Mecyclothorax darlingtoni, Liebherr, James K., 2018

Liebherr, James K., 2018, Taxonomic review of Australian Mecyclothorax Sharp (Coleoptera, Carabidae, Moriomorphini) with special emphasis on the M. lophoides (Chaudoir) species complex, Deutsche Entomologische Zeitschrift 65 (2), pp. 177-224 : 177

Mecyclothorax darlingtoni sp. n. Figures 2E, 4A, 7 F–H, 9E, 10E, 11C, 12A, 13A

Mecyclothorax sp. n. D, Liebherr 2018: 3 (non-valid terminal in cladistic analysis).

Diagnosis

(n = 5). This species and M. jameswalkeri are the only species of subgenus Eucyclothorax with glabrous hind pronotal angles (Fig. 2E). Of the two, M. darlingtoni is more broad-bodied (Fig. 4 A–B), with: 1, a more transverse and basally constricted pronotum, MPW/PL = 1.32-1.35, MPW/BPW = 2.21-2.32; and 2, relatively broader elytra, MEW/EL = 0.70-0.75. Both species are characterized by large eyes, but the eyes of M. darlingtoni do not cover as much of the ocular lobe; EyL/OLL = 0.84-0.88. The parascutellar striole in this species is composed of 4-5 small, deep, isolated pits arcuately joining the basal groove. Standardized body length 4.1-4.8 mm. Setal formula ++/+‒/+2++.

Description.

Head capsule broad, vertex broadly convex between deep, sinuous frontal grooves, the grooves more shallowly continued onto clypeus; labrum broadly, moderately concave; mandibles moderately elongate, overall length 1.64 × distance from anterior condyle to lateroapical labral margin; ocular lobes convexly projected, outer eye surface slightly more convex than posterior portion of lobe meeting gena; mentum tooth with sides acute, apex rounded; ligular apex moderately narrowed, 2 ligular setae separated by 2 setal diameters; paraglossae thin, extended 2 × as far past ligular margin as distance from base to ligular margin; mentum breadth/length across lateral lobes = 2.58. Pronotum with articulatory socket of lateral seta touching marginal depression; hind angles obtusely rounded, margin anterad angle slightly concave (Fig. 2E); median base completely margined, the marginal bead uniform and continuous across width (Fig. 4A), base convex anterad basal margin, nearly coplanar with disc though disc is convex and upraised anterad toward middle of pronotum; about 6 minute punctures on base each side of midline, laterobasal depression a shallow longitudinal depression immediately anterad hind angle; median longitudinal impression fine, well indicated, crossed by oblique transverse wrinkles anterad base; anterior transverse impression deep, punctate medially, fine and deep to front angle; anterior callosity slightly convex, defined posteriorly by deep transverse impression; front angle slightly protruded, tightly rounded; prosternal process with broad deep median depression with 4 indistinct pits along its length; prosternum with anteapical groove that is deep and distinctly punctate laterally, smoother and more irregular medially, marginal bead of procoxal cavity bordered anteriorly by distinct, close-set punctures; proepisternum impunctate; proepimeron with broadly raised posterior bead, punctures along suture with proepisternum and anterad posterior bead. Mesepisternum punctate at its deepest portion, about 6 deep punctures in 1-2 dorsoventral rows. Elytra with striae 1-6 composed of isolated punctures in basal half, striae 2-6 reduced to absence in apical 1/3 of length (Fig. 12A), stria 7 absent except near apex from position of subapical sinuation to apical margin; sutural stria deeper in apical half in association with convex sutural interval, the suture smooth from near position of apical dorsal elytral seta to apex (Fig. 12A); stria 8 deep, punctate and bordering lateral marginal depression anteriorly, deeper, smooth and distinct mesad posterior series of lateral elytral setae; lateral elytral setae arrayed in 7 + 6 (anterior series setae and posterior series setae); subapical sinuation evident, abruptly curved anteriorly, but elytral plica covered by margin in dorsal view. Metepisternum moderately elongate, maximum width/lateral length = 0.63; metasternal process with sides acute, apex narrowly rounded, margin very broad medially in apex of process. Abdomen with linear wrinkles on lateral reaches of visible ventrites 1-2, more rounded depressions laterally on ventrites 3-6; suture between ventrites 1 and 2 deeply sinuous laterally; males with 1 seta each side along margin of apical ventrite, females with 2 setae each side and a median patch of 4-5 smaller setae; apical margin of the female apical ventrite with small convex projection medially. Microsculpture absent from frons, the surface glossy, micropunctures visible across the surface; pronotal disc with shallow transverse mesh, sculpticell breadth 3 –4× length, pronotal base with evident, regular transverse mesh, sculpticell breadth 2 –3× length; elytral disc glossy with fine transverse lines, loosely connected into a mesh and producing an iridescent reflection (Fig. 12A), elytral apex with elongate transverse mesh, surface iridescent; metasternum with distinct transverse mesh, sculpticell breadth 2 –3× length; basal abdominal ventrites with swirling transverse mesh and transverse lines, surface iridescent. Coloration of vertex piceous, frons rufous near clypeus, clypeus rufoflavous; antennomeres 1-3 rufoflavous, 4-11 with piceous cast; pronotal disc piceous; margins concolorous; elytral disc dark rufous with iridescent reflection, sutural interval concolorous, interval 9 and marginal depression rufoflavous; elytral apex narrowly brunneous; proepipleuron margin piceous, dark rufous ventrally, proepisternum rufopiceous; elytral epipleura rufoflavous apically, dark rufous ventrally, metepisternum dark rufous; abdominal ventrites rufopiceous with amber posterior margins, apical ventrite with apical half rufobrunneous; femora flavous with brunneous cast; tibiae brunneous with piceous cast.

