Mecyclothorax laterorectus 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 : 19-21

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/B689EE86-804C-491D-8790-A6E9CAA437D3
taxon LSID	lsid:zoobank.org:act:B689EE86-804C-491D-8790-A6E9CAA437D3
treatment provided by	Deutsche Entomologische Zeitschrift by Pensoft
scientific name	Mecyclothorax laterorectus Liebherr
status	sp. n.

Treatment

3. Mecyclothorax laterorectus Liebherr View in CoL sp. n. Figures 1C View Figure 1 , 2A View Figure 2 , 2H View Figure 2 , 3A View Figure 3 , 9C View Figure 9 , 10F-H View Figure 10 , 11B View Figure 11 , 12C View Figure 12 , 13C View Figure 13 , 14 View Figure 14

Diagnosis.

This third of the species characterized by robust body and a cordate, broad-based pronotum with well-defined hind angles (Fig. 9A-C View Figure 9 ), can be diagnosed by the relatively narrower pronotal base: MPW/BPW = 1.37-1.40 (Fig. 2A View Figure 2 ). Like the immediately preceding M. laterosinuatus there are two supraorbital setae each side, and the pronotal lateral seta is present, but the discal elytral striae 3-5 are much shallower here, only slightly deeper than the shallow stria 2. The pronotal lateral margins are subparallel basally, with the pronotal hind angle obtuse, its apex not projected. Standardized body length 4.1-4.4 mm. Chaetotaxy +/+//+/-//+/2/+/+.

Description

(n = 5). Head capsule broad, eyes very convex, popeyed, ocular lobe meeting gena at obtuse angle close to eye posterior margin; 14 ommatidia along horizontal diameter of eye; ocular ratio 1.37-1.45, ocular lobe ratio 0.81-0.90, EyL/EyD = 2.56-2.89; frontal grooves nearly straight from posterior terminus inside anterior supraorbital seta to deepest point just posterad clypeus, briefly and shallowly extended onto clypeus; mandibles moderately elongate, mandibular ratio 1.7; ligular anterior margin narrowly rounded to ligular seta, concave between setae, the two setae separated by one to two setal diameters; paraglossae thin, extended as far beyond ligular margin as their basal length to margin; antennae moderately elongate, antennomere 9 length 2.0 × maximal breadth; antennomere 3 glabrous except for apical ring of setae. Pronotum distinctly constricted basally, cordate, hind angles protruded and nearly right, lateral margins distinctly, briefly sinuate anterad angles (Figs 2A View Figure 2 , 9B View Figure 9 ); MPW/BPW = 1.37-1.40, MPW/PL = 1.19-1.25; front angles only slightly protruded, rounded, APW/BPW = 0.72-0.77; basal margin broadly convex, margin broadly upraised behind broad laterobasal depression, the depression extended longitudinally onto disc as a broad sinuous furrow; median longitudinal impression fine and shallow on disc, continued to basal margin (a shallow transverse impression inside basal margin), absent anterad very shallow anterior transverse impression; proepisternum incompletely separated anteriorly from prosternum, but by a deep, smooth groove ventrally; prosternal process broadly, shallowly depressed between procoxae, that depression extended 1/3 distance to anterior prothoracic margin. Elytra broadly ellipsoid to obovoid, humeri narrow, humeral angle obtusely rounded behind pronotal hind angles; MEW/EL = 0.82-0.86; basal groove evenly arcuate from scutellum to humeral angles, with depressions at bases of the sutural and elytral striae 4-5; sutural stria deep throughout length, striae 2-3 shallow but evident on disc, striae 4-7 deep in basal half; striae 1-2, 7 and 8 evident apically, elytra appressed and conjoined apically, sutural intervals narrower and upraised at apex. Pterothoracic mesepisternal anterior furrow with 5 broad depressions in 1-2 vertical rows; metepisternum maximum width/lateral length = 1.0; mesosternal-mesepisternal suture complete (as in Fig. 3A View Figure 3 ); metepisternal-metepimeral suture incomplete, shallower and incomplete laterally. Abdomen with deep crescent-shaped depression along suture between first and second ventrite, the second ventrite depressed within crescent; suture between second and third ventrites reduced, incomplete laterally; ventrites 2-6 with broad, shallow, linear plaques near lateral margin. Microsculpture of frons an evident transverse mesh, transverse sculpticells mixed with isodiametric sculpticells on vertex; pronotal disc and base covered with elongate transverse mesh plus transverse lines, surface of tubercle in laterobasal depression with less transverse sculpticells, surface iridescent; elytra iridescent, disc with loose elongate transverse mesh, apex with very elongate transverse mesh, sculpticell breadth 3-4 × length. Femora rufobrunneous basally, with a broad flavous band in apical third.

