Mecyclothorax megalovatulus 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 : 26-28

publication ID	https://dx.doi.org/10.3897/dez.65.21000
publication LSID	lsid:zoobank.org:pub:73DEE0F3-2BB0-4A21-B445-5E168FE50F54
persistent identifier	https://treatment.plazi.org/id/75E12733-B4D0-463E-957C-368853BD124C
taxon LSID	lsid:zoobank.org:act:75E12733-B4D0-463E-957C-368853BD124C
treatment provided by	Deutsche Entomologische Zeitschrift by Pensoft
scientific name	Mecyclothorax megalovatulus Liebherr
status	sp. n.

Treatment

7. Mecyclothorax megalovatulus Liebherr sp. n. Figures 12G View Figure 12 , 13G View Figure 13 , 16B View Figure 16 , 17C-D View Figure 17 , 18B View Figure 18 , 19 View Figure 19

Diagnosis.

This and the following species, M. octavius , can be diagnosed by their large body size; in this species standardized body length = 5.4-5.8 mm. Individuals of this species have the elytral striae well developed, with striae 1-8 deep and continuous throughout their length (Fig. 16B View Figure 16 ) in contrast to the obsolete striae and smooth elytra of M. octavius (Fig. 16 C View Figure 16 ). The elytra are narrowly ellipsoid with very narrow humeri. The pronotal hind angles are obtuse but rounded at the apex of the angle, and the pronotal base is unmargined. Chaetotaxy +/+//+/-//+/2/+/+.

Description

(n = 4). Head capsule trapezoidal, neck broad, eyes broad and little convex, ocular lobe meeting gena at very obtuse angle well behind eye posterior margin; 20 ommatidia along horizontal diameter of eye; ocular ratio 1.37-1.44, ocular lobe ratio 0.74-0.82, EyL/EyD = 2.81-2.86; frontal grooves narrow, well incised, sinuously convergent to just posterad clypeus, extended briefly onto clypeus; mandibles moderately elongate, mandibular ratio 1.83; ligular margin rounded to ligular seta, concave between the two setae, setae separated by one to two setal diameters; paraglossae thin, extended as far beyond ligular margin as half of basal length to margin; antennae elongate, antennomere 9 length 2.9 × maximal breadth; antennomere 3 glabrous except for apical ring of setae. Pronotum vase-shaped, narrow basally, lateral margins only slight concave anterad rounded hind angles, median base convex, not depressed relative to disc, without marginal bead (Fig. 16B View Figure 16 ); MPW/BPW = 2.56-2.83, MPW/PL = 1.21-1.28; front angles protruded, obtuse, pronotal apex distinctly broader than base, APW/BPW = 1.65-1.74; median longitudinal impression shallowly and very finely incised on disc, intermittently extended in front of evident anterior transverse impression, terminated posteriorly in deep ellipsoid pit situated medially between the anterior margins of laterobasal depressions; anterior transverse impression broad and shallow but easily traceable to front angles; laterobasal depressions flat, triangular, defined medially by a longitudinal crease laterad median base and anteriorly by a transverse crease bordering pronotal disc; proepisternum separated from prosternum by a shallow groove both anteriorly and ventrally; prosternum with well-defined anteapical impression laterally, the impression shallower though complete ventrally; prosternal process shallowly and broadly depressed between procoxae, prosternum medially flattened anterad procoxae with an ovoid pitlike depression medially about 1/3 distance to anterior prosternal margin. Elytra ellipsoid, broadest about midlength, humeri distinctly sloping posterad humeral angle; MEW/EL = 0.74-0.81; basal groove briefly extended laterad scutellum, four-punctate at bases of abbreviated parascutellar striole, sutural and striae 3 and 4; intervals 3 and 8 more convex than the others at elytral apex, though all intervals are at least moderately convex; elytra appressed and conjoined at apex , sutural intervals slightly narrowed there. Pterothoracic mesepisternal anterior surface smooth except for a vertical furrow ventrally near prosternum; mesosternal-mesepisternal suture incomplete, obsolete to absent near anterior margin of mesothorax (as in Fig. 3B View Figure 3 ); metepisternum very short, maximum width/lateral length = 1.73, metepisternal-metepimeral suture incomplete, obsolete laterally. Abdomen with distinct, well-defined crescent-shaped depression along suture between first and second ventrite, second ventrite little depressed posterad crescent; suture between second and third ventrites reduced though traceable laterally; ventrites 2-6 with broad, shallow, linear plaques near lateral margin. Microsculpture of frons and vertex a well-defined, transversely-stretched isodiametric mesh; pronotal disc and base with shallow transverse mesh, sculpticell breadth 3-4 × length, surface glossy, sculpticells arranged as a distinct transverse mesh in laterobasal depressions; elytral disc with shallow transverse lines, the surface glossy, subiridescent, the apex covered with indistinct transverse lines.

