Mecyclothorax medeirosi, 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 : 88-90

Taxon classification Animalia Coleoptera Carabidae

(032) Mecyclothorax medeirosi sp. n. Figs 49 C–D, 51

Diagnosis.

Like Mecyclothorax arthuri in exhibiting tortuously anastomosed elytral striae, though in this species all striae from the sutural to 7th stria are involved (Fig. 49C). This species also differs in the relatively broader pronotum; MEW/MPW = 1.47 versus a ratio of 1.64-1.67 for the former species. The pronotum itself is broader, more transverse, MPW/PL = 1.38, versus MPW/PL = 1.21-1.26 in Mecyclothorax arthuri . The elytra are also broader basally in this species, with the lateral elytral margins rounded more broadly laterad the angulate humeri (Fig. 49C) than observed in individuals of Mecyclothorax arthuri (Fig. 49 A–B); MEW/HuW = 1.98 versus values of 2.07-2.16 for the other species. Finally, elytral setation differs between the species, with Mecyclothorax medeirosi characterized by three dorsal elytral setae and presence of both apical and subapical setae, producing a setal formula of 2 1 3 2. Standardized body length 4.35 mm.

Description

(n = 1). Head capsule with frontal grooves sinuous, broad near clypeus and with lateral carina posteriorly; dorsal surface of neck slightly concave; eyes convex, ocular lobe protruded from gena, ocular ratio = 1.48, ocular lobe ratio = 0.75-0.79; labral anterior margin broadly, moderately emarginate, antennae filiform, antennomeres 2-3 with sparse pelage of short setae; mentum tooth with sides acute, apex rounded. Pronotum bisetose, hind angles glabrous; base moderately constricted, MPW/BPW = 1.51; hind angle right to obtuse with rounded apex, lateral margin subparallel to slightly divergent anterad angle; median base smooth medially, 5-6 punctures mesad laterobasal depressions; basal margin slightly convex medially; median longitudinal impression deep, broad, medially incised, crossed by transverse wrinkles; anterior transverse impression deeply incised, complete, slightly irregular; anterior callosity broadly convex, crossed by many fine wrinkles; front angles slightly projected, tightly rounded; apical and basal widths subequal, APW/BPW = 1.02; lat eral marginal depression moderate, edge upturned to beaded; laterobasal depression broad, flat to slightly upraised by low tubercle. Proepisternum with 5 minute punctures along hind marginal groove; prosternal process medially depressed, with narrow marginal bead. Elytra broadly subquadrate, disc moderately convex along entire length; basal groove distinctly recurved to subangulate humeral angle; parascutellar seta present; parascutellar striole narrow, deep, isolated from sutural stria; sutural and 2nd striae of subequal depth from base to apex; adjacent striae from the sutural stria to stria 7 confusedly fused, producing numerous, approximately symmetrical wartlike protuberances, all intervals convex, the warts incorporating portions of more than one interval; discal striae smooth, lined with sculpticells only; 7th and 8th interval of similar convexity mesad subapical sinuation; 3 dorsal elytral setae at 0.29 ×, 0.51 ×, and 0.64 × elytral length, setal impressions very small, shallow, but associated with depressed discal strial fusions; apical and subapical setae present; lateral elytral setae arranged as anterior series of 7 setae and a posterior series of 5-6 setae, with an isolated intermediate seta present on left side; elytral marginal depression broad along anterior setal series, moderate at midlength, narrower behind; subapical sinuation shallow, broad. Mesepisternum with ~9 shallow punctures in 1-2 rows; metepisternum nearly quadrate, width to length ratio = 0.93; metepisternum/metepimeron suture distinct. Abdomen with indistinct lateral wrinkles on ventrites 1-3; suture between ventrites 2 and 3 complete; apical female ventrite with 4 equally spaced marginal setae, a median trapezoid of 4 setae, the basal setae shorter, a 5th seta on right side. Legs-metatarsomere 1/metatibial length ratio = 0.15; metatarsomere 4 length along outer lobe 1.67 × me dian base, the tarsomere broad, robust, apical and subapical setae present; metatarsal dorsolateral sulci broad, shallow. Microsculpture of vertex a granulate isodiametric mesh; pronotal disc with granulate isodiametric mesh, some sculpticells in transverse rows; pronotal median base with granulate isodiametric mesh; elytral disc and apex with very shallow isodiametric sculpticells in shallow rows; metasternum with upraised transverse mesh; laterobasal abdominal ventrites with swirling isodiametric and transverse microsculpture. Coloration of vertex rufobrunneous with piceous cast; antennomere 1 flavous, antennomeres 2-11 piceous; pronotal disc rufobrunneous, margins broadly paler, rufoflavous; proepipleuron flavous, proepisternum piceous (Fig. 49D); elytral disc with rufobrunneous intervals and darker brunneous depressions and striae, sutural interval concolorous with lateral intervals; elytral margins rufoflavous, apex broadly flavous; elytral epipleuron flavous, metepisternum piceous; abdomen broadly brunneous, a piceous cast mediobasally, abdominal apical ventrite broadly flavous (Fig. 49D); metafemur flavous with indistinct median rufous cloud; metatibia rufobrunneous.

Female reproductive tract. The lone female holotype was not dissected.

Holotype.

Female (CUIC) labeled: HI: Maui Haleakala N.P. / Northeast Rift New / Greensword Bog sift ex / larger ohias / 17-V-1993 / lot 04 el. 1850 m // J.K. Liebherr & / A.C. Medeiros / Collectors // HOLOTYPE / Mecyclothorax / medeirosi / Liebherr / det. J.K. Liebherr 2015 (black-margined red label).

Etymology.

This is the second patronym to honor the contributions of Dr. Art Medeiros, most specifically for field collecting efforts validated in this revision, and more broadly for his leadership in Hawaiian conservation biology (e.g., Perkins et al. 2014). Both Mecyclothorax arthuri and Mecyclothorax medeirosi occupy distributional ranges in Kīpahulu Valley and the Hāna Bogs region of Haleakalā (Fig. 51). Based on the species known to science to date, the species’ hypothesized sister-taxon relationship can be signified by the convention, Mecyclothorax arthuri + Mecyclothorax medeirosi .

Distribution and habitat.

The single specimen used as the basis for this species description was collected by sifting humus and leaf litter from under an ‘ōhi‘a tree adjacent to New Greensword Bog (Fig. 51).