Mecyclothorax fatata, 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 : 59-61

Mecyclothorax fatata sp. n.

Diagnosis.

This species shares upturned pronotal margins with a visible lateral depression (Fig. 3D) and regular transverse–mesh elytral microsculpture with Mecyclothorax ata Perrault. Individuals of the two species are of similar body size; standardized body length 4.7-5.0 for this species versus 4.5 mm for Mecyclothorax ata . However this species deviates from Mecyclothorax ata by presence of only the anterior elytral seta resulting in a setal formula of 2211 versus 2221 for Mecyclothorax ata . The pronotal base is also more constricted in this species, MPW/BPW = 1.53-1.62 (n = 5) versus a ratio of 1.49 in Mecyclothorax ata ( Perrault 1986).

Description.

Head capsule gracile, elongate, frontal grooves subparallel at thin carina posteriorly, mesad anterior supraorbital seta, convergent anterad, clypeo–ocular prolongation broadly convex, frons between groove densely covered with fine transverse wrinkles; dorsum of head flat on frons in lateral view, neck convex; ocular lobe protruded, posterior portion meeting gena at broad, moderately deep groove; compound eye slightly protruded from ocular lobe, slightly convex dorsally laterad supraorbital seta, more than 20 ommatidia along diameter defined by lower margin of antennal articulatory socket; ocular ratio 1.48-1.60, ocular lobe ratio 0.79-0.86; labral anterior margin broadly shallowly emarginate ¹�₉ length; antennomeres 1-3 mostly glabrous except for apical seta, antennomere 3 with a few very short setae on posterior surface of shaft; antennae moderately elongate, antennomere 8 length 1.8 × maximum breadth; mentum tooth sides defining an acute angle, apex tightly rounded. Pronotum smoothly cordate, basolateral margins nearly subparallel anterad rounded obtuse hind angles, distinctly divergent just anterad basal pronotal setae; pronotum somewhat transverse, MPW/PL = 1.15-1.20 (n = 5); median base distinctly depressed relative to disc, punctures arrayed along margin of base and disc, 13-14 punctures of various sizes each side; basal margin slightly convex between laterobasal depressions; median longitudinal impression very fine and shallow but complete on disc, prolonged as longitudinal crease on median base; anterior transverse impression broad and shallow, smooth, finely incised only mesad front angles; anterior callosity flat, little upraised, densely covered with shallow longitudinal wrinkles; front angles very slightly protruded anterad, broadly rounded, distances between front and hind angles subequal, APW/BPW = 0.99-1.05 (n = 5); lateral marginal depression bordered by upraised lateral margin at lateral pronotal seta, broader with margin less upraised at front angle, broader basally joining laterobasal depression which is broader, the surface irregularly punctured; proepisternum with 7 distinct punctulae along hind margin, proepimeron with about 10 very small punctures along marginal collar; prosternal process narrowly depressed medially, sides broadly upraised between procoxae, surface convex posterad at juncture with posterior face. Elytra ellipsoid, humeri proximate, disc convex medially, surface sloping laterally to near vertical juncture with lateral marginal depression; basal groove briefly curved to angulate humerus, MEW/HuW = 2.43 -2.67 (n = 5); parascutellar seta present; parascutellar striole 3-4 punctate, surface not depressed between punctures; sutural intervals elevated to meet at suture, more convex, callouslike apically; striae 1-6 punctate, the punctures expanding strial width, but striae shallow between punctures, and striae progressively shallower laterally, stria 7 obsolete, indicated by irregularly evident shallow, longitudinal punctulae; intervals on disc flat; sutural stria 1 and stria 7 deep, well defined at apex, striae 2-6 very shallow, difficult to trace; mesal margin of interval 8 protruded as a distinct carina apicad the subapical sinuation; anterior dorsal elytral setae in small impression spanning ½ of interval 3, the setae situated at 0.25 –0.26× elytral length; apical elytral seta present, subapical seta absent; lateral elytral setae 7 + 6; elytral marginal depression moderately narrow, edge upturned at humerus, depression broader and edge more upturned laterally to elytral midlength, then depression narrowed, margin beadlike anterad subapical sinuation; subapical sinuation very shallow and brief, nearly obsolete. Mesepisternum with single dorsoventral row of 5-6 large punctures; metepisternum moderately elongate, width to length ratio 0.68; metepisternum separated from metepimeron by distinct suture; metathoracic flight wing vestigium an elongate strap, length 3 × width, the apical half of strap extended beyond hind margin of metanotum, with rudiments of wing veins C, R, M, and Cu visible in vestigium. Abdomen with visible ventrites 1-4 irregularly wrinkled laterally, ventrites 3-6 with rounded depressions laterally; suture between visible ventrites 2 and 3 effaced laterally. Metatarsomere 4 emarginate apically, short apical lobes present, overall tarsomere length 1.5 × median tarsomere length; metatarsomere 4 with long apical and very short subapical setae that are situated along dorsal margin of tarsal apical lobes; metatarsal dorsolateral sulci shallow and lateral, tarsomere dorsum broad, nearly flat. Microsculpture on frons a regular transverse mesh, sculpticell breadth 2 –3× length, neck with isodiametric sculpticells in transverse rows; pronotal disc with a mixture of transverse lines and transverse mesh with sculpticell breadth 3 –4× length, the surface subiridescent due to microsculpture; pronotal median base covered with dense, swirling isodiametric and transverse sculpticells between punctures; elytral disc with distinct transverse mesh, sculpticell breadth 2 –4× length, the surface subiridescent; elytral apex with transverse mesh, sculpticells 2 –4× broad as long, the sculpticells slightly upraised; metasternum with distinct elongate transverse mesh; laterobasal abdominal ventrites with glossy surface, swirling isodiametric and transverse sculpticells plainly visible. Coloration of head capsule rufobrunneous with a piceous cast; antennomeres 1-2 flavous, 3-11 rufoflavous; pronotal disc rufobrunneous with silvery metallic reflection, lateral margins, base and anterior callosity darker than disc, with piceous cast; proepipleuron rufoflavous, proepisternum rufobrunneous; elytral disc rufobrunneous with silvery reflection; sutural interval concolorous with disc basally paler, rufoflavous apically; elytral marginal depression concolorous with disc at humerus, depressed area rufoflavous from midlength to subapical sinuation; elytral epipleuron rufoflavous, metepisternum rufobrunneous; abdomen rufobrunneous, broadly paler apically to rufoflavous apex of visible ventrite 6; metafemur rufoflavous; metatibia rufoflavous with brunneous cast.

