Mecyclothorax mapo, Liebherr, James K., 2012

Liebherr, James K., 2012, The first precinctive Carabidae from Moorea, Society Islands: new Mecyclothorax spp. (Coleoptera) from the summit of Mont Tohiea, ZooKeys 224, pp. 37-80 : 56-58

Mecyclothorax mapo sp. n.

Diagnosis.

This species shares transverse-line elytral microsculpture and deep punctate elytral striae with Mecyclothorax castaneus , and individuals are of similar body size; standardized body length for this species 3.8-4.4 mm versus 3.8 mm for Mecyclothorax castaneus . The pronotum is of similar dimensions in the two species, with MPW/PL = 1.14-1.17 (n = 5) in this species, versus a ratio of 1.19 in Mecyclothorax castaneus (Perrault, 1986). The species differ in setation, with this species consistently characterized by two discal elytral setae, and therefore a setal formula of 2221, versus Mecyclothorax castaneus where one of the two type specimens had two discal setae on one elytron, whereas the other three elytra of the two beetles were unisetose. In addition, the pronotal base of this species is relatively broader, MPW/BPW = 1.52-1.64 (n = 5), versus a narrower base and greater ratio of 1.70 for Mecyclothorax castaneus .

Description.

Head capsule withfrontal grooves nearly straight on lateral margins, depressed area of frons triangular with broadest portion at frontoclypeal suture, groove terminated posteriorly at thin carina mesad anterior supraorbital seta; dorsum of head flat on frons in lateral view, neck convex; ocular lobe broadly convex, little protruded from head capsule, hind portion meeting gena at 135˚ angle, at a fine groove bordered posterad by fine carina; compound eye with 15-16 ommatidia along a horizontal diameter defined by lower margin of antennal articulatory socket; ocular ratio 1.40-1.49 (n = 5), ocular lobe ratio 0.73-0.83 (n = 5); labral anterior margin nearly straight, only slightly emarginate; antennomeres 1-3 glabrous except for apical setae; antennae submoniliform, antennomere 8 length 1.6 × greatest breadth; mentum tooth sides defining an acute angle, apex subacuminate. Pronotum quadrisetose, cordate (Fig. 3C), margin variously, slightly convergent, subparallel, or slightly divergent anterad obtuse hind angles; median base depressed relative to disc, margined anteriorly by a row of punctures, some elongate, 13-14 punctures each side of base, punctures sparser medially; basal margin convex between the laterobasal depressions; median longitudinal impression fine, shallow but continuous on disc, continued as fine impression onto front of median base; anterior transverse impression broad, shallow, smooth, finely incised only mesad front angle; anterior callosity only slightly convex, with very fine and shallow longitudinal wrinkles, variously restricted to front margin of pronotum to crossing callosity and anterior transverse impression; front angles slightly protruded, tightly rounded, apical and basal pronotal widths subequal, APW/BPW = 1.0-1.09 (n = 5); lateral marginal depression very narrow, edge beaded throughout most of length, except at front angle where margin is slightly upturned to flat, and along basolateral sinuation where margin is broadly upturned; laterobasal depression defined by linear mesal extension of lateral depression and lateral raised basolateral margin, punctures of median base not reaching deepest linear portion; proepisternum with 6 distinct punctulae along hind margin, ~5 smaller punctures along marginal collar of proepimeron; prosternal process narrowly depressed between broadly upraised lateral areas between procoxae, convex posterad at juncture with posterior face. Elytra subovoid, sides broadly convex; disc convex with sides sloping to near vertical juncture with lateral marginal depression; basal groove short, distinctly, anteriorly curved to proximate, angulate humeri, MEW/HuW = 2.29-2.43 (n = 5); parascutellar seta present; parascutellar striole 3-4 punctate, irregularly depressed or not between punctures; sutural interval dorsally expanded to meet at a sutural callous that extends to apex; striae 1-4 distinctly impressed on disc, elongately punctate at depth, striae 5-6 shallower but also elongately punctate, stria 7 reduced to series of isolated punctures; sutural stria 1 deep and smooth apically, stria 7 nearly as deep apicad