Mecyclothorax paniensis Liebherr, 2018

Liebherr, James K., 2018, Cladistic classification of Mecyclothorax Sharp (Coleoptera, Carabidae, Moriomorphini) and taxonomic revision of the New Caledonian subgenus Phacothorax Jeannel, Deutsche Entomologische Zeitschrift 65 (1), pp. 1-63 : 34-36

12. Mecyclothorax paniensis Liebherr sp. n. Figures 17K-L , 18F , 20B , 23B , 24B , 25

Diagnosis.

These beetles can be diagnosed by the parallel lateral margins at the base of the pronotum, resulting in very slightly obtuse hind angles that protrude laterally (Fig. 20B ). The elytral striae are much reduced, with the sutural striae only evident basally where it comprises a series of shallow, disconnected, elongate depressions. The elytra are broadly ovoid, with the humeri very reduced, with the elytral basal groove angulate posterad the protruded pronotal hind angles. Standardized body length 3.5-4.1 mm. Chaetotaxy +/+//+/-//+/2/+/+.

Description

(n = 5). Head capsule elongate, eyes small, convex, ocular lobe-genal juncture evenly curved, a very shallow groove indicating limit of ocular lobe; 14 ommatidia along horizontal diameter of eye; ocular ratio 1.35-1.42, ocular lobe ratio 0.77-0.82, EyL/EyD = 2.0-2.49; frontal grooves narrowly incised, straight and convergent to deepest portion at frontoclypeal suture, deeply extended onto clypeus; mandibles moderately elongate, mandibular ratio 1.71; ligular anterior margin narrowly rounded, the two ligular setae separated by one to two setal diameters; paraglossae thin, extended twice as far beyond ligular margin as their basal length to margin; antennae elongate, antennomere 9 length 2.62 × maximal breadth; antennomere 3 glabrous except for apical ring of setae. Pronotum distinctly cordate, lateral margins slightly convergent anterad protruded, obtusely-angulate hind angles, the lateral margin immediately divergent anterad subparallel lateral margins at pronotal base (Fig. 20B ), MPW/BPW = 1.83-1.88, MPW/PL = 1.13-1.26; front angles slightly protruded, obtuse, APW/BPW = 1.11-1.16; median base unmargined basally, trapezoidally depressed relative to disc, the median longitudinal impression divided basally into two transverse impressions that isolate disc from base, each transverse basal impression terminated laterally in a longitudinally arcuate laterobasal depression; median longitudinal impression finely incised on disc, terminated anteriorly just anterad anterior transverse impression, a lenticular fovea at posterior juncture with basal transverse impressions; anterior transverse impression shallow, broad, intermittently traceable to front angles; proepisternum separated from prosternum by a shallow groove anteriorly, and deep, distinct groove ventrally; smooth anteapical impression well developed laterally, continuous though shallower ventrally; prosternal process broadly depressed between procoxae, that depression extended 1/2 distance toward anterior prothoracic margin, the depression broadest at its anterior terminus. Elytra broadly ovoid, humeri extended laterally before sloping posteriorly laterad distinct, obtuse humeral angle; MEW/EL = 0.80-0.88; all striae reduced on disc, sutural and fourth stria most evident, but intervening intervals flat; sutural stria distinctly impressed apically to complement deep stria 8; elytra appressed and conjoined apically, the sutural margin upraised at apex. Pterothoracic mesepisternal anterior furrow with 2-3 irregular pits in deepest portion of furrow; mesosternal-mesepisternal suture complete (as in Fig. 3A ); metepisternum slightly longer than broad, maximum width/lateral length = 0.92; metepisternal-metepimeral suture complete. Abdomen with broad crescent-shaped depression along suture between first and second ventrite, second ventrite only slightly depressed within crescent; suture between second and third ventrites reduced though traceable laterally; ventrites 2-6 with broad, shallow, linear to circular plaques near lateral margin. Microsculpture of frons reduced, surface glossy, indistinct transverse mesh visible over portions of vertex; pronotal disc glossy but with transverse sculpticells, breadth 4 × length, and transverse lines over surface, trapezoidal median base with transverse sculpticells, breadth 3 × length visible in areas of no reflection; elytra distinctly iridescent, disc covered with transverse lines, elytral apex covered with elongate transverse sculpticells and lines.

Male genitalia (n = 1). Antecostal margin broadly angulate, not extended (Fig. 17L ); right paramere narrow basally, apical half narrowed into a narrow whiplike extension, its ventral surface bearing 15 setae near midlength distant from elongate pair of apical setae (Fig. 18F ); left paramere narrow basally, evenly narrowed to a whiplike apex, two apical setae present; aedeagal median lobe robust, broad dorsoventrally, the ventral and dorsal margins evenly curved to a broadly rounded apex that extends moderately beyond ostial opening (Fig. 17K ); aedeagal median lobe internal sac with elongate flagellum and flagellar sheath plus dorsal plate.

