Mecyclothorax pahere, 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 : 47-49

Mecyclothorax pahere sp. n.

Diagnosis.

This species plus Mecyclothorax altiusculus , Mecyclothorax pseudaltiusculus Perrault, and Mecyclothorax paraltiusculus Perrault share a bisetose, trapezoidal pronotum with rounded hind angles, and a setal formula of 2122, however individuals of this new species are larger; standardized body length 7.5-7.9 mm. The pronotum is also more transverse; MPW/PL = 1.35-1.36 (n = 2). The striae are deep and distinctly punctate in their basal half, and the convex intervals are covered with dense transverse microsculpture consisting of a mixture of parallel transverse lines and transverse-mesh sculpticells 2 –4× broad as long. The mesal face of the male metatibia is lined with pectinate swellings at the points of articulation of the mesal longitudinal setal series (Fig. 2B). Of the three species listed above, Mecyclothorax paraltiusculus is most similar, attaining a similar body size-7.0 mm-and possessing elytral microsculpture consisting of a mixture of transverse lines and transverse mesh.

Description.

Head capsule withbroad, shallow frontal grooves, the frontal surface transversely wrinkled between the grooves, and a broad, low convexity bordering the groove mesad the anterior supraorbital seta; dorsally the head capsule is flat from the frons to the pronotum; ocular lobe moderately prominent and largely covered by eyes, the posterior portion of lobe obtusely joined to gena, the juncture marked by fine, shallow groove; ocular ratio 1.47, ocular lobe ratio 0.79-0.83; labral anterior margin broadly emarginate 0.2 × length; antennomeres glabrous except for apical setae; antennae elongate filiform, antennomere 8 length 3 × greatest width; mentum tooth with sides defining an acute angle, the apex rounded. Prothorax transverse, the basolateral margins straight to slightly concave due to the upcurved margin anterad the rounded hind angles, MPW/BPW = 1.55-1.60 (n = 2); median base slightly depressed medially, moreso laterally, with more than 40 small punctures each side; basal margin broadly, slightly convex between laterobasal depressions; median longitudinal impression obsolete but traceable on disc, present as a lenticular depression at front of median base; anterior transverse impression deep, finely incised, with 7-8 elongate punctures each side bordered by longitudinal carinae that span impression from disc to anterior callosity; anterior callosity moderately convex, covered with indistinct longitudinal wrinkles; front angles protruded, broadly rounded, APW/BPW = 0.95-0.96 (n = 2); lateral marginal depression broadly explanate, translucent, edge upturned anteriorly, more beadlike near lateral seta; laterobasal depression a broadened continuation of the lateral depression, surface punctured as median base, deepest portion meeting posterior margin at lateral edge of basal margin convexity; proepisternum with 7 distinct punctulae along hind margin, ~10 smaller punctures along posterior marginal bead of proepimeron; prosternal process broad, slightly depressed anteriorly between coxal cavities, convex posterad at juncture with posterior face. Elytra broad, subquadrate, MEW/HuW = 2.32-2.35 (n = 2); disc convex medially, sides sloped to nearly vertical; basal groove moderately curved to subangulate humerus, elytral margin at humerus only slightly upraised; parascutellar seta present; parascutellar striole defined by 4 separated punctures, the striole depressed between punctures; sutural intervals elevated to meet at suture, only slightly more convex than distinctly convex discal intervals; striae 1-8 deep, finely impressed, and distinctly punctate in basal half; all striae deep and smooth at elytral apex; eighth interval upraised in a narrow bulbous carina laterad subapical seta, the interval’s outer face nearly vertical; 2 dorsal elytral setae (one individual with 3 setae on one elytron) positioned at 0.22 × and 0.52 –0.60× elytral length (asymmetrical third seta at 0.75 × elytral length), each seta within evident depressions that span ⅔ width of interval 3; both apical and subapical elytral setae present; lateral elytral setae 7 + (5-6); elytral marginal depression moderately broad throughout length, translucent, reduced to beadlike margin only just anterad abruptly concave subapical sinuation. Mesepisternum distinctly punctate anteriorly, ~19 deep punctures in 2-3 rows; metepisternum short, width to length ratio 0.87; metepisternal-metepimeral suture varied, a distinct suture in one individual, an indistinct, broad depression in the second; metathoracic flight wing an elongate straplike vestigium, length 4 × width, and apical ¼ of wing length surpassing hind margin of metathorax, rudimentary R and M veins evident. Abdomen with irregular wrinkles on visible ventrites 1-4, and indistinct round depressions laterally on ventrites 4-6; suture between visible ventrites 2 and 3 complete. Legs with metatarsomere 1 moderate, length 0.19 × length of metatibia; metatarsomere 4 with short apical lobes, maximal tarsomere length 1.2 × median tarsomere length; metatarsomere 4 with very short subapical setae and longer apical setae; metatarsal dorsolateral sulci very shallow, obsolete, dorsum broadly convex. Microsculpture on frons and vertex a transverse mesh, sculpticell breadth 2 × length; pronotal disc with obsolete microsculpture, indistinct transverse mesh with sculpticells 3 –4× broad as long visible near edge of light reflections; pronotal median base with evident transverse-mesh microsculpture between punctures, sculpticell breadth 2 –3× length; elytral disc covered with a mixture of transverse lines and transverse mesh with sculpticell breadth 2 –4× length; elytral apex covered with transverse mesh, sculpticell breadth 2 –4× length; metasternum glossy with obsolete transverse sculpticells; laterobasal abdominal ventrites glossy with shallow, swirling isodiametric and transverse mesh sculpticells. Coloration of frons and vertex piceous; antennomeres 1-4 rufoflavous to brunneous, segments 5-11 slightly darker; pronotal disc rufopiceous with metallic silvery reflection; reflexed pronotal margins translucent brunneous; proepipleuron rufo-brunneous, proepisternum rufopiceous; elytral disc rufopiceous with cupreous reflection; sutural interval concolorous basally, rufous apically; reflexed elytral margin brunneous, elytral apex narrowly, indistinctly paler, brunneous; elytral epipleuron rufobrunneous, metepisternum rufopiceous; abdominal ventrites glossy rufopiceous, apical ventrite narrowly rufobrunneous; metafemur and metatibia rufobrunneous.

