Mecyclothorax waikamoi, 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 : 42-45

Taxon classification Animalia Coleoptera Carabidae

(013) Mecyclothorax waikamoi sp. n. Figs 23C, 24B, 25, 26A, 27A

Diagnosis.

This is the first of three very similar species, all characterized by small body size-standardized body length in this species = 2.9-3.4 mm-and subovoid elytra with variously punctate discal striae (Fig. 24 B–D). The three species are all of dark coloration, with rufobrunneous head capsules, rufopiceous pronotal discs, and piceous elytral discs with narrowly paler, rufoflavous to flavous margins. Mecyclothorax waikamoi deviates from the other two in the well-developed punctation of elytral striae 1-6 in the basal half of the elytra (Fig. 24B). The eyes also tend to be less convex in this species-ocular ratio = 1.38-1.47-though that span overlaps the range of ocular ratios of the other two species at 1.43-1.51. The male aedeagus (Fig. 26A) can diagnose the species, with males of this species (Fig. 26A) exhibiting a broader, more apically flattened apex to the median lobe. Setal formula 2 1 2 0.

Description

(n = 5). Head capsule with frontal grooves broad near clypeus, a lateral carina to anterior supraorbital seta; dorsal impression of neck flat to slightly concave; labral anterior margin broadly, shallowly emarginate; antennae submoniliform, antennomere 2 sparsely setose, antennomere 3 with well-developed pelage of short setae; mentum tooth with sides acute, apex rounded. Pronotum broad, MPW/PL = 1.28-1.34, basally constricted, MPW/BPW = 1.47-1.54, with sinuate lateral margins anterad slightly obtuse hind angles (obtuse due to rounded basal margin inside angle); median base moderately depressed, sparsely punctate, shallow wrinkles at juncture with disc; basal margin broadly, slightly convex between laterobasal depressions; median longitudinal impression extremely shallow, narrowly incised; anterior transverse impression shallow, narrow, discontinuous medially; anterior callosity slightly convex, smooth; front angles slightly projected, rounded; distance between front and hind angles subequal, APW/BPW = 0.97-1.05; lateral marginal depression narrow, edge not upraised from front angle to lateral seta, very narrow and beadlike in basal half; laterobasal depression smooth, narrow, continuous with lateral depression. Proepisternum with ~5 minute punctures along hind marginal groove; prosternal process medially depressed, sides broadly upraised. Elytra subovoid and convex, sides and apex depressed relative to disc; basal groove evenly recurved to tightly rounded humeral angle; MEW/HuW = 1.95-2.03; parascutellar seta present; parascutellar striole with 3 punctures, discontinuous between punctures; sutural interval more convex than lateral intervals, sutural juncture elevated; sutural and 2nd striae of subequal depth and punctation from base to apex; striae 1-6 and 8 complete, stria 7 shallower, associated intervals convex; 7th and 8th interval of similar convexity mesad subapical sinuation; 2 dorsal elytral setae at 0.33 × and 0.50 × elytral length, setal impression small, spanning about half of interval 3; both apical and subapical setae absent; lateral elytral setae arranged as anterior series of 7(6) setae, and a posterior series of 5(4) setae; elytral marginal depression slightly broader at humerus, narrowed laterally to a beadlike margin at subapical sinuation; subapical sinuation very shallow, more abruptly incurved anteriorly. Metepisternum with ~5 very shallow punctures in 1 row; metepisternal width to length ratio = 0.84; metepisternum/metepimeron suture distinct. Abdomen with irregular lateral wrinkles on ventrites 1-5; suture between ventrites 2 and 3 complete; apical male ventrite with 2 marginal setae, female apical ventrite with 4 equally spaced marginal setae and a median trapezoid of 4-6 short setae. Legs-metatarsomere 1/metatibial length ratio = 0.18; 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 an obsolete transverse mesh, sculpticell breadth 2 –3× length; pronotal disc with obsolete transverse mesh, sculpticell breadth 3 × length, surface glossy; pronotal median base glossy with obsolete transverse sculpticells; elytral disc with shallow transverse mesh, sculpticell breadth 2 –3× length, transverse lines present on lateral reaches of elytra; elytral apex with transverse sculpticells, breadth 2 –3× length; metasternum with dis tinct transverse mesh; laterobasal abdominal ventrites with swirling isodiametric and transverse microsculpture. Coloration of vertex glossy rufobrunneous to rufopiceous; antennomeres 1-3 flavous, 4-11 rufobrunneous; pronotal disc rufobrunneous, lateral margins and base slightly paler, rufous; proepipleuron flavous, proepisternum rufoflavous to rufobrunneous; elytral disc rufopiceous on intervals 2-9, sutural interval rufoflavous from base, flavous apically; elytral marginal depression narrowly flavous, apex and intervals 8-9 near apex flavous; elytral epipleuron flavous dorsally, rufoflavous along ventral margin, metepisternum rufobrunneous; abdomen with ventrites 1-3 medially rufopiceous, ventrites 4-6 rufobrunneous, apical 1/3 of apical ventrite 6 flavous; metafemur flavous, basal half with brunneous to piceous cloud on anterior surface; metatibia rufoflavous with brunneous cast.

