Mecyclothorax perseveratus, 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 : 20-21

Taxon classification Animalia Coleoptera Carabidae

(001) Mecyclothorax perseveratus sp. n. Figs 10A, 11 A–C, 12A, 13A, 14

Diagnosis.

This is the largest bodied of the three Haleakalā species in this group (Fig. 10A); standardized body length 4.5-4.8 mm versus 3.5-4.6 mm for the other two species below. Dorsal microsculpture is more developed in this species, with the elytral disc covered with an elongate transverse mesh and parallel lines, and the pronotal disc bearing an evident transverse mesh. Setal formula 2 1 1(2) 0.

Description

(n = 3). Head capsule with frontal grooves straight, bordered by a lateral carina and mesal wrinkles; neck flat to slightly concave; eyes convex, largely covering ocular lobe, ocular ratio 1.52-1.55, ocular lobe ratio 0.89-0.94; labral anterior margin very shallowly emarginate; antennae filiform, antennomeres 2-3 covered with sparse pelage of small setae; mentum tooth narrow with acute sides, apex tightly rounded. Pronotum with lateral seta present, basal seta absent; MPW/BPW = 1.52-1.66; MPW/PL = 1.11-1.23; hind angle right to slightly acute; lateral margin convergent to subparallel anterad hind angle; median base with small punctures, sparse medially, denser laterally; basal margin broadly, slightly convex between laterobasal depressions; median longitudinal impression finely incised, shallow; anterior transverse impression distinct, slightly punctate in middle half; anterior callosity slightly convex, traversed by shallow wrinkles; front angles slightly protruded, tightly rounded; APW/BPW = 1.0-1.04; lateral marginal depression moderately narrow, flat near front angle, edge upturned; laterobasal depression a continuation of lateral depression, surface irregularly punctate. Proepisternum with 6 small punctures along hind marginal groove; prosternal process with narrow median impression, lateral margins a narrow bead anterad. Elytra broadly ovoid, convex, suture elevated relative to disc; basal groove nearly straight laterad scutellum, humeral angle subangulate, defined by a hitch at base of lateral depression; humeri broadly rounded, MEW/HuW = 2.11-2.14; elytra broad relative to pronotum and head, MEW/MPW = 1.50-1.59, MEW/MHW = 2.18-2.29; parascutellar seta present; parascutellar striole with 2-4 punctures, striole shallow between punctures; juncture of sutural intervals each side upraised, producing a median callus; depth of sutural or first stria subequal to 2nd stria from base to apex; discal stria finely punctate basally, narrow and smooth apically; lateral striae punctate basally, the punctures small, slightly expanding striae in basal half, punctures absent apically; intervals 2-7 moderately convex; all striae finely incised apically; 8th interval laterad 7th stria not more convex apically than other intervals; either 1 or 2 dorsal elytral setae, if two, then setae at 0.10 × and 0.28 –0.33× elytral length, if one seta, then situated 0.24 –0.30× elytral length; apical and subapical setae absent; lateral elytral setae arranged as 7 + 6 (anterior and posterior series); elytral marginal depression narrow, lateral margin upturned; subapical sinuation broadly excavated, shallow, internal plica visible from dorsal view. Mesepisternum punctate, ~13 punctures in 2-3 vertical rows; metepisternal medial length/maximum width = 1.39; metepisternum/metepimeron suture distinct. Abdomen with irregular longitudinal wrinkles on ventrites 1-4, suture between ventrites 2 and 3 complete; males with 2 apical abdominal setae, females with 4 equally spaced setae plus 4 short setae arranged in a median trapezoid. Legs-metatarsomere 1/metatibial length ratio = 0.195; metatarsomere 4 lobe length 1.5 × medial tarsomere length, subapical and apical setae present; metatarsal dorsolateral sulci very narrow, shallow, evident on mt1 and mt2 only. Microsculpture of head capsule transverse, vertex with transverse mesh and fine wrinkles; pronotal disc with evident, reflective transverse-mesh microsculpture; pronotal median base with reflective isodiametric mesh in transverse rows; elytral disc with elongate transverse mesh and parallel lines, apex with evident transverse mesh; metasternum covered with transverse mesh; laterobasal abdominal ventrites with swirling isodiametric and transverse sculpticells. Coloration of vertex brunneous with a slight piceous cast; antennomeres 1-3 flavous, 4-11 rufobrunneous; pronotal disc rufobrunneous, pronotal margins slightly, broadly paler; proepipleuron rufoflavous, proepisternum brunneous with piceous cast; elytral disc rufobrunneous, darkest behind middle, sutural interval paler, rufous basally, flavous apically; elytral margins concolorous with disc basally, broadly paler apically; elytral apex broadly flavous, flavous coloration extended anterad along suture; elytral epipleuron rufoflavous, metepisternum brunneous; abdominal ventrites 1-3 brunneous medially, more apical ventrites flavous; metafemur flavous, metatibia flavous with brunneous cast.

