Mecyclothorax inconscriptus, 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 : 90-92

Taxon classification Animalia Coleoptera Carabidae

(033) Mecyclothorax inconscriptus sp. n. Figs 45 K–L, 46D, 47D, 50A, 51

Diagnosis.

This is one of the three species in the group with body lengths of 4.1 mm or less, accompanying Mecyclothorax bradycelloides and Mecyclothorax anthracinus in that distinction, however Mecyclothorax inconscriptus (Fig. 50A) incongruently differs from those species by sharing with Mecyclothorax foveolatus and Mecyclothorax interruptus below (Fig. 50 B–D), the state of elytral striae 2-4 fused in association with the dorsal elytral setae. The pronotum is basally constricted, MPW/BPW = 1.49-1.52, versus values of 1.38-1.47 for Mecyclothorax foveolatus and Mecyclothorax interruptus . Pronotal setation also differs from all four species mentioned above in that the basal setae are absent from a slight majority of available specimens, and in the minority of specimens that exhibit the basal setae, they are small and underdeveloped; therefore setal formula 2 1(2) 2 2. Standardized body length 3.7-4.0 mm.

Description

(n = 5). Head capsule with frontal grooves deep near clypeus, straight with lateral carina; dorsal surface of neck convex; ocular lobe obtusely projected from genal surface, eyes little convex, ocular ratio = 1.36-1.44, ocular lobe ratio = 0.72-0.77; labral anterior margin broadly, shallowly emarginate; antennae filiform, antennomere 3 with sparse pelage of short setae; mentum tooth with sides acute, apex tightly rounded. Pronotum transverse, MPW/PL = 1.31-1.37; hind angle obtuse rounded to denticulate, lateral margin straight for short distance to immediately sinuate anterad angle; median base with dense elongate punctures and wrinkles; basal margin nearly straight, slightly convex medially; median longitudinal impression shallow, finely incised, crossed by fine wrinkles; anterior transverse impression shallow, broad, crossed by fine wrinkles; anterior callosity slightly convex, crossed by fine wrinkles; front angles slightly projected, tightly rounded; apical width subequal to slightly larger than basal width, APW/BPW = 1.0-1.04; lateral marginal depression moderate, edge upturned to beaded; laterobasal depression broad, surface wrinkled. Proepisternum with 6 minute punctures along hind marginal groove; prosternal process medially depressed with broad marginal bead. Elytra subquadrate, disc flat, sides moderately sloped; basal groove slightly recurved to rounded humeral angle, the humeri moderately narrowed relative to greatest width behind midlength, MEW/HuW = 1.93-2.05; parascutellar seta present; parascutellar striole fine, continuous, with 6 small punctures; sutural interval moderately convex, slightly more elevated than intervals 2-4; sutural and 2nd striae of subequal depth from base to apex; discal striae deep, impunctate, continuous to apex with exception of strial fusions; strial fusions include those of striae 3 and 4 in association with dorsal elytral setae, striae 5 and 6 posterad humerus, and irregularly striae 3 and 4, 4 and 5, and 5 and 6 near apex (Fig. 50A); 7th and 8th interval of similar convexity mesad subapical sinuation; 2 dorsal elytral setae at 0.29 × and 0.61 –0.65× elytral length, setal impressions foveate, spanning interval 3; apical and subapical setae present; lateral elytral setae arranged in anterior series of 7 setae and posterior series of 5 setae; elytral marginal depression narrow, lateral margin upturned; subapical sinuation very shallow, nearly obsolete. Mesepisternum with 8 shallow punctures in 2 rows; metepisternal width to length ratio = 0.86; metepisternum/metepimeron suture distinct; metathoracic flight wing an ovoid flap 2.5 × long as wide, remnant R plus M veins present, vestige extends ¾ distance to posterior margin of metanotum. Abdomen with indistinct lateral wrinkles on ventrites 1-3; suture between ventrites 2 and 3 complete; apical male ventrite with 2 marginal setae, apical female ventrite with 4 equally spaced marginal setae and median trapezoid of 4 subequal, short setae. Legs-metatarsomere 1/metatibial length ratio = 0.17; metatarsomere 4 length along outer lobe 1.3 × medial tarsomere length, apical and subapical setae present; metatarsal dorsolateral sulci broad, shallow. Microsculpture of vertex granulate iso diametric; pronotal disc with granulate transverse mesh, median base with granulate isodiametric mesh; elytral disc with elongate transverse mesh, apex with well-developed isodiametric mesh in transverse rows; metasternum with upraised transverse mesh; laterobasal abdominal ventrites with swirling isodiametric and transverse microsculpture. Coloration of vertex rufobrunneous; antennomere 1 flavous, antennomeres 2-3 rufopiceous, 4-11 piceous; pronotal disc rufobrunneous with piceous cast, margins concolorous; proepipleuron rufoflavous, proepisternum rufobrunneous with piceous cast; elytral disc rufopiceous, sutural interval paler, rufous throughout length, lateral marginal depression paler at base, 8th stria and depression paler at apex; elytral epipleuron rufoflavous, metepisternum rufobrunneous; abdomen rufopiceous across width of ventrites 1-5, apical ventrite 6 with apical 1.3 paler, rufobrunneous; metafemur flavous with piceous cast in basal 1/3; metatibia flavous with piceous cast.

