Mecyclothorax patagiatus, 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 : 117-120

Taxon classification Animalia Coleoptera Carabidae

(045) Mecyclothorax patagiatus sp. n. Figs 60C, 61 A–B, 64

Diagnosis.

This, the third Haleakalā Mecyclothorax ovipennis group species to display bicolored elytra (Fig. 60C), can be diagnosed by the following combination: 1, discal elytral striae 1-6 rufobrunneous with piceous cast, intervals 7-9 contrastedly rufoflavous; 2, pronotal disc also rufobrunneous with piceous cast, pronotal margins rufoflavous; 3, parascutellar seta present; 4, subapical elytral seta present, apical seta absent; 5, pronotal lateral margins slightly divergent from hind obtuse hind angles; 6, elytral humeri broadly rounded, the elytra broadly subquadrate, MEW/HuW = 2.0. Criteria 1, 5, and 6 diagnose this species from both Mecyclothorax subtilis and Mecyclothorax patulus , whereas criteria 2, 3, and 4 diagnose this species from Mecyclothorax subtilis . The pronotum of the unique holotype has the basal pronotal seta present on the right side, with the left hind angle glabrous (specimen examined at 125 ×), obviating use of this character in the diagnosis. Setal formula 2 1-2 2 1[sae]. Standardized body length 3.8 mm (slightly larger than both preceding species).

Description

(n = 1). Head capsule with frontal grooves broad near clypeus, lateral carina to anterior supraorbital seta; dorsal surface of neck flat; eyes moderately convex, ocular ratio = 1.43, ocular lobe ratio 0.78; labral anterior margin broadly emarginate to 1/6 of length; antennae filiform, antennomeres 2-3 with sparse pelage of short setae; mentum tooth with sides acute, apex tightly rounded. Pronotum transverse, MPW/PL = 1.30, base moderately constricted, MPW/BPW = 1.50; hind angle obtuse, margin behind rounded; median base moderately depressed, ~20 punctures or strigose wrinkles each side; basal margin convexly expanded between laterobasal depressions; median longitudinal impression evident, finely incised, joined by fine transverse wrinkles; anterior transverse impression deep, finely incised, minute irregularities in deepest part; anterior callosity elevated, flat, crossed by indistinct longitudinal wrinkles; front angles projected, broadly rounded; apical and basal pronotal widths subequal, APW/BPW = 1.03; lateral marginal depression moderate, edge upturned, broader at front angle; laterobasal depression narrowly concave, continuous with lateral depression. Proepisternum with 5 minute punctures along hind marginal groove; prosternal process narrowly impressed medially, lateral margins broadly beaded between coxae. Elytra with disc flat, sides moderately sloped; basal groove slightly recurved to broadly rounded humerus; parascutellar striole with 3-4 punctures, shallow between punctures; sutural interval coplanar with lateral intervals basally, upraised in apical half; sutural and 2nd striae of subequal depth and breadth from base to apex; discal striae 1-5 broad, deep, stria 6 shallower and more irregular, stria 7 shallower still; sutural stria deep, finely punctate basally, deep, narrow, and smooth apically; striae 2-4 with minute punctures on disc, punctures shallower in stria 5, linear irregularities in stria 6; discal intervals 2-4 convex, lateral intervals less so; 8th interval slightly more convex than fused apical portion of striae 5 + 7; 2 dorsal elytral setae at 0.27 × and 0.54 × elytral length, setal impressions small, spanning ½ width of interval 3; lateral elytral setae arranged in anterior series of 6 setae, posterior series of 5 setae; elytral marginal depression narrow, margin little upturned in basal half, beadlike near subapical sinuation; subapical sinuation very shallow, nearly obsolete. Mesepisternum with ~6 punctures in 1-2 rows; metepisternal width to length ratio = 0.80; metepisternum/metepimeron suture distinct. Abdomen with irregular lateral wrinkles in ventrites 1-5, lateral depressions in ventrites 3-6; suture between ventrites 2 and 3 complete; apical male ventrite with 2 marginal setae. Legs-metatarsomere 1/metatibial length ratio = 0.19; metatarsomere 4 length along outer lobe 1.3 × medial tarsomere length, apical and subapical setae present; metatarsal dorsolateral sulci narrow, shallow, median surface broad. Microsculpture of vertex with evident isodiametric sculpticells in transverse rows; pronotal disc with shallow transverse mesh, sculpticell breadth 3 × length, to transverse lines; pronotal median base with shallow transverse mesh laterally, median area glossy; elytral disc with evident transverse mesh, sculpticell breadth 2 –4× length, apex with more distinct transverse mesh of same dimensions; metasternum with 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 rufobrunneous with piceous cast, margins rufoflavous; proepipleuron rufoflavous, proepisternum rufobrunneous with piceous cast; elytral sutural interval concolorous with disc basally, rufoflavous apically; elytral epipleuron dorsally flavous, ventrally rufoflavous; metepisternum rufobrunneous; abdomen with ventrites 1-2 medially, 3-5 mediobasally rufopiceous, 3-6 apically and marginally rufoflavous, apical ventrite 6 with apical ¾ paler, flavous; metafemur flavous; metatibia flavous with brunneous cast.

Male genitalia (n = 1). Aedeagal median lobe robust, distance between parameral articulation and tip 3.2 × depth at midlength (Fig. 61A); extension of apex beyond ostial opening parallel sided at base and evenly narrowed dorsoventrally to tightly rounded tip; median lobe curved sinuously leftward toward apex in ventral view, the right margin distinctly concave, left margin convex (Fig. 61B); internal sac without ornamentation, flagellar plate elongate, length of sclerotized plate 0.54 × parameral articulation-tip distance.

Holotype.

Male (CUIC) dissected and labeled: HI: E.Maui, Kuhiwa / 2950 ft.,10June1999 / Cibotium chamissois / Dead fronds // C. Ewing Coll. / 20°46'25"N / 156°06'04"W // HOLOTYPE / Mecyclothorax / patagiatus / Liebherr / det. J.K. Liebherr 2015 (black-margined red label).

Etymology.

The Latin stem for this species epithet is patagium; i.e. a gold edging or border ( Brown 1956). The adjectival form patagiatus signifies the pale elytral border of beetles of this species.

Distribution and habitat.

Mecyclothorax patagiatus is known from 900 m elevation in the Kuhiwa Valley of the Hanawī windward face of Haleakalā (Fig. 64). The type specimen was collected from dead Cibotium ( hāpu‘u) tree fern fronds along with one specimen each of Bembidion haleakalae Liebherr, Mecyclothorax mauiae (Fig. 71), and Mecyclothorax bacrionis (Fig. 112).