Male genitalia (n = 1). Aedeagal median lobe gracile, elongate, distance from parameral articulation to tip 4.7 × depth at midlength (Fig. 11A); median lobe apex parallel sided with rounded tip, apex evenly downcurved distad ostial opening in lateral view (Fig. 11 A–B), apex curved to right with top expanded as a knob in ventral view (Fig. 11C); internal sac elongate, flagellar plate small, sac covered with fine spicules only.

Female reproductive tract (n = 1). Bursa copulatrix columnar, base broad at vagina, narrower at midlength, bursal length 0.80 mm, breadth 0.40 mm at base (Fig. 12A); bursal surface translucent, wrinkled, not sclerotized; gonocoxite 1 with 2-3 apical fringe setae, 1 small seta at apicomedial angle, 4-5 setae along medial surface (Fig. 13A); gonocoxite 2 subacuminate with lateral panhandle extension; 2 moderately elongate lateral ensiform setae, 0.36 × length of gonocoxite; apical nematiform setae on medial surface at 0.80 × gonocoxite length.

Holotype.

Male (CUIC) labeled: HI: Maui Haleakala Kula / Pipeline Rd. W Waikamoi / Gulch 15-V-1998 lot04 / 1160 m el. pyr. fog mossy / ohia/ logs J.K. Liebherr // HOLOTYPE / Mecyclothorax / perseveratus / Liebherr / det. J.K. Liebherr 2015 (black-margined red label).

Paratypes.

HI: Maui: Koolau For. Res., Kula Pipeline Rd., pyrethrin fog Metrosideros /moss, 1160 m el., 15-v-1998 lot 06, Polhemus (NMNH, 1), wet forest, yellow pan trap, 1183-1280 m el., vi-viii-2006, Leblanc (CUIC, 1; UHIM, 1), Makawao Flume Rd., ecotone forest, yellow pan trap, 1293 m el., vi-viii-2006, Leblanc (CUIC, 1; UHIM, 2), Waikamoi flume tanks [labeled Waikamoi N.C.P.], 1275 m el., 30-v-1993, Tauber/Tauber (CUIC, 1).

Etymology.

The adjectival species epithet perseveratus is based on the verb perseverate; to repeat insistently or redundantly. Such a name could be appropriately applied for any number of Hawaiian Mecyclothorax , but it is used here as the name shares the first syllable with the following cryptic sibling species.

Distribution and habitat.

Mecyclothorax perseveratus is known to occur only in the Waikamoi drainage from 1160-1300 m elevation (Fig. 14). As such, the species is sympatric with lower elevational populations of Mecyclothorax perstriatus . Individuals have been collected from the trunks of moss-covered ‘ōhi‘a trees, as well as from mossy downed logs of the same species. The beetles must actively walk across the forest floor, as they have been collected from fluid-filled yellow-pan traps.