Mecyclothorax curtisi, Liebherr, James K., 2013

Liebherr, James K., 2013, The Mecyclothorax beetles (Coleoptera, Carabidae, Moriomorphini) of Tahiti, Society Islands, ZooKeys 322, pp. 1-170 : 58-60

48. Mecyclothorax curtisi sp. n.

Diagnosis.

Unique among the Mecyclothorax striatopunctatus group in the orbicular pronotum with broad pale margins, and the obovate elytra with pale, broadly explanate lateral marginal depressions (Fig. 28C). Setal formula 2221; standardized body length 5.4 mm. Head with deep frontal grooves, narrow behind and depressed mesad a low carina inside anterior supraorbital seta, sinuous toward midline at midlength, and broad, shallow near frontoclypeal suture; eyes moderately convex but small in diameter, ocular ratio 1.50, ocular lobe distinctly expanded from gena, ocular lobe ratio 0.80; antennae moderately elongate, filiform, eighth anennomere length 2.0 × maximal breadth. Pronotum transverse, MPW/PL = 1.31, orbicular, with broadly rounded hind angles and convex basal margin; basal pronotal setae expanding lateral margin, causing minute jag in margin, the seta and jag set 0.12 × pronotal length anterad the pronotal basal margin at the midline; median base with four shallow, isolated punctures each side and 7-8 longitudinal wrinkles at juncture with disc; anterior transverse impression broad, shallow, complete medially, crossed by 10-11 fine wrinkles in median quarter of each side; front angles broadly rounded, little protruded anteriorly, the lateral marginal depression gradually widened posterad to base, laterobasal depression defined by a U-shaped depression that is continuous with the lateral depression surrounding a low, irregular tubercle. Elytra narrow basally, MEW/HuW = 2.67, the basal groove distinctly recurved anteriorly to the subangulate humerus; parascutellar seta on papillate dome that is bordered behind by a depression connecting parascutellar striole and interval 1; disc depressed across first four intervals each side directly posterad the inflated parascutellar striole; flat lateral marginal depression gradually widened with margin more upraised posterad humerus, achieving maximal breadth near posterior seta of anterior lateral elytral setal series; discal elytral striae 1-6 deep, set with distinct elongate punctures that expand the strial breadth in a crenulate pattern; stria 7 shallow, finely inscribed, punctures isolated, especially apically; eighth elytral interval upraised above striae 7 from anterad subapical sinuation to apex, tightly convex, looking pinched laterally dorsad subapical sinuation; lateral elytral setae 7 + 1 + 5 (left) and 7 + 6 (right) of unique holotype. Metathoracic wings stenopterous straps 4 × long as wide, margins parallel in apical half, apex narrowly rounded; alae with distinct Sc+R and M veins present, and indistinct wrinkles in cubital region of wing rudiment. Microsculpture of head a distinct transverse mesh visible across frontal grooves, frons, and vertex; pronotal disc covered with well-developed transverse mesh, the sculpticell pattern influenced by wrinkles radiating from the disc center, sculpticell breadth 3 –4× length; discal elytral intervals with regular transverse mesh, sculpticell breadth 2 –3× length, with some isodiametric sculpticells intermixed. Coloration of head a uniform rufobrunneous; antennomere 1 flavous, each antennomere 2-11 rufobrunneous basally, rufoflavous apically; pronotal disc rufobrunneous to match head color, lateral marginal depression rufoflavous, palest at front angle; elytral disc flavobrunneous, paler than head and pronotal disc; elytral lateral marginal depression concolorous with disc at humerus, paler apically all the way to subapical sinuation; femora brunneous with flavous apex, tibiae flavous with brunneous cast. Male abdomen with extra transverse, arcuate fold near midlength of visible abdominal ventrite 6, resulting in a partially formed ventrite 7; two smaller setae at apical margin of pseudosegment 6, in line with accessory setae of ventrites 3-5; apical margin of pseudosegment 7 with the usual two apical setae at lateral quarter of breadth each side.

Male genitalia. Aedeagal median lobe only moderately curved, ventral surface of shaft straight apicad parameral articulations (Fig. 27G); median lobe apex short, rounded, slightly more expanded on dorsal margin; ostial canal starting on ride side of lobe apex, terminated closer to dorsal margin; flagellar plate elongate, length ~0.50 × distance from parameral articulations to apical face; right paramere slightly broadened, parallel sided from base to tightly rounded apex.

Holotype male (MNHN) labeled: French Polynesia: Tahiti Iti / Mts. Teatara summit / 1195 m el. 17-IX-2006 lot 10 / 17°47.907'S, 149°14.183'W / pyr. fog Astelia on mossy / log C.P. Ewing // HOLOTYPE / Mecyclothorax / curtisi / J.K. Liebherr 2013 (black-bordered red label).

Etymology.

The patronymic species epithet curtisi honors the collector, Dr. Curtis P. Ewing, who collected extensively at the summit of Mont Teatara, one of several inaccessible French Polynesian peaks he has worked hard to explore.

Distribution and habitat.

The holotype and only known specimen was collected at 1195 m elevation at the summit of Mont Teatara, Tahiti Iti. The specimen came from a pyrethrin fog sample of a horizontal mossy log with an epiphytic Astelia plant growing on it.