Female reproductive tract (n = 1). Bursa copulatrix length slightly greater than circumference, its surface thin, translucent, not wrinkled (Fig. 23B ); spermathecal duct entering near bursa-common oviduct juncture with duct oriented toward right side of bursa, duct length twice length of spermathecal reservoir; knoblike helminthoid sclerite present at base of spermathecal duct; spermatheca fusiform on narrow duct, spermathecal gland duct entering at base of spermathecal reservoir; ligular apophysis present on common oviduct; basal gonocoxite 1 with apical fringe of two setae laterally and several smaller setae medially, a series of small setae lining medial margin (Fig. 24B ); gonocoxite 2 moderately broad basally, basal width half medial length; two gracile lateral ensiform setae of moderate length present, the apical seta slightly broader.

Types - Holotype male (MNHN): NEW CALEDONIA / Mt Panie summit / Nov 2001 / C. Burwell // QM Berlesate 1058 / 20°34 ’Sx164°46’ / Rainforest, 1600m / Sieved litter // QUEENSLAND / MUSEUM LOAN / DATE: Sept 2002 No. LE 02.43 (green label) // HOLOTYPE / Mecyclothorax / Mecyclothorax paniensis / J.K.Liebherr 2017 (black-bordered red label).

Paratypes (11 specimens). NEW CALEDONIA: Mt. Panié, 20°34'S 164°46'E, 08-x-1977, J. Balogh (HNHM, 1), 1300-1600 m, 15-v-1984, Monteith & Cook (QMB, 1), E trail, 1350-1629 m el., 20°35.3'S 164°46.2'E, rainforest, 24-xi-2010, Wanat & Ruta (MNHW, 3), refuge, 1300 m el., 20°34'S 164°46'E, rainforest, sieved litter, 8-9-xi-2001, lot 1056, Burwell (QMB, 2), summit, 1600 m el., 20°34'S 164°46'E, rainforest, sieved litter, xi-2001, lot 1058, Burwell (QMB, 2), summit, 1600, 20°35'S 164°46'E, 18-xi-2000, 9939, Bouchard, Burwell & Monteith (QMB, 2).

Etymology.

The adjectival ending -ensis is elided with the type locality Mt. Panié to obtain the species epithet Mecyclothorax paniensis , an adjective in the genitive case.

Distribution and habitat.

This species’ distribution is restricted to Mt. Panié (Fig. 25 ). Collecting localities are in the higher reaches of the mountain, 1300-1629 m elevation, with recorded microhabitats or collecting situations including rainforest and sieved litter. As such it appears beetles of this species occupy the ground-level litter layer.

Figures

Figure 3. Thoracic structures of Mecyclothorax spp. A-B. Lateral view of elytral epipleuron and meso-and metapleurites: A, M. laterorectus; B, M. fleutiauxi. C-D. Metathoracic flight wing: C, M. punctipennis, showing fully developed flight wing folded under elytron; D, M. lissus, stenopterous wing rudiment that extends beyond metanotum, rudimentary wing venation present at base of strap. Abbreviations include: mms, mesepisternal-mesosternal suture; msp, mesepimeron; mst, mesepisternum; mtp, metepimeron; mtt, metepisternum.

Figure 17. Male aedeagal median lobe and parameres, and ring sclerite-mediotergite plus antecostal margin, tergite IX-of Mecyclothorax (Phacothorax) spp.: A-B, M. plurisetosus, right view, dorsal view in situ (Aoupinie); C-D, M. megalovatulus, right view, dorsal view of righ sclerite (Mt. Panie); E-F, M. octavius, right view, dorsal view in situ (Me Maoya); G-H, M. laterovatulus, right view, dorsal view in situ (Aoupinie); I-J, M. manautei, right view, dorsal view in situ (Mt. Humboldt, 1400 m); K-L, M. paniensis, right view, dorsal view in situ (Mt. Panie); M-N, M. mouensis, right view, dorsal view in situ (Mt. Mou). See Table 2 for abbreviations.

Figure 18. Paired left (above) and right (below) parameres of Mecyclothorax (Phacothorax) spp. (ectal view): A, M. plurisetosus; B, M. megalovatulus; C, M. octavius; D, M. laterovatulus; E, M. manautei; F, M. paniensis; G, M. mouensis.

Figure 20. New Caledonian Mecyclothorax (Phacothorax) spp., dorsal view: A, M. manautei; B, M. paniensis; C, M. mouensis; D, M. kanak (Mt. Humboldt, 580 m); E, M. kanak (Mt. Humboldt, 630 m); F, M. kanak (Mt. Dzumac); G, M. kanak (Col de Yate); H, M. picdupinsensis.

Figure 23. Female reproductive tract, gonocoxites and associated laterotergites, Mecyclothorax (Phacothorax) spp: A, M. manautei; B, M. paniensis; C, M. mouensis; D, M. kanak (Mt. Dzumac; common oviduct artificially darkened to show configuration); E, M. kanak (Pic du Grand Kaori); F, M. picdupinsensis. See Table 2 for abbreviations.

Figure 24. Left female gonocoxa of Mecyclothorax (Phacothorax) spp., ventral view: A, M. manautei; B, M. paniensis; C, M. mouensis; D, M. kanak; E, M. picdupinsensis. See Table 2 for abbreviations.

Figure 25. Geographical distributions of Mecyclothorax (Phacothorax) spp. (asterisked locality attributed to M. mouensis based on non-type female specimen).