Male genitalia (n = 3). Aedeagal median lobe distinctly curved dorsally, robust, distance from parameral articulation to tip 2.7 × maximum breadth dorsad ostial opening (Fig. 26A); dorsal surface expanded at midpoint of ostial opening, apex downturned with apical face flat; internal sac unornamented, lightly spiculated, flagellar plate moderately elongate, length of sclerotized ventral face 0.43 × distance from parameral articulation to apex.

Female reproductive tract (n = 1). Bursa copulatrix a very short, broad pouch, length 0.17 mm, breadth at base 0.25 mm (Fig. 23C); bursal walls thin, transparent, not wrinkled; gonocoxite 1 with 3 apical fringe setae (Fig. 27A), 4 smaller setae on medial surface; gonocoxite 2 subtriangular, apex pointed, base little extended laterally, 2 short lateral ensiform setae, the apical seta distinctly broader, apical nematiform setae on medial surface at 0.70 × gonocoxite length.

Holotype.

Male (BPBM) dissected, platen mounted and labeled: ♂ (glued to mounting platen) // Waikamoi, Maui / 4000', VII-1956 // R. Namba / Collector // Mecyclothorax / waikamoi / ♂ #5 / det. J.K. Liebherr 2014 // HOLOTYPE / Mecyclothorax / waikamoi / Liebherr / det. J.K. Liebherr 2015 (black-margined red label).

Allotype.

Female (CUIC) labeled: HI:Maui Haleakala / Waikamoi N.C.P. Ukulele / Pipeline 7-V-1998 lot05 / 1550 m el. pyrethrum fog / mossy ohia J.K. Liebherr // 4 // Mecyclothorax / waikamoi / ♀ photo // ALLOTYPE / (same labeling as Holotype).

Paratypes.

HI: Maui: Koolau For. Res., Kula Pipeline Rd., pyrethrin fog log, 1305 m el., 18-v-2003 lot 09, Polhemus (NMNH, 3), pyrethrin fog Metrosideros , 1265 m el., 18-v-2003 lot 08, Polhemus (NMNH, 2); Waikamoi N.C.P., Honomanu drainage transect 3, sift litter, 1700 m el., 10-iv-1991 lot 01, Liebherr (CUIC, 1) scraping Metrosideros humus/moss, 1700 m el., 08-v-1991 lot 03, Liebherr (CUIC, 1).

Etymology.

The species epithet waikamoi is taken from the Hawaiian Waikamoi, the name of the Maui land section and stream that is translated from Hawaiian as "water of the ruler’s taro ( Pukui et al. 1974)."

Distribution and habitat.

Mecyclothorax waikamoi is a species of ‘Ōhi‘a Montane Mesic to Wet Forest from 1200-1700 m elevation in the Waikamoi and Honomanu drainages (Fig. 25). It has been found in ground litter and in mossy humus on the trunks, and in the crotches of ‘ōhi‘a trees.