subapical sinuation, 2-6 shallow, continuous, with rudimentary punctures in deeper portions; intervals 2-6 slightly convex on disc; interval 8 bulbously carinate laterad stria 7 dorsad subapical sinuation, the interval nearly vertical in orientation laterad its midpoint; two dorsal elytral setae in impressions that span ½ to ⅔ of interval 3, positioned at 0.32 –0.34× and 0.66 –0.68× elytral length; apical elytral seta present, subapical seta absent; lateral elytral setae 6 + 5; elytral marginal depre ssion narrow, edge thick and upturned at humerus, more thinly upturned laterally, beadlike anterad subapical sinuation; subapical sinuation shallowly excavate, broad. Mesepisternum anteriorly with 6 large, isolated punctures in 1-2 rows; metepisternum longer than wide, width to length ratio 0.72; metepisternum separated from metepimeron by distinct suture; metathoracic wing vestigium an elongate strap, 1.57 × long as wide that extends from base to 0.73 × length of metanotum, rudiments of R and M veins visible on strap. Abdomen with irregular wrinkles laterally on visible ventrites 1-4, rounded depressions laterally on ventrites 3-6; suture between visible ventrites 2 and 3 laterally effaced. Metatarsomere 4 triangular in dorsal view, lobate, length including lobes 1.6 × median tarsomere length, subapical and apical setae present; metarsal dorsolateral sulci shallow, lateral, tarsomeres broadly convex medially. Microsculpture of frons reduced, surface glossy, shallow transverse mesh visible adjacent to area of reflected light; pronotal disc glossy, shallow, indistinct transverse mesh, sculpticells 3 –4× broad as long, visible adjacent to area of reflected light; pronotal median base glossy between punctures; elytral disc with distinct, subiridescent transverse mesh, sculpticells 3 –4× broad as long, mixed with less cross–connected transverse lines; elytral apex with transverse mesh, sculpticells 2 –3× broad as long; metasternum glossy with obsolete transverse mesh; laterobasal abdominal ventrites glossy, covered with shallow swirling isodiametric and transverse mesh. Coloration of head capsule rufobrunneous with piceous cast; antennomeres 1-2 flavous, 3-4 rufoflavous, 5-11 slightly darker; pronotal disc rufobrunneous, anterior transverse impression rufopiceous; proepipleuron rufoflavous, proepisternum rufobrunneous; elytral disc rufobrunneous with silvery to bluish reflection; sutural interval rufous basally, rufoflavous apically; elytral lateral marginal depression concolorous with disc at humerus, increasingly paler to rufoflavous anterad subapical sinuation; elytral apex narrowly rufoflavous anterad incised portion of stria 7; elytral epipleuron rufoflavous, metepisternum rufobrunneous; abdomen rufobrunneous, lateral margins concolorous to darker, with piceous cast, abdominal apical ventrite rufoflavous in apical ¼; metafemur flavous with medial brunneous cast; metatibia flavous.

Male genitalia. (n = 3). Aedeagal median lobe broad in basal ⅔ of length, narrowed apically to broadly rounded apex with blunt apical face, ventral portion of median lobe straight (Fig. 4F); internal sac ventrally covered with dense microspiculate field, distinct ventral or dorsal microtrichial patches absent; flagellar plate large, length 0.57 × distance between parameral articulation and apex, gonopore visible on middle of dorsal surface, longitudinally radiate sclerotic ridges on inner, ventral, surface of plate; right paramere narrowly elongate (Fig. 4G), tip extended 0.85 × distance from parameral articulation to apex, left paramere slightly longer, extended 0.90 × such distance.

Female reproductive tract. (n = 1). Bursa copulatrix constricted basally apicad juncture with common oviduct (Fig. 5D), bursa columnar, length 3 × greatest breadth in slide–mounted dissection, surface thin, membranous based on staining with Chlorazol Black; spermatheca reniform, spermathecal duct heavily sclerotized, inflexible; spermathecal gland attached to spermatheca by an elongate duct; basal gonocoxite 1 with 2-3 apical fringe setae, and 2-3 smaller setae along the mesal surfaces of coxite (Fig. 6D); gonocoxite 2 broad basally, subacuminate apically, the lateral margin broadly concave; 2 lateral ensiform setae, 1 dorsal ensiform seta, and 2 apical nematiform setae present on gonocoxite 2.