Male genitalia (n = 4). Male aedeagal median lobe robust, curved, with broad blunt apex, the apical margin curled toward right resulting in a dorsoventral crease (Fig. 7H); internal sac with a robust flagellar sheath, attenuate flagellum, and broad, well-sclerotized dorsal plate (Fig. 7 G–H); right paramere elongate, broader basally, conchoid (Fig. 13A), ventral surface with ~9 setae along margin, dorsal margin with 4 setae; left paramere narrow basally, evenly narrowed to apex.

Female reproductive tract (n = 1). Bursa copulatrix elongate, columnar (Fig. 9E); helminthoid sclerite robust with distal projection; spermathecal duct straight, shorter than spermathecal reservoir, evenly sclerotized; basal gonocoxite with 3-4 setae along apical margin, 2 larger laterally and the balance small and positioned medially (Fig. 10E), an apicomedial seta present; apical gonocoxite subtriangular, apex narrowly rounded; lateral ensiform setae small relative to gonocoxite length; apical nematiform setae in apical sensory furrow.

Types.

Holotype male (MCZ deposited in ANIC): c30 mi.N.of / Brisbane SQ / Mar. '58 / Darlingtons // HOLOTYPE / Mecyclothorax / darlingtoni / J.K. Liebherr 2018 (black-margined red label). Allotypic paratype female (MCZ deposited in ANIC): (same data as holotype, with black-margined red Allotype label).

Paratypes (61 specimens). AUSTRALIA: Queensland: Brisbane, 30 mi. N, iii-1958, Darlingtons (CUIC, 1; MCZ, 19); Mt. Webb, 3 km NE, 15. 03°S 145. 09°E, 03-v-1981, Calder (ANIC, 1); Woondom For. Res., Mothar Mtn. For. Dr., dry rainfor., palm gully, FMHD #2004-217, berl. wet litter along stream, Solidovnikov 1139, 26°15.77'S 152°49.48'E, 380-400 m, 09 –xii– 2004, Solidovnikov (CUIC, 2; FMNH, 24); FMHD #2004-218, berl. litter under palms, Thayer 1139, 26°15.77'S, 152°49.48'E, 09 –xii– 2004, Thayer (CUIC, 3; FMNH, 10); Thayer 1139, pyr. fog old logs, 26°15.77'S, 152°49.48'E, 380-400 m, 09 –xii– 2004, Thayer (FMNH, 1).

Etymology.

The species commemorates Prof. Philip J. Darlington, who collected extensively across Australia during various expeditions undertaken throughout his career. He personally developed the most extensive collection of Australian Carabidae housed in North America, allowing American scientists the ability to work with the fauna. He also curated the Thomas G. Sloane collection after its receipt by C.S.I.R.O., stabilizing the specimens and thereby preserving their information for future researchers. Although he focused on the New Guinea carabid fauna (summarized in Darlington 1971), he rightfully viewed the New Guinean fauna as an extension of the Australian, making biogeographic connections underpinned by taxonomic relationships for much of the Australian Region ( Wallace 1876).

Distribution and habitat.

M. darlingtoni is broadly distributed along the Queensland coast, with recorded localities spanning the vicinity of Brisbane to Mt. Webb in northern Queensland (Fig. 11C). The extensive numbers of specimens collected in Woondom Forest Reserve (FMNH) were extracted from Berlese samples from mesic litter under palms, or from wet litter along a stream. The single specimen from the northerly and, based on present specimens, disjunct Mt. Webb locality is macropterous, as is one of the two specimens from Dalby, whereas all other specimens from southern Queensland are vestigially winged.