Mecyclothorax perraulti, 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 : 44-46

Mecyclothorax perraulti sp. n.

Diagnosis.

Consistent with species group membership, the pronotal lateral margins are broadly explanate and translucent, with the basolateral margin sinuate anterad the projected, nearly right hind angles (Fig. 2A). The elytral lateral margin is also broadly expanded and translucent, with the margin upraised just laterad the angulate humerus. Mecyclothorax perraulti is most similar to Mecyclothorax gourvesi , though the pronotal base is narrower relative to pronotal maximum width in Mecyclothorax perraulti (MPW/BPW = 1.49-1.52), versus the basally broader pronotum of Mecyclothorax gourvesi (MPW/BPW = 1.37-1.39). The male aedeagal median lobe of Mecyclothorax perraulti has a broadened, adze-shaped apex, with the apical face straighter than the dorsal and ventral margins (Fig. 4A). Individuals of Mecyclothorax perraulti are also larger than those of Mecyclothorax grouvesi ; standardized body length 5.8-6.2 mm versus a body length of 5.5 mm for the latter ( Perrault 1988). Setal formula: 2122.

Description.

Head capsule with broadly excavate, straight frontal grooves, bordered laterally by a finely raised carina just mesad the anterior supraorbital seta, the mesal face indistinctly wrinkled between the eyes; neck not depressed dorsally between the eyes, frons flat in lateral view; ocular lobe distinctly projected, the posterior margin abruptly meeting gena behind eye, a fine, shallow groove at ocular lobe-genal juncture; ocular ratio 1.48-1.58 (n = 4); ocular lobe ratio 0.79-0.85 (n = 4); anterior margin of labrum broadly, shallowly emarginate, emargination about ¹�₉ labral length; antennomeres 1-3 glabrous except for apical setae; antennae filiform, antennomere 8 length 2.4 × greatest width; mentum tooth with sides defining an acute angle, the apex tightly rounded. Prothorax moderately transverse, MPW/PL = 1.24-1.31 (n = 4); median base slightly depressed relative to disc, 25-27 small, isolated punctures each side of depressed area; basal margin broadly convex between laterobasal depressions, nearly straight medially; median longitudinal impression fine and shallow on disc, a lenticular broadening at front of median base; anterior transverse impression finely incised throughout breadth, shallower medially; anterior callosity slightly convex, crossed with indistinct longitudinal wrinkles; front angles protruded, subangulate medially adjacent to head, broadly convex laterally; distance between front angles less than between hind angles, APW/BPW 0.87-0.94 (n = 4); lateral marginal depression canaliculate where the convex pronotal disc meets the explanate, angularly upraised lateral margin; laterobasal depression a linear extension of the narrow, deep lateral depression; proepisternum with ~7 indistinct punctulae along hind margin, smaller irregularities along posterior ma rginal bead of proepimeron; prosternal process broad, slightly depressed anterad coxal cavities, convex posteriorly at juncture with posterior face. Elytra subquadrate, MEW/HuW = 2.29-2.37 (n = 4); disc flat medially, markedly sloped laterad interval 7 to near vertical juncture with lateral marginal depression; basal groove indistinctly though broadly recurved to angulate humerus; parascutellar seta present; parascutellar striole 6-7 punctate, continuously depressed between punctures; sutural interval elevated to sutural juncture, more convex than intervals 2-4; sutural and second striae subequally depressed at elytral apex; striae 1-7 minutely punctate basally, smooth apically, intervals distinctly convex; eighth interval distinctly carinate laterad stria 7 in apical half of elytron, the lateral portions of interval 8 depressed enhancing carina and change in discal curvature; 2 dorsal elytral setae, positioned at 0.24 –0.25× and 0.57 –0.61× elytral length, each seta in an indistinct depression that spans half or less the width of interval 3; both apical and subapical setae present; lateral elytral setae 7 + 6; elytral marginal depression broadly reflexed, translucent posterolaterad humerus; slightly broader laterad anterior lateral elytral setal series, narrowed apically to a beadlike margin anterad subapical sinuation; subapical sinuation abrupt, internal plica evident beneath sinuation in ectal view. Mesepisternum distinctly punctate anteriorly, ~18 evident punctures in 2-3 rows; metepisternum moderately foreshortened, width to length ratio 0.67; mesepisternal/mesepimeral suture distinct; metathoracic flight wing a narrow, elongate vestigium, length 3 × width, remnants of veins C, R, M, and Cu discernible. Abdomen with visible ventrites 1-4 irregularly wrinkled laterally, ventrites 3-6 with round depressions laterally; suture between visible ventrites 2 and 3 effaced laterally. Legs moderately elongate, ratio of metatarsomere 1 length to metatibia length 0.23; metatarsomere 4 lobate, length including outer apical lobe 1.5 × median tarsomere length; metatarsomere 4 with apical setae only, subapical setae absent; metatarsal dorsolateral sulci very shallow, obsolete, tarsomere dorsum broadly convex. Microsculpture of frons obsolete, surface glossy, shallow isodiametric sculpticells in transverse rows on neck; pronotal disc with mesh of transverse sculpticells 2 –3× broad as long; pronotal median base covered with irregular, swirling isodiametric and transverse sculpticells between punctures; elytral disc with transverse microsculpture, sculpticells connected into a mesh, to parallel, unconnected transverse lines; metasternum covered with distinct transverse mesh; basal 2 abdominal ventrites covered with swirling isodiametric and transverse sculpticells. Coloration a somber reddish brown; head capsule rufous with a piceous cast; antennomere 1 rufoflavous, 2-11 rufobrunneous; pronotal disc rufopiceous, base, apex and lateral margins rufobrunneous; proepipleuron rufoflavous, proepisternum rufous; elytral disc rufobrunneous with purplish reflection due to transverse microsculpture; sutural interval paler, rufous basally, rufoflavous apically; elytral lateral margins rufoflavous, lateral marginal depression flavous inside dark margin; elytral apex broadly, slightly paler, rufoflavous; elytral epipleuron rufoflavous, metepisternum rufobrunneous with a piceous cast; abdominal ventrites 1-3 rufobrunneous, 4-6 paler, rufoflavous; metafemur rufoflavous with medial brunneous cloud; metatibia rufoflavous with brunneous cast.