Male genitalia (n = 1). Antecostal margin of abdominal mediotergite IX angulate, broad and little distended (Fig. 17D View Figure 17 ); right paramere with broad base, apex elongate, narrowly extended and membranous, with two very short apical setae (Fig. 18B View Figure 18 ); left paramere broad basally, evenly narrowed in basal half to an elongate whiplike extension, two elongate setae apically; aedeagal median lobe robust, broad dorsoventrally, distinctly curved both dorsally and ventrally to a subparallel, extended apex, the tip of apex laterally curved into an apical hooklike crease (Fig. 17C View Figure 17 ); aedeagal internal sac with flagellum, flagellar sheath, and dorsal plate (Fig. 17C View Figure 17 ).

Female reproductive tract (n = 1). Bursa copulatrix elongate, length more than twice basal circumference, apical portion expanded laterally toward right, surface thick apically, wrinkled, densely stained relative to bursal base (Fig. 12G View Figure 12 ); spermathecal duct entering near bursa-common oviduct juncture with duct oriented toward right side of bursa, duct as long as spermathecal reservoir; a heavily sclerotized, triangular helminthoid sclerite present near base of spermathecal duct; spermatheca fusiform on narrow duct, spermathecal gland duct entering at base of spermathecal reservoir; ligular apophysis present near base of common oviduct; basal gonocoxite 1 with apical fringe of three setae situated near apicomedial angle, medial surface of gonocoxite 1 glabrous (Fig. 13G View Figure 13 ); gonocoxite 2 narrow basally, basal width about 2/3 medial length; two very gracile lateral ensiform setae present.

Types - Holotype male (MNHN): NEW CALEDONIA 8764 / 20°34 ’Sx164°46’ / Mt Panie refuge, 1300 m / 8-9Nov.2001.C.Burwell / Pyrethrum, trees & logs // QUEENSLAND / MUSEUM LOAN / DATE: Sept 2002 No. LE 02.43 (green label) // New Caledonia Mecyclothorax revision / measured specimen 3 / J.K. Liebherr 2016 ♂1 // genitalia in polyethylene vial with glycerine // HOLOTYPE / Mecyclothorax / Mecyclothorax megalovatulus / J.K.Liebherr 2017 (black-bordered red label).

Paratypes (3 specimens). NEW CALEDONIA: Mt. Panié, 1300-1600 m el., 20°35'S 164°46'E, 15-v-1984, Monteith & Cook (QMB, 1), refuge, 1300 m el., summit, 1600 m el., 20°34'S 164°46'E, rainforest, sieved litter, 9-xi-2001 lot 8769, Burwell (QMB, 1), track, 1500 m el., 20°34'S 164°46'E, pyrethrum trees & logs, 09-xi-2001, lot 8768, Burwell (QMB, 1).

Etymology.

Large body size and ovoid pronotum and elytra (Fig. 16B View Figure 16 ) suggested the compound adjectival epithet Mecyclothorax megalovatulus .

Distribution and habitat.

This species is only known from 1300-1600 m elevation on Mt. Panié, in the northern portion of the Chaîne Centrale (Fig. 19 View Figure 19 ). Three of the six specimens have been recovered from sieved litter, whereas one was collected via pyrethrin spray application to trees and logs, supporting occupation of ground-level litter as well as plant-based, mossy microhabitats.