Male genitalia. (n = 2). Aedeagal median lobe of equal diameter in basal ⅔ of length, narrowed to a bluntly rounded, ventrally expanded apex (Fig. 4H); internal sac with melanized microspicules on surface, appearing dark in uneverted dissection; flagellar plate large, melanized, length 0.5 × distance from parameral articulation to apex; right paramere narrowly elongate, apex extended 0.85 × distance from parameral articulation to apex, left paramere longer, apex extended 0.90 × such distance.

Female reproductive tract. (n = 1). Bursa copulatrix columnar, length 2.4 × greatest width in microslide–mounted dissection (Fig. 5E), bursal surface lightly sclerotized based on staining with Chlorazol Black; spermatheca reniform, spermathecal duct thin and lighly sclerotized; spermathecal gland bulbous, apparently filled with material that did not clear in 10% KOH in dissected individual, attached to spermatheca by short duct; basal gonocoxite 1 with apical fringe of 4 setae (Fig. 6E), 13-14 small setae arrayed across medial portion of coxite; apical gonocoxite 2 broad basolaterally, the lateral margin broadly excavate, the apex subacuminate; 2 lateral and 1 dorsal ensiform setae, and 2 apical nematiform setae present.

Variation. Marginal setation of the apical visible ventrite in males is unstable in this species. Of the four male specimens, one individual has 4 terminal abdominal setae along the apical margin of visible ventrite 6, 2 on each side (EMEC); one has 3 apical setae, 1 on the right and 2 on the left (CUIC); and two others exhibit the usual 2 setae, 1 each side (MNHN, EMEC).

Holotype male (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 // HOLOTYPE / Mecyclothorax / fatata / 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, 2); 1125 m el., S17°33.07', W149°49.38', 12 –ix– 2006 lot 02, pyrethrin fog Weinmannia , moss + roots, Liebherr (CUIC, 1); summit along ridge to west, 1190-1207 m el., S17°33.04', W149°49.34', 24 –ix– 2009, beating Myrsine , MBIO 5857, Ewing (EMEC, 1); muddy gulch on trail, 1170 m el., S17°33.08', W149°49.31', 25 –ix– 2009, pyrethrin fog mossy tree, MBIO 5853, Ewing (CUIC, 1); 1150 m el., S17°33.08', W149°49.31', 25 –ix– 2009, pyrethrin fog mossy tree trunk, MBIO 5859, Ewing (EMEC, 1).

Etymology.

Because this species is most similar to Mecyclothorax ata , the Tahitian epithet fatata, near or nearly ( Wahlroos 2002) was chosen to express the similarity. The epithet is indeclinable and is to be treated as a noun in apposition.

Distribution and habitat.

All six collections and eight specimens of Mecyclothorax fatata were made in association with the numerically dominant Mecyclothorax mapo . In two instances Mecyclothorax perraulti was also present in the sample. Five of the eight Mecyclothorax fatata specimens were collected from Myrsine , one from moss–covered Weinmannia , and two others from unidentified trees.