Mecyclothorax krushelnyckyi, 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 : 147-149

Taxon classification Animalia Coleoptera Carabidae

(059) Mecyclothorax krushelnyckyi sp. n. Figs 78B, 79

Diagnosis.

This species (Fig. 78B) can be diagnosed from the other three small-bodied Mecyclothorax ovipennis group species with setal formula 2 2 2 2- Mecyclothorax nubicola (Fig. 78A), Mecyclothorax pusillus (Fig. 78C), and Mecyclothorax rusticus (Fig. 78D)-by: 1, the more narrowly constricted pronotal base; MPW/BPW = 1.54; 2, subellipsoid elytra, with the margin broadly rounded posterad the humerus, and the lateral margins evenly convex laterally; 3, elytra broad relative to forebody, with MEW/MPW = 1.51 and MEW/MHW = 2.15; and 4, the glossy upper body surface with little-developed microsculpture. The vertex is glossy, with obsolete transverse sculpticells, breadth 2 × length in depressions. The pronotal disc is glossy, with obsolete transverse microsculpture visible in angled light; the pronotal base with obsolete transverse microsculpture over portions of the cuticle. The elytral disc is also glossy, with a transverse mesh, sculpticell breadth 2 –3× length, restricted to the lateral and apical areas. Standardized body length 3.95 mm.

Description

(n = 1). Head capsule with frontal grooves broad near clypeus, lateral carina to anterior supraorbital seta; dorsal surface of neck slightly concave; eyes moderately developed, ocular ratio = 1.46, ocular lobe ratio = 0.78; labral anterior margin very shallowly emarginate apically; antennae filiform, antennomeres 2-3 with only 1-2 setae each along shafts; mentum tooth with sides acute, apex rounded. Pronotum transverse, MPW/PL = 1.28; hind angle sharply obtuse, lateral margin subparallel for short distance anterad angle; median base slightly depressed, ~10 punctures each side, punctures more elongate at juncture with disc; basal margin convexly expanded between laterobasal depressions; median longitudinal impression shallow, finely incised; anterior transverse impression deep, finely incised, area behind impression depressed relative to disc; anterior callosity convexly upraised, glossy; front angles slightly projected, rounded; pronotal apical width slightly greater than basal width, APW/BPW = 1.04; lateral marginal depression very narrow, edge appearing beaded except at front angle where margin is slightly broader; laterobasal depression narrow, continuous with lateral depression. Proepisternum with 5 minute punctures along hind marginal groove; prosternal process with narrow median impression, lateral margins broadly beaded between coxae. Elytra with disc flat, sides distinctly sloped; basal groove distinctly recurved to tightly rounded humeri, base relatively broad, MEW/HuW = 1.98; parascutellar seta absent; parascutellar striole with 4 punctures, striole shallow between punctures; sutural interval coplanar with lateral intervals basally, upraised apically; sutural and 2nd striae of subequal depth from base to apex; discal striae 1-5 minutely punctate, the punctures joined by depressed stria medially, striae 4-5 composed of isolated punctures, inner intervals slightly convex, lateral intervals flat; 8th interval slightly more convex than fused apical portion of striae 5 + 7; 2 dorsal elytral setae at 0.24 –0.30× and 0.57 × elytral length, setal impressions moderate, spanning 2/3 of interval 3; apical and subapical setae present; lateral elytral setae arranged in anterior series of 7 setae and posterior series of 6 setae; elytral marginal depression narrow from humerus to midlength, gradually reduced to beadlike margin at subapical sinuation; subapical sinuation shallow, more abruptly incurved anteriorly. Mesepisternum smooth; metepisternal width to length ratio 0.70; metepisternum/metepimeron suture distinct. Abdomen with irregular lateral wrinkles on ventrites 1-5; suture between ventrites 2 and 3 complete; apical female ventrite with 4 equally spaced setae plus a median trapezoid of 4 subequal, short 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 shallow, narrow, median area broad. Microsculpture of metasternum a shallow transverse mesh; laterobasal abdominal ventrites with swirling isodiametric and transverse microsculpture. Coloration of vertex rufobrunneous with piceous cast; antennomeres 1-3 flavous, 4-11 darker, more brunneous; pronotal disc rufopiceous; pronotal lateral margins very narrowly and base and apex rufoflavous; proepipleuron flavous, proepisternum rufopiceous; elytral disc rufopiceous, sutural interval rufous in basal half, rufoflavous in apical half, lateral marginal depression and apex of interval 9 rufoflavous; elytral epipleuron dorsally flavous, ventrally rufoflavous, metepisternum rufopiceous; abdomen with ventral ventrites 1-5 and base of 6 rufopiceous, apical 1/3 of ventrite 6 flavous; metafemur flavous; metatibia flavous, only tibial spines brunneous.

Female reproductive tract. The lone female holotype was not dissected.

Holotype.

Female (UHIM) labeled: HI:Maui I. Haleakala / Kahikinui F.R. 2408 m el. / 20°41.93'N, W156°12.40', W / 24-XI-2008 P. Krushelnycky / Berlese shrubland litter // coll PDJ 627 / spec/lot# PKSP1463 // Mecyclothorax apicalis ? (PDK handwriting) // HOLOTYPE / Mecyclothorax / krushelnyckyi / Liebherr / det. J.K. Liebherr 2015 (black-margined red label).

Etymology.

This species is named to honor Dr. Paul Krushelnycky’s numerous, important discoveries of Mecyclothorax and Blackburnia species in the high elevation habitats of Haleakalā.

Distribution and habitat.

Mecyclothorax krushelnyckyi is one of the few species known to occupy Haleakalā’s south slope (Fig. 79); the others known to do so being Mecyclothorax giffardi (Fig. 56), Mecyclothorax cordithorax (Fig. 89), and Mecyclothorax iteratus (Fig. 106). The single specimen was collected in a sift sample of shrubland litter at 2408 m elevation.