Mecyclothorax dispar, 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 : 201-203

Taxon classification Animalia Coleoptera Carabidae

(084) Mecyclothorax dispar sp. n. Figs 100E, 101

Diagnosis.

Most similar (Fig. 100E) to the preceding Mecyclothorax gracilicollis (Fig. 100D) in elytral striation but larger bodied; standardized body length 4.75 mm. Also differing in the more broadly based pronotum-MPW/BPW = 1.51-and the glossy elytra with only patches of transverse-mesh microsculpture, sculpticell breadth 2 –3× length, between the glossy portions. The unique holotype is slightly teneral–the left elytron failed to fully inflate–but the legs exhibit the smoky brunneous femoral apex that is shared with Mecyclothorax crassuloides (Fig. 100B) and Mecyclothorax crassulus (Fig. 100C). Setal formula 2 1 2 0.

Description

(n = 1). Head capsule with frontal grooves deep and broad near clypeus, sinuously curved toward eye and terminated mesad a thin, low carina at anterior supraorbital seta; dorsal impression of neck slightly concave; eyes moderately convex, ocular ratio = 1.47, large, covering much of ocular lobe, ocular lobe ratio = 0.88; labral anterior margin angularly emarginate medially to 1/8 of labral length; antennae filiform, antennomeres 2-3 with sparse pelage of short setae; mentum tooth with sides acute, apex rounded. Pronotum appearing longer than broad, but MPW/PL = 1.18; hind angle right, margin slightly rounded behind, lateral margin subparallel for 0.1 × length before angle; median base slightly depressed relative to disc, ~8 isolated punctures each side and minute longitudinal wrinkles along margin; basal margin slightly convex between laterobasal depressions; median longitudinal impression very finely incised, situated in slight depression of disc, crossed by indistinct longitudinal wrinkles; anterior transverse impression broad, moderately deep, smooth, narrowly incised at front angles; anterior callosity slightly convex, smooth, glossy; front angles slightly produced, rounded; apical and basal pronotal widths equal; lateral marginal depression very narrow, edge beadlike, slightly broader at front angle; laterobasal depression with slightly irregular surface, broadest apically and narrowed to hind angle. Proepisternum with 5 minute punctures along hind marginal groove; prosternal process narrowly medially depressed. Elytra subquadrate to slightly ovoid (left elytron slightly deformed), disc slightly depressed along suture, sides distinctly sloped to lateral marginal depression; basal groove distinctly curved to angulate humerus at juncture with lateral marginal depression, MEW/HuW = 2.17; parascutellar seta present; parascutellar striole with 4 punctures, deep, continuous; sutural interval more convex than 2nd interval throughout length, disc depressed at sutural interval; sutural stria broad, shallow, and smooth basally, deeper and more finely incised apically; discal striae 2-6 very shallow but traceable, associate intervals very slightly convex; 8th interval laterad 7th stria slightly more convex than apical fused portion of striae 5 + 7; 2 dorsal elytral setae at 0.30 × and 0.59 × elytral length, setal impressions very small, spanning ½ width of interval 3; lateral elytral setae arranged in anterior series of 7 setae and posterior series of 5-6 setae; elytral marginal depression broadest at humeral angle, margin upturned in basal half, beaded toward subapical sinuation; subapical sinuation deep, abruptly incurved anteriorly. Mesepisternum with ~9 punctures in 1-2 rows; metepisternal width to length ratio = 0.7; 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 partially effaced; apical female ventrite with 4 equally spaced setae and median trapezoid of 4 subequal, short 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 broad, shallow, median area subcarinate. Microsculpture of vertex an obsolete transverse mesh, sculpticell breadth 2 × length, surface glossy; pronotal disc with obsolete microsculpture, surface glossy, median base glossy with indistinct transverse sculpticells laterally; elytral apex with shallow transverse mesh, sculpticell breadth 2 –3× length; metasternum with shallow transverse mesh, sculpticell breadth 3 –4× length; laterobasal abdominal ventrites with swirling isodiametric and transverse microsculpture. Coloration of vertex rufous with piceous cast (based on estimate from teneral type); antennomere 1 rufoflavous, antennomeres 2-3 rufobrunneous, 4-11 with piceous cast; pronotal disc rufous to rufobrunneous, lateral margins concolorous, base and apex rufoflavous; proepipleuron rufoflavous, proepisternum rufoflavous dorsally, rufobrunneous ventrally; elytral disc rufous with brunneous cast, sutural interval rufous basally, rufoflavous apically; elytral interval 9 rufopiceous, marginal depression rufoflavous; elytral apex rufoflavous only on interval 8 and along apical margin; elytral epipleuron flavous, metepisternum rufoflavous; abdominal ventrites 1-3 rufobrunneous, 4-6 rufoflavous, apical half of apical ventrite 6 flavous; metafemur flavous with smoky brunneous base and apex; metatibia rufobrunneous with piceous cast.

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

Holotype.

Female (CUIC) labeled: HI: Maui Haleakala N.P. / Kipahulu Vy. Central / Pali Tr. 1200 m el. / 29-IV-1991 sifting / moss & leaf litter // J.K. Liebherr / A.C. Medeiros / Jr. collectors // HOLOTYPE / Mecyclothorax / dispar / Liebherr / det. J.K. Liebherr 2015 (black-margined red label).

Etymology.

The adjectival species epithet dispar means different, or unequal in Latin ( Brown 1956), and is used here to represent the unusual body proportions that characterize this species.

Distribution and habitat.

Mecyclothorax dispar is known only from the type collected at 1200 m elevation along the Central Pali Trail, Kīpahulu Valley. The specimen was collected from the first set of sift samples completed by Liebherr and Medeiros in Kīpahulu Valley (Fig. 101). We collected four sift samples of about 2 l volume each, and collected beetles from the siftate as it lay spread on a beating sheet. The siftate included litter from ‘ōhi‘a and Cibotium ( hāpu‘u), as well as moss from the drier undersides of downed logs. The litter was extremely wet from rain; e.g. 9 cm of rain fell the night after this daytime sampling (unpubl. data). Other Mecyclothorax spp. collected in these samples included: Mecyclothorax aquilus , Mecyclothorax manducus , Mecyclothorax mauiae , Mecyclothorax ovipennis , Mecyclothorax pau , Mecyclothorax poouli , and Mecyclothorax simpulum .