fig. 65D). The microsculpture on the forebody is more transverse, with: 1, a shallow transverse mesh, sculpticell breadth 2 –3× length on the vertex; 2, transverse mesh, sculpticell breadth 3 × length, to transverse lines on the pronotal disc; and 3, evident isodiametric and transverse sculpticells over the pronotal median base. The male aedeagal median lobe exhibits a rhomboidal apex, with the apical and ventral margins meeting at an acute angle (Fig. 61I).

Setal formula 2 1 2 0. Standardized body length-3.8-3.9 mm-is slightly smaller than that of Mecyclothorax apicalis ; length 4.0-4.2 for that species.

Description

(n = 3). Head capsule with frontal grooves broad near clypeus, a broad lateral carina to anterior supraorbital seta; dorsal surface of neck flat to slightly concave; eyes moderately convex but covering much of ocular lobe, ocular ratio = 1.41-1.46, ocular lobe ratio = 0.82-0.84; labral anterior margin medially emarginate 1/6 of length; antennae submoniliform, antennomeres 2-3 with sparse pelage of short setae; mentum tooth with sides acute, apex tightly rounded. Pronotum transverse, MPW/PL = 1.28-1.36, broad basally, MPW/BPW = 1.41-1.45; hind angle slightly obtuse, margin rounded behind or not, lateral margin subparallel or slightly divergent immediately anterad angle; median base slightly depressed relative to disc, smoother medially, laterally punctate, longitudinal wrinkles lining juncture with disc; basal margin broadly, slightly convex between laterobasal depressions; median longitudinal impression very shallow, finely incised; anterior transverse impression deep, finely incised, shallower at midline; anterior callosity slightly convex, smooth, glossy; front angles slightly produced, tightly rounded; pronotal apical width slightly narrower than basal width, APW/BPW = 0.93-0.97; lateral marginal depression narrow throughout, edge beaded except where slightly broader at front angles; laterobasal depression broadly convex between median base and hind angle. Proepisternum with 5 minute punctures along hind marginal groove; prosternal process with narrow median impression, margins beaded between coxae. Elytra subquadrate, disc flat, sides distinctly sloped; basal groove distinctly recurved inside humeral angle; elytra broadest behind midlength and humeri extended laterally in concert with broad pronotal base, MEW/HuW = 1.95-2.0; parascutellar seta present; parascutellar striole with 5 punctures, shallow but continuous between punctures; sutural interval flat in basal half, progressively elevated along suture to apex; sutural and 2nd striae of subequal depth from base to apex; discal striae 1-4 smooth, shallow, striae 5-6 shallower, traceable, stria 7 absent; discal elytral intervals 2-6 only slightly convex to nearly flat on lateral intervals; 8th interval slightly more convex than apical fused portion of striae 5 + 7; 2 dorsal elytral setae at 0.32 × and 0.67 × elytral length, setal impressions small, spanning ½ width of interval 3; apical and subapical setae absent; lateral elytral setae arranged in anterior series of 7 setae and posterior series of 6 setae; elytral marginal depression of moderate breadth at humerus, narrowed laterad posterior setal series, margin upturned except beaded at subapical sinuation; subapical sinuation shallow, more abruptly incurved anteriorly. Mesepisternum with ~6 punctures in 1-2 rows; metepisternal width to length ratio = 0.75; metepisternum/metepimeron suture distinct. Abdomen with irregular lateral wrinkles on ventrites 1-5, and lateral depressions on ventrites 3-6; suture between ventrites 2 and 3 reduced laterally, effaced; apical male ventrite with 2 marginal 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, shallow, median area broad. Microsculpture of elytral disc consisting of distinct isodiametric and transverse sculpticells arranged in a mesh, elytral apex with transverse mesh, sculpticell breadth 2 × length; metasternum with distinct transverse mesh; laterobasal abdominal ventrites with swirling isodiametric and transverse microsculpture. Coloration of vertex rufobrunneous; antennomeres 1-3 rufoflavous, 4-11 darker, brunneous; pronotal disc rufobrunneous with piceous cast, lateral margins, base, and apex narrowly rufobrunneous; proepipleuron rufoflavous, proepisternum rufobrunneous; elytral disc rufobrunneous with slightly metallic reflection, sutural interval concolorous basally, rufoflavous apically; intervals 7-8 inside humeral angle plus lateral marginal depression rufoflavous; elytral apex contrastedly flavous from apical terminus of interval 4; elytral epipleuron dorsally rufoflavous, ventrally rufobrunneous, metepisternum rufobrunneous; abdomen with ventrites 1-6 medially rufopiceous, ventrites 3-6 laterally rufoflavous, abdominal apical ventrite with apical 1/6 paler, flavous; metafemur flavous; metatibia flavous with brunneous cast.

Male genitalia (n = 1). Aedeagal median lobe robust, distance between parameral articulation and tip 3.8 × depth at midlength (Fig. 61I); apex trapezoidal, with flat apical face and angled ventral margin meeting at tightly rounded tip; internal sac with diffusely developed dorsal ostial microtrichial patch, flagellar plate short, length 0.3 × parameral articulation-tip distance.

Holotype.

Male (BPBM) labeled: HAWAII: E. Maui I: / Haleakala Nat. Park / Haleakala Crater / 2134 m 1.VIII.1973 / Deschampsia nubigena / W.C. Gagné Coll. / BISHOP Museum // Mecyclothorax / parapicalis / ♂ photo / det. J.K. Liebherr 2014 // HOLOTYPE / Mecyclothorax / parapicalus / Liebherr / det. J.K. Liebherr 2015 (black-margined red label).

Paratypes.

Same data as holotype (BPBM, 1; CUIC, 1)

Etymology.

The similarity of this species to Mecyclothorax apicalis makes the species epithet parapicalis appropriate; the adjectival epithet meaning like apicalis

Distribution and habitat.

The distribution of Mecyclothorax parapicalis is completing subsumed by that of the very similar appearing species Mecyclothorax apicalis (Fig. 67). This species is known only from three specimens collected by Dr. Wayne Gagné in association with Deschampsia nubigena (hairgrass) in the vicinity of Holua Cabin. The specimens were collected during August, whereas all specimens of the closely related Mecyclothorax apicalis have been collected in March, April, June, July, and October.