Mecyclothorax patulus, 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 : 116-117

Taxon classification Animalia Coleoptera Carabidae

(044) Mecyclothorax patulus sp. n. Figs 60B, 64

Diagnosis.

This second of the three bicolored species (Fig. 60B) exhibits more narrowly flavous elytral margins-only intervals 8-9-versus piceous discal intervals 2-7. The sutural interval is rufous basally, flavous apically. The bisetose pronotum is more transverse than that of Mecyclothorax subtilis ; MPW/PL = 1.28, and less constricted basally, MPW/BPW = 1.53. As in the next species below, Mecyclothorax patagiatus , the parascutellar and subapical elytral setae are present, but the elytral humeri are narrower in this species-MEW/HuW = 2.06 versus 2.0-and the elytra more ellipsoid. The setal impressions of the dorsal elytral setae are larger in beetles of this species, as they span interval 3. Setal formula 2 1 2 1[sae]. Standardized body length 3.4 mm.

Description

(n = 1). Head capsule with frontal grooves broad near clypeus, a lateral carina extended to mesad anterior supraorbital seta; dorsal surface of neck flat; eyes moderately convex, ocular ratio = 1.47, not extended onto posterior portion of ocular lobe, ocular lobe ratio = 0.75; labral anterior margin broadly emarginate to 1/6 of length; antennae filiform, sparse setae on apex of antennomere 1 and shafts of antennomeres 2-3; mentum tooth with sides acute, apex tightly rounded. Pronotum transverse, MPW/PL = 1.28, bisetose, glabrous hind angles obtuse, rounded behind, lateral margin subparallel for short distance anterad angle; base moderately broad, MPW/BPW = 1.53; median base nearly coplanar with disc, ~10 sparsely distributed, isolated punctures each side; basal margin convexly expanded between laterobasal depressions; median longitudinal impression shallow, finely incised, crossed by fine longitudinal wrinkles; anterior transverse impression deep, finely incised, minute irregularities in deepest part; anterior callosity convex, glossy surface with minute longitudinal wrinkles; front angles slightly projected, tightly rounded; pronotal apical width greater than basal width, APW/BPW = 1.10; lateral marginal depression narrow, edge upturned, slightly broader at front angle; laterobasal depression with slightly irregular surface, continuous with lateral depression. Proepisternum with 5 minute punctures along hind marginal groove; prosternal process with narrow median impression, lateral margins broadly beaded between coxae. Elytra broadly subellipsoid, disc flat, sides moderately sloped; basal groove evenly and distinctly recurved to tightly rounded humeral angle, MEW/HuW = 2.06; parascutellar seta present; parascutellar striole with 3-4 punctures, very shallow between punctures; sutural interval more convex than lateral intervals, sutural juncture upraised; sutural and 2nd striae of subequal depth from base to disc, 2nd stria slightly shallower at apex; discal striae 1-5 moderately broad, evident, stria 6 shallower and stria 7 shallower still, interrupted along length; striae 1-4 with minute elongate punctures, stria 5 with shallower punctures and stria 6 with only irregularities along length; intervals 2-5 moderately convex, lateral intervals less so; 8th interval slightly more convex than fused apical portion of striae 5 + 7; 2 dorsal elytral setae at 0.28 –0.32× and 0.62 × elytral length, setal impressions evident, spanning interval 3; apical elytral seta absent, subapical elytral seta present; lateral elytral setae arranged as anterior series of 6 setae and posterior series of 5 setae; elytral marginal depression narrow, edge little upturned in basal half, margin 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 on ventrites 1-5, lateral depressions on ventrites 3-6; suture between ventrites 2 and 3 complete; apical female abdominal ventrite with 4 equally spaced setae plus trapezoid of 4 subequal, short setae. Legs-metatarsomere 1/metatibial length ratio = 0.20; 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 shallow isodiametric sculpticells in rows; pronotal disc with shallow transverse mesh, sculpticell breadth 3 × length, to transverse lines not connected into mesh; pronotal median base glossy, obsolete transverse mesh between punctures; elytral disc and apex with shallow transverse mesh, sculpticell breadth 2 –4× length; 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, lateral margins, apex, and base rufoflavous; proepipleuron flavous, proepisternum rufobrunneous with piceous cast; elytral epipleuron dorsally flavous, ventrally rufoflavous, metepisternum rufobrunneous with piceous cast; abdomen with ventrites 1-2 medially, and 3-5 mediobasally rufopiceous, ventrites 3-6 apical and marginally rufoflavous; metafemur flavous; metatibia flavous with brunneous cast.

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

Holotype.

Female (NMNH) labeled: HI:Maui Koolau / F.R. Kula Pipeline Rd. / N20°48.58', W156°14.30', / 18-V-2003 lot09 el. 1305m / pyr. fog log D.A. Polhemus // HOLOTYPE / Mecyclothorax / patulus / Liebherr / det. J.K. Liebherr 2015 (black-margined red label).

Etymology.

The Latin adjective patulus means open, spread out, or broad ( Brown 1956), signifying the short, broad body of these beetles.

Distribution and habitat.

Mecyclothorax patulus is known only from an ‘Ōhi‘a Wet Forest site uphill from the junction of the Kula Pipeline and Waikamoi Flume Roads (Fig. 64). The type specimen was found in a pyrethrin fog sample of a downed ‘ōhi‘a log covered with moss.