Mecyclothorax jeanneli 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 : 23

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/834CBF6A-2041-4A93-B068-5CDE22913FB5
taxon LSID	lsid:zoobank.org:act:834CBF6A-2041-4A93-B068-5CDE22913FB5
treatment provided by	Deutsche Entomologische Zeitschrift by Pensoft
scientific name	Mecyclothorax jeanneli Liebherr
status	sp. n.

Treatment

5. Mecyclothorax jeanneli Liebherr sp. n. Figures 9E View Figure 9 , 10N-R View Figure 10 , 11D View Figure 11 , 12E View Figure 12 , 13E View Figure 13 , 15 View Figure 15

Diagnosis.

The diagnosis for M. fleutiauxi serves to summarize external diagnostic characters for this species (Fig. 9D-E View Figure 9 ). Internally, the male aedeagal median lobe has a much shorter apex in beetles of this species, with the tip extended beyond the apical ostial margin only as much as the width of the median lobe at that point (Fig. 10N-R View Figure 10 ). The female reproductive tract differs in that the dorsal lobe of the bursa copulatrix is as long as the ventral or principal lobe (Fig. 12E View Figure 12 ), with the spermathecal duct again entering at its apex. Standardized body length 4.4-5.3 mm. Chaetotaxy -/+//+/-//+/1-2/+/+.

Description

(n = 10). Head capsule narrowly elongate, with large, moderately convex eyes, ocular lobe meeting gena at obtuse angle, a broad shallow groove indicating juncture; 20 ommatidia along horizontal diameter of eye; ocular ratio 1.42-1.51, EyL/EyD = 2.8-3.4; frontal grooves sinuously canaliculate, deepest posterad frontoclypeal suture at a line between posterior margin of antennal fossae, briefly prolonged onto clypeus (as in Fig. 1B View Figure 1 ); mandibles elongate, mandibular ratio 1.9; ligular anterior margin angularly rounded to ligular seta, concave between setae, the two setae separated by two setal diameters (as in Fig. 1I View Figure 1 ); paraglossae thin, extended as far beyond ligular margin as half of basal length to margin; antennae moderately elongate, antennomere 9 length 2.05 × maximal breadth; antennomere 3 glabrous except for apical ring of setae. Pronotum vase-shaped, lateral margins meeting base in a smooth convex curve, hind angles nonexistent (Fig. 9E View Figure 9 ); MPW/PL = 1.23-1.30; front angles protruded, obtusely rounded; basal margin bordered by broadly convex marginal bead that joins fine lateral marginal beads at very small, shallow laterobasal depressions; median longitudinal impression fine and shallow on disc, terminated anteriorly at a small depression at position of anterior transverse impression; anterior transverse impression broad, very shallow, traceable to front angles; proepisternum separated from prosternum by a broad shallow groove both anteriorly and ventrally; prosternum with shallow anteapical impression laterally, impression absent from ventral 2/3 of circumference; prosternal process broadly depressed between procoxae, that depression extended anteriorly where it broadens to a depressed anterior face extended nearly to prothoracic anterior margin. Elytra elongate, ovoid, humeri quickly sloping posterad outside humeral angles; MEW/EL = 0.70-0.75; basal groove very briefly recurved laterad scutellum, humeral angle tightly rounded; all striae broad and shallow on disc, intervening intervals only slightly convex; one to two dorsal elytral setae present in third interval, if one, the posterior seta is absent (in 3 of 10 specimens scored); shallow remnants of the sutural stria plus striae 2 and 7 traceable at apex; elytra appressed and conjoined apically, sutural intervals narrower and distinctly upraised at apex. Pterothoracic mesepisternal anterior surface smooth; mesosternal-mesepisternal suture incomplete, obsolete to absent anteriorly (as in Fig. 3B View Figure 3 ); metepisternum very foreshortened, maximum width/lateral length = 1.3; metepisternal-metepimeral suture complete. Abdomen with broad crescent-shaped depression along suture between first and second ventrite, second ventrite broadly depressed behind 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 distinct, a mix of isodiametric and transverse sculpticells; pronotal disc and base covered with elongate transverse mesh, sculpticells on disc 3-4 × broad as long, those on base somewhat less broad, surface iridescent; elytra iridescent, disc covered with transverse-line microsculpture, apex with transverse lines loosely joined into a transverse mesh.

Male genitalia (n = 23). Antecostal margin of abdominal mediotergite IX robust distally, broadly angulate and obliquely truncate (Fig. 10O View Figure 10 ); right paramere very elongate, apical half narrowed to a whiplike extension (Fig. 11D View Figure 11 ), five setae along ventral margin well separated from apical pair of setae, dorsal surface glabrous; left paramere broadly quadrate basally, distinctly narrowed to a whiplike extension; aedeagal median lobe moderately gracile, apical half evenly narrowed to tip that protrudes less than its dorsoventral dimension beyond the apex of the ostial opening (Fig. 10N-R View Figure 10 ); aedeagal internal sac bilobed, the dorsal lobe subequal to the apical lobe (Fig. 10Q View Figure 10 ), a small crescent-shaped structure with lightly sclerotized outer margin-interpreted as a reduced flagellar sheath-dorsad gonopore on apical lobe. There is less variation among males with regard to extension of the median lobe apex (Fig. 15 View Figure 15 ) - understandable due to the generally shorter extension-and this variation is not geographically associated. Thus the species geographic limits include all populations lying south and east of Mt. Humboldt (Fig. 15 View Figure 15 ).

Female reproductive tract (n = 8). Bursa copulatrix bilobate, a broad ventral lobe complemented by narrower dorsal lobe of subequal length, dorsal lobe bearing spermathecal duct at apex (Fig. 12E View Figure 12 ); bursal walls moderately thick, wrinkled, semitranslucent; spermathecal duct that enters apex of bursal dorsal lobe slightly broader than spermathecal reservoir, and about twice length of reservoir, spermathecal gland duct entering onto apex of spermathecal reservoir; well-developed ligular apophysis present on common oviduct as far distant from base of common oviduct as apex of ventral bursal lobe; basal gonocoxite 1 with apical fringe of two setae, a few microsetae near apicomedial margin of gonocoxite complementing very few medial setae (Fig. 13E View Figure 13 ); apical gonocoxite 2 falciform with an elongate laterobasal extension, basal width more than 0.75 × length; lateral ensiform setae elongate and broad.

Types - Holotype male (MNHN): NEW CALEDONIA.9944 / 22°11 ’Sx166°01’ [sic, crossed out and hand corrected to 31'E] / Mt Koghi, 750m / 29Nov2000.GB Monteith / Pyrethrum, trunks&logs // QUEENSLAND / MUSEUM LOAN / DATE: Nov. 2003 / No. LEN-1686 (green label) // HOLOTYPE / Mecyclothorax / Mecyclