Mecyclothorax kipwilli, 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 : 226-230

Taxon classification Animalia Coleoptera Carabidae

(093) Mecyclothorax kipwilli sp. n. Figs 115 D–E, 117C, 118C, 120, 121

Diagnosis.

The four newly described species of the Mecyclothorax vitreus group complex-this species (Fig. 115 D–E), Mecyclothorax kipahulu (Fig. 122A), Mecyclothorax kaumakani (Fig. 122 B–C), and Mecyclothorax kuiki (Fig. 122 D–E)-were sorted for description principally by the configuration of the male aedeagus. Thus any external characters used here and in the key above are at best guideposts on the way to an identification, with a dissected male necessary for an authoritative determination, especially in the geographic area of extreme sympatry surrounding Kīpahulu Valley (Fig. 121). Nevertheless, based on available specimens, beetles of this species have the elytra more broadly ovoid relative to the width of the head across the eyes than observed in specimens of the other species; MEW/MHW = 2.18-2.21 (note: the span of these values for Mecyclothorax kuiki = 2.08-2.18). Pronotal shape, elytral striation, and microsculpture, usually of great help for species-level identification, are so variable infraspecifically that consulting the aedeagus is the only means to put a name on a specimen of this species with any confidence. That said, the male aedeagal median lobe is distinctive and relatively stable morphologically across this species’ range (Fig. 120), with the apex broad dorsoventrally and blunt apically. The aedeagal internal sac bears a ventral ostial microtrichial patch, and the lobe is only partially divided into an apical versus a basal lobe (Fig. 120G). Setal formula 2 1 2 0. Standardized body length 3.8-5.1 mm.

Description

(n = 5). Head capsule with frontal grooves deep apically near clypeus, sinuous laterally to mesad anterior supraorbital seta, separated from seta by low carina; dorsal impression of neck broad, shallow, visible dorsally; ocular lobe moderately protruded from gena, eyes moderately convex, ocular ratio = 1.46-1.53, ocular lobe ratio = 0.80-0.89; labral anterior margin broadly shallowly emarginate; antennae filiform, antennomeres 2-3 with sparse pelage of short setae; mentum tooth with sides slightly acute, apex tightly rounded. Pronotum slightly, variably transverse, MPW/PL = 1.07-1.20, variably constricted basally, MPW/BPW = 1.49-1.63; hind angle slightly acute, lateral margin slightly convergent to evenly concave (in the same specimen, Fig. 115E) anterad angle; median base with 9-14 isolated punctures each side; basal margin straight medially, slightly expanded posterad behind laterobasal depressions; median longitudinal impression very shallow, indistinct; front angles slightly projected, rounded; pronotal apex broader than base, APW/BPW = 1.05-1.14; lateral marginal depression moderately narrow, edge upturned; laterobasal depression narrow, smooth, laterally upraised to margin. Proepisternum with 6 minute punctures along hind marginal groove; prosternal process medially depressed with a low lateral marginal bead. Elytra convex, sides depressed; basal groove evenly and briefly curved to tightly rounded to obtusely angulate humerus at juncture of basal groove and lateral marginal depression; MEW/HuW = 2.32-2.44; parascutellar seta present; parascutellar striole with 4 isolated punctures; sutural interval slightly convex, lateral intervals 1-4 flat; sutural stria deep and distinct apically, whereas 2nd stria shallow, broad there; 8th interval laterad 7th stria as convex as fused apical portion of striae 5 + 7; 2 dorsal elytral setae at 0.25 × and 0.59 –0.66× elytral length, setal impressions spanning ½ width of interval 3; lateral elytral setae arranged in anterior series of 7 setae and a posterior series of 6 setae; elytral marginal depression narrow, lateral margin upturned; subapical sinuation shallow, broad. Mesepisternum with ~16 isolated punctures in 3 rows; metepisternal width to length ratio = 0.72; metepisternum/metepimeron suture distinct; metathoracic flight wing a narrow strap 2.1 × long as broad, remnant R and M veins present, strap not reaching hind margin of metanotum. Abdomen with irregular lateral wrinkles on ventrites 1-3; suture between ventrites 2 and 3 complete; apical male ventrite with 2 marginal setae and apical female ventrite with 4 equally spaced marginal setae plus median trapezoid of 4 short setae, the basal pair longer. Legs-metatarsomere 1/metatibial length ratio = 0.20; metatarsomere 4 length along outer lobe 1.5 × medial tarsomere length, apical and subapical setae present; metatarsal dorsolateral sulci broad, shallow. Microsculpture of vertex a transversely stretched mesh; pronotal disc with indistinct elongate transverse mesh, median base with isodiametric sculpticells near punctures, glossy surface in spaces between punctures; elytral disc with indistinct to obsolete isodiametric mesh in transverse rows-sculpticells visible only in small patches; elytral apex glossy with patches of indistinct isodiametric sculpticells; metasternum covered with swirling transverse mesh; laterobasal abdominal ventrites with swirling isodiametric sculpticells. Coloration of vertex a glossy brunneous; antennomeres 1-3 flavous, 4-11 rufobrunneous; pronotal disc brunneous, lateral depression and edge of disc rufoflavous; proepipleuron flavous, proepisternum rufobrunneous with piceous cast; elytral disc glossy rufobrunneous, sutural interval concolorous basally, rufoflavous apically, margins narrowly rufoflavous in lateral depression, apex rufoflavous; elytral epipleuron flavous, metepisternum rufobrunneous with piceous cast; abdomen piceous basally, lateral margins of ventrites 3-6 flavous; metafemur flavous; metatibia flavous with brunneous cast.