Male genitalia (n = 1). Aedeagal median lobe short, robust, distance from parameral articulation to tip 2.2 × depth at midlength (Fig. 45K); apex narrowly extended beyond ostial opening 3 × its depth, tip tightly rounded at juncture of flattened apical face and downturned ventral margin; median lobe straight in ventral view, right and left margins convergent to blunt tip (Fig. 45L); internal sac unornamented, flagellar plate large, sclerotized plate visible in lateral view, plate length 0.58 × parameral articulation-tip distance.

Female reproductive tract (n = 1). Bursa copulatrix very broad basally, narrowed to a nipplelike apical lobe, overall length 0.51 mm, apical lobe width 0.09 mm, basal width at vagina 0.44 mm (Fig. 46D); bursal walls transparent at base, wrinkled in extension apicad juncture with common oviduct, apical lobe translucent, thinly wrinkled; gonocoxite 1 with 2 subequal apical fringe setae, 4 smaller setae on medial surface (Fig. 47D); gonocoxite 2 broadly subtriangular, apex tightly rounded, base broadly extended, 2 lateral ensiform setae with apical seta broader and longer, apical nematiform setae on medioventral surface at 0.72 × gonocoxite length.

Holotype.

Male (CUIC) dissected and labeled: HI: Maui Haleakala N.P. / Kaupo Gap el. 1495 m / N20°41'48", W156°08'22" / 17-18-V-2001 lot03 koa / / fern/moss litter J. Liebherr / 2 / HOLOTYPE / Mecyclothorax / inconscriptus / Liebherr / det. J.K. Liebherr 2015 (black-margined red label).

Paratypes.

HI: Maui: Haleakala N.P., Haleakala Crater, Paliku, pitfall, 1900 m el., 14-15-iii-2002, Takumi (BPBM, 1), Kaupo Gap, sift litter Acacia koa /fern/moss, 1495 m el., 17-18-v-2001 lot 03, Liebherr (CUIC, 5).

Etymology.

The Latin participle conscriptus is used as the stem of this epithet, with the converse inconscriptus signifying this species’ membership in the Mecyclothorax interruptus species group.

Distribution and habitat.

Mecyclothorax inconscriptus exhibits a Kaupō Gap distribution (Fig. 51) biogeographically congruent with that of Mecyclothorax cordaticollaris (Fig. 77). The two collecting records indicate occupation of mesic to dry ground-level microhabitats, with one specimen collected in a pitfall trap at Paliku, and a series of four individuals found in a sift sample of Acacia koa leaves, mosses, and dead fern fronds.