Male genitalia. (n = 1). Aedeagal median lobe broadest dorsoventrally near midlength, apex hooklike, with small dorsal toothlike expansion (Fig. 4B); median lobe curved to right in ventral view (Fig. 4C), the apex elongated beyond apical margin of ostium; internal sac with well-developed dorsal and ventral ostial microtrichial patches; flagellar plate moderately large, length 0.3 × distance from apex to parameral articulation; parameres broad basally, right paramere extended 0.7 × distance from parameral articulation to apex (Fig. 4B), left paramere longer, extended 0.9 × distance to apex (Fig. 4C).

Female reproductive tract. (n = 1). Bursa copulatrix columnar, heavily sclerotized, the surface leathery, bursal length 2 × maximal width in slide-mounted dissection (Fig. 5B); spermathecal duct entering on dorsal bursal wall apicad position along length of bursal juncture with common oviduct; spermathecal gland duct short, little longer than spermatheca, the glandular reservoir elongate and gradually widened in diameter from duct; basal gonocoxite 1 with 3-4 apical fringe setae, and 8-10 setae along ventromesal margin (Fig. 6B); apical gonocoxite 2 broad basally with narrow, acuminate tip, and 2-3 lateral ensiform setae, 1 dorsal ensiform seta, and 2 apical nematiform setae.

Holotype male (MNHN), labeled: FRENCH POLYNESIA: Moorea / Tohiea, muddy gulch along trail / 24-ix-2009 el. 1150 m C. Ewing / -17.55130 -149.82178 pyr. fog / mossy tree trunk MBIO 5860 // HOLOTYPE / Mecyclothorax / pahere / J.K. Liebherr 2012 (black-bordered red label).

Allotype female (MNHN), labeled: FRENCH POLYNESIA: Moorea / Tohiea, muddy gulch along trail / 25-ix-2009 el. 1150 m C. Ewing / -17.55130 -149.82178 pyr. fog / mossy tree trunk MBIO 5859 // ALLOTYPE / Mecyclothorax / pahere / J.K. Liebherr 2012 (black-bordered red label).

Etymology.

The species epithet is the Tahitian word pahere, or comb in English, either the noun or verb form (Wahlroos, 2002), and being indeclinable, is to be treated as a noun in apposition. The name is indicative of the metatibial comb in the male, formed by the evaginated bosslike articulatory processes associated with with the mediolongitudinal series of tibial setae.

Distribution and habitat. The allotype female was collected in a pyrethrin fog sample from a mossy tree trunk along with one individual each of Mecyclothorax fatata and Mecyclothorax mapo . The holotype male comprised the only beetle collected in a similar situation the day earlier.