Male genitalia (n = 3). Antecostal margin of abdominal mediotergite IX angulate, little extended distally (Fig. 10H View Figure 10 ); right paramere narrowly extended apically (Fig. 11B View Figure 11 ), with five setae on ventral margin and three on dorsal margin complementing two apical setae; left paramere narrow basally, evenly narrowed to a whiplike apex; aedeagal median lobe robust, broad dorsoventrally, apex distinctly curved ventrad to a narrowly rounded tip, its apical face slightly flattened; aedeagal median lobe internal sac with flagellum, flagellar sheath, and dorsal plate, flagellum and flagellar sheath curved ventrad apically (Fig. 10F-G View Figure 10 ), a patch of stout macrospicules present just inside ostial opening apicad flagellar structures. The median lobe apex is extended more in the specimen from Mt. Panié (Fig. 10F View Figure 10 ) than in the Mandjélia male (Fig. 10G View Figure 10 ). A third male from Mandjélia summit, 750-780 m elevation (MNHW) exhibits a lobe apex of intermediate extension. This continuous variation coupled with the extreme similarity of internal sac structures argues for conspecificity of these populations.

Female reproductive tract (n = 1). Bursa copulatrix elongate, length more than twice circumference, surface translucent, wrinkled, membranous (Fig. 12C 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; an elongate laminar 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 two to three setae laterally on apical margin, middle seta of series largest, several small setae scattered along medial margin (Fig. 13C View Figure 13 ); gonocoxite 2 moderately narrow basally, medial length more than twice basal width; two broad lateral ensiform setae present, apical seta larger.

Types - Holotype male (MNHN): NEW CALEDONIA / Mt. Panié / 16 May 1984 / G. monteith & D. Cook // Q.M. BERLESATE No. 650 / 20.35S X 164.47E / Rainforest, 900 m / Litter // QUEENSLAND / MUSEUM LOAN / DATE: Nov. 2003 / No. LEN-1686 (green label) // genitalia in polyethylene vial with glycerine // HOLOTYPE / Mecyclothorax / Mecyclothorax laterorectus / J.K.Liebherr 2017 (black-bordered red label).

Paratypes (21 specimens). NEW CALEDONIA: Hienghène [vicinity, code PA 63], 150 m el., 20°41'S 164°57'E, 02-ix-1970, Franz (NHMW, 4); Mandjélia, 700 m el., 20°24'S 164°32'E, 12-v-1984, rainforest, Q.M. berlesate 648, sieved litter, Monteith & Cook (QMB, 2), montane rainforest, 700-780 m el., 20°24'S 164°32'E, Pandanus , 20-xi-2008, Wanat (MNHW, 1), 750-780 m el., 20°24'S 164°32'E, 01-xi-2007, sieved litter, Wanat (MNHW, 5), summit, 750 m el., 20°24'S 164°32'E, hand collecting, 06-07-xi-2001, lot 8750, Burwell & /Monteith (QMB, 1), rainforest, sieved litter, 06-07-xi-2001, lot 1055, Monteith (QMB, 3), flight intercept trap, 29-xi-2003-11-i-2004, lot 11486, Monteith (QMB, 1), 780 m el., 20°24'S 164°32'E, berlesate, sieved litter, 12-xii-2004, lot 11941, Monteith (QMB, 2); Mt. Panié, rainforest, 900 m el., 20°33'S 164°45'E, Q.M. berlesate 650, litter, 16-v-1984, Monteith & Cook (QMB, 1); Roche d’Ouaïème, near Hienghène [PA 65], 500-700 m el., 20°37'S 164°52'E, 03-ix-1970, Franz (NHMW, 1).

Etymology.

As in the preceding two species (Fig. 9A-C View Figure 9 ), the broad pronotal base leads to the use of latero- to modify the adjectival Mecyclothorax rectus , which denotes the right pronotal hind angles of these beetles.

Distribution and habitat.

This species is distributed in the northern reaches of the Chaîne Centrale, from Mandjélia south to near Hienghène (Fig. 14 View Figure 14 ). Elevations range 700-900 m for credible collecting localities where complete information was provided on the specimen label. Of the 22 specimens known, 14 were recovered from sieved litter. Other collecting situations include hand collecting (1, QMB), flight intercept trap (1, QMB), and association with Pandanus ( Pandanaceae ) screw palm (1, MNHW).