Male genitalia (n = 38). Aedeagal median lobe squat, evenly curved, dorsal margin very convex along left margin of ostial opening, distance from parameral articulation to tip 2.4 –2.8× depth at midlength (Fig. 120A, C–I); apex only briefly extended beyond ostial opening, obliquely blunt with apical face nearly flat to slightly convex, and ventral tip acutely rounded; median lobe straight overall in ventral view, apex curved slightly to left before rounded tip, convex dorsal margin visible to right of curved tip (Fig. 120B); internal sac broad and squat, a variably developed ventral ostial microtrichial patch (Fig. 120 D–E, G–I), and a variably developed basal lobe (Fig. 120D, G) present; flagellar plate very small, length 0.20 –0.30× parameral articulation-tip distance.

Female reproductive tract (n = 1). Bursa copulatrix broad, saclike with rounded apex, length 0.74 mm, breadth 0.46 mm (Fig. 117C); bursal walls translucent, thinly wrinkled; gonocoxite 1 with 5 apical fringe setae of 2 distinct sizes, 10-13 small setae across ventral surface (more may occur on dorsal surface but if so, they are impossible to discern) (Fig. 118C); gonocoxite 2 broadly falcate, apex subacuminate, base broadly extended laterally, 2 lateral narrow ensiform setae, apical nematiform setae on medioventral surface at 0.70 × gonocoxite length.

Holotype.

Male (BPBM) labeled: HAWAIIAN IS: Maui (E): / Haleakala Nat. Park: / ridge E of Kipahulu / Valley, Greensword Bog: / 1859m, 22-25.VI.1981 // W.C. Gagné, Coll. / BISHOP Museum / Acc. #1981.284 // HOLOTYPE / Mecyclothorax / kipwilli / Liebherr / det. J.K. Liebherr 2015 (black-margined red label).

Paratypes.

256 specimens (see Appendix).

Etymology.

This species is named to commemorate the efforts of the first person who sorted to species the many Haleakalā Mecyclothorax specimens collected during the initial years of this project. Prof. Kipling W. Will was the first to separate specimens of this species now called Mecyclothorax kipwilli .

Distribution and habitat.

Mecyclothorax kipwilli has a bipartite Waikamoi plus Hanawī/Hāna Bogs distribution, but the eastern populations are restricted in occurrence by the speciation events that spawned the other closely related species in this complex; Mecyclothorax kaumakani , Mecyclothorax kipahulu , and Mecyclothorax kuiki (Fig. 121). Records of this species have been associated predominantly with ‘ōhi‘a, and secondarily with koa . Koa records lie in the upper elevations of the range (1800-1860 m el.), whereas ‘ōhi‘a records broadly range 1310-1860 m elevation. Other plant substrates include Cheirodendron ('ōlapa), Cibotium ( hāpu‘u), Clermontia ( ‘ōhā wai), Cyanea (haha), Dubautia reticulata (kupaoa), Leptecophylla (pūkiawe), Melicope (alani), and Myrsine (kolea).