Male Genitalia. (n = 1). Aedeagal median lobe narrowed dorsoventrally in apical half, apex dorsoventrally expanded to an adze-like tip (Fig. 4A), the apical face of tip much less convex than dorsal and ventral margins; flagellar plate large, length 0.5 × distance from parameral articulation to apical face of tip; right paramere extended to 0.8 × distance from parameral articulation to apical face, left paramere extended nearly to tip; internal sac with broad dense ventral microtrichial field, and small, lightly spinose dorsal ostial microtrichial patch (assessed in uneverted condition).

Female Reproductive Tract. (n = 1). Bursa copulatrix columnar, elongate, length 3 × maximum breadth in slide-mounted specimen (Fig. 5A); bursa membranous, lightly sclerotized based on amount of Chlorazol Black staining; spermatheca reniform, spermathecal gland duct long enough so that gland extends beyond apex of bursa; basal gonocoxite 1 with apical fringe of 2-3 setae, 6-7 smaller setae along mesal margin (Fig. 6A); apical gonocoxite 2 subacuminate, apex tightly rounded, basolateral area moderately expanded; 2 lateral ensiform setae, the apical seta stouter, 1 dorsal ensiform setae, and 2 apical nematiform setae.

Holotype male (MNHN), labeled: FRENCH POLYNESIA: Moorea / Toheia, off trail beneath ridge / 26-ix-2009 el. 1145 m C. Ewing/-17.55152 -149.82147 pyr. fog / unknown tree MBIO6551 // HOLOTYPE / Mecyclothorax / perraulti / J.K. Liebherr 2012 (black-bordered red label)

Allotype female (MNHN), labeled: FRENCH POLYNESIA / Moorea Tohiea summit / 12-IX-2006 lot 07 / S17°33.03', W149°49.33' / el. 1150-1200 m beating / flowering Myrsine after / dark J.K. Liebherr // ALLOTYPE / Mecyclothorax / perraulti / J.K. Liebherr 2012 (black-bordered red label)

Other paratypes.

SOCIETY ISLANDS. Moorea: Tohiea summit, 1120 m el., S17°33.07', W149°49.38', 12-ix-2006 lot 05, beating rotten Freycinetia and ferns, Liebherr (CUIC, 1); 1097 m el., S17°33.05', W149°49.28', 13-ix-2006 lot 02, Berlese extraction of fern litter, Ewing (CUIC, 1); muddy gulch on trail, 1170 m el., S17°33.08', W149°49.31', 25-ix-2009, pyrethrin fog mossy tree, MBIO 5853, Ewing (EMEC, 1).

Etymology.

This species epithet honors the memory of Georges G. Perrault, the principal describer and reviser of the Tahitian Mecyclothorax fauna.

Distribution and habitat.

Individuals of this species have been found from the summit at 1207 m elevation down to 1100 m. Specimens have been found microsympatrically in rotten Freycinetia stalks with Mecyclothorax mapo , and in association with Mecyclothorax mapo and Mecyclothorax fatata on flowering Myrsine at night, and in a pyrethrin fog sample of a mossy tree trunk. An individual of this species was the lone carabid beetle recovered from a Berlese extraction sample of leaf litter taken at 1100 m.