Mecyclothorax affinis, 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 : 51-53

Taxon classification Animalia Coleoptera Carabidae

(017) Mecyclothorax affinis sp. n. Figs 28B, 29D, 32

Diagnosis.

Like Mecyclothorax aeneipennis in the quadrate elytra with broad humeri-MEW/HuW = 1.76-but with cordate pronotum, the lateral margins slightly convergent anterad the projected, right hind angles (Fig. 28B). The eyes are relatively flat, ocular ratio = 1.35, and the ocular lobes project abruptly from the gena; a slotlike impression at the juncture of gena and ocular lobe. The single specimen, which does not appear teneral, has the pronotal and elytral lateral marginal depressions paler than the discs, the pronotal margins rufobrunneous versus the rufopiceous disc, and the elytral marginal depression narrowly rufoflavous versus the rufopiceous disc. Moreover, this is the only Haleakalā species in the group to be characterized by absence of the parascutellar seta. Setal formula 2 2 2 2. Standardized body length 4.5 mm.

Description

(n = 1). Head capsule with frontal grooves broad near clypeus, a lateral carina to anterior supraorbital seta, dorsal surface of neck slightly concave; labral anterior margin broadly, shallowly emarginate; antennae filiform, antennomeres 2-3 with sparse pelage of short setae; mentum tooth with sides acute, apex tightly rounded. Pronotum moderately transverse, MPW/PL = 1.30, base moderately constricted, MPW/BPW = 1.38; median base depressed relative to disc, surface strigose with fine longitudinal wrinkles; basal margin slightly convex between the laterobasal depressions; median longitudinal impression shallow, very finely incised at depth, joined by irregular transverse wrinkles; anterior transverse impression deep, finely incised at depth, separate from discal intervals; anterior callosity moderately convex, crossed by shallow wrinkles; front angles slightly projected, apex tightly rounded; APW/BPW = 0.99; lateral marginal depression slightly broader at front angle, moderately narrow behind, edge upturned; laterobasal depression smooth, laterally elevated to projected lateral margin. Proepisternum with smooth marginal groove; prosternal process medially depressed, upraised laterally to narrow bead anterad coxa. Elytra with convex disc, sides progressively sloped laterad; basal groove recurved medially, straight laterally to subangulate humerus; parascutellar striole shallow, with 3-4 punctures; sutural interval flat basally, convex at suture from disc to apex; sutural and 2nd striae of subequal depth from base to apex; intervals 2-5 moderately convex, associated striae with minute punctulae causing strial irregularities, all striae smooth and deep apically; 7th and 8th intervals of similar convexity mesad subapical sinuation; 2 dorsal elytral setae at 0.25 × and 0.61 –0.63× elytral length, setal impressions extended over 2/3 of interval 3; both apical and subapical setae present; lateral elytral setae arranged as an anterior series of 7 setae and a posterior series of 6 setae; elytral marginal depression moderately broad throughout length until reduced to beadlike margin from subapical sinuation to apex; subapical sinuation shallow, more abruptly incurved anteriorly. Mesepisternum with ~8-9 punctures in 2-3 rows; metepisternal width to length ratio = 0.83. Abdomen with irregular lateral wrinkles on abdominal ventrites 1-5; suture between ventrites 2 and 3 complete; apical ventrite of male with 2 marginal setae. Legs-metatarsomere 1/metatibial length ratio = 0.20, metatarsomere 4 length along outer lobe 1.2 × medial tarsomere length, apical and subapical setae present; metatarsal dorsolateral sulci very broad, median area rough to carinate. Microsculpture of vertex isodiametric to slightly transversely stretched in rows; pronotal disc with transverse mesh, sculpticell breadth 2 –3× length; pronotal median base with isodiametric to transverse mesh; elytral disc with transverse mesh, sculpticell breadth 3 × length, to transverse lines; elytral apex with shiny transverse mesh, sculpticell breadth 2 –3× length; metasternum with distinct transverse mesh; laterobasal abdominal ventrites with swirling isodiametric and transverse microsculpture. Coloration of vertex rufobrunneous; antennomere 1 flavous, antennomeres 2-3 rufoflavous, 4-11 rufobrunneous; pronotal disc rufopiceous; pronotal margins rufobrunneous in depression, lateral bead darker, rufopiceous; proepipleuron rufoflavous, proepisternum dark rufobrunneous; elytral disc rufopiceous; sutural interval basally rufobrunneous, apically rufoflavous to flavous; elytral margins and apex narrowly rufoflavous; elytral epipleuron rufoflavous laterally, rufobrunneous ventrally, metepisternum rufopiceous; abdomen medially rufopiceous, laterally rufobrunneous; abdominal apical ventrite with narrowly paler margin, rufobrunneous; metafemur flavous with piceous cloud on basal 2/3; metatibia rufobrunneous.

Male genitalia (n = 1). Aedeagal median lobe gracile, distance from parameral articulation to tip 4 × median breadth (Fig. 29D), apex elongate, with narrow extension beyond ostial opening and dorsoventrally expanded, spoonlike tip; internal sac without apparent microtrichial patches, moderately elongate flagellar plate visible dorsad parameral articulation in uneverted specimen, flagellar plate length 0.42 × distance from parameral articulation to tip.

Holotype.

Male (BPBM) dissected and labeled: HAWAIIAN ISLANDS / Maui, Haleakala / Waikau Cabin 6400', / VI-18-1975 // R. Burkhart / Collector // ACC. NO. 1990.009 / BISHOP Museum // HOLOTYPE / Mecyclothorax / affinis / Liebherr / det. J.K. Liebherr 2015 (black-margined red label).

Etymology.

The Latin adjective affinis -meaning related to or neighboring-is used for this species to signify its close relationship to Mecyclothorax cognatus , a species named with the Latin word that means kindred or related ( Brown 1956).

Distribution and habitat.

The lone specimen representing this species was collected at Waikau Cabin (Fig. 32) without any associated ecological information.