Holotype male (MNHN), labeled: French Polynesia: Moorea / Tohiea summit el. 1125- / 1200 m 12 –IX– 2006 lot 01 / 17°33.03'S, 149°49.33'W / beating ferns & Myrsine / J.K. Liebherr // HOLOTYPE / Mecyclothorax / mapo / J.K. Liebherr 2012 ( black–bordered red label).

Allotype female (MNHN), labeled as holotype but with black–bordered red ALLOTYPE label.

Other Paratypes.

SOCIETY ISLANDS. Moorea: Tohiea summit, 1125-1200 m el., S17°33.03', W149°49.33', 12 –ix– 2006 lot 01, beating Myrsine + ferns, Liebherr (CUIC, 8); 1125 m el., S17°33.07', W149°49.38', 12 –ix– 2006 lot 02, pyrethrin fog Weinmannia moss + roots, Liebherr (CUIC, 3); 1120 m el., S17°33.07', W149°49.38', 12 –ix– 2006 lot 03, beating Dicranopteris ferns, Liebherr (CUIC, 5); lot 05, beating rotten Freycinetia , Liebherr (CUIC, 4); 1150-1200 m el., S17°33.03', W149°49.33', 12 –ix– 2006 lot 07, beating flowering Myrsine at night, Liebherr (CUIC, 12; NMNH, 2); 1120 m el., S17°33.07', W149°49.38', 12 –ix– 2006 lot 08, beating ferns, Ewing (EMEC, 2); 1120 m el., S17°33.07', W149°49.38', 12 –ix– 2006 lot 09, dead fern fronds, deep gulch, Ewing (CUIC, 2; EMEC, 2); 1120 m el., S17°33.07', W149°49.38', 12 –ix– 2006 lot 10, pyrethrin fog mossy log, deep gulch, Polhemus (NMNH, 4); gulch S of summit 1160-1180 m el., S17°33.03', W149°49.36', 24 –ix– 2009 on fern frond, gulch wall, MBIO 5852, Ewing & Yang (EMEC, 5); muddy gulch on trail, 1150 m el., S17°33.08', W149°49.31', 24 –ix– 2009, pyrethrin fog mossy tree trunk, MBIO 5856, Ewing (CUIC, 1; EMEC, 1); summit along ridge to west, 1190-1207 m el., S17°33.04', W149°49.34', 24 –ix– 2009, beating Myrsine , MBIO 5857, Ewing (CUIC, 1; EMEC, 6); muddy gulch on trail, 1150 m el., S17°33.08', W149°49.31', 24 –ix– 2009, beating Angiopteris evecta , MBIO 5854, Stavrinides (EMEC, 2); 1170 m el., S17°33.08', W149°49.31', 25 –ix– 2009, pyrethrin fog mossy tree, MBIO 5853, Ewing (EMEC, 2); 1150 m el., S17°33.08', W149°49.31', 25 –ix– 2009, pyrethrin fog mossy tree trunk, MBIO 5859, Ewing (EMEC, 1); gulch S of summit, 1150-1170 m el., S17°33.03', W149°49.36', 26 –ix– 2009, on fern frond steep gulch, MBIO 5861, Ewing (EMEC, 3).

Etymology.

Given that this species is most similar to Mecyclothorax castaneus , the common name of the Tahitian chestnut tree, Inocarpus fagifer (Parkinson) ( Fabaceae )-i.e. mapo (Wahlroos, 2002)-was chosen for the species epithet. The epithet is to be treated as a noun in apposition.

Distribution and habitat.

This species has been found in a variety of situations on Mont Tohiea, accounting for 68 of the 90 specimens of Mecyclothorax collected on or near the summit. Specimens have been found by sampling ferns, Angiopteris , rotten Freycinetia , Myrsine foliage and flowers, and moss–covered Wienmannia trunks and roots. In keeping with this species’ numerical dominance, it has been collected in association with all other Mecyclothorax spp. known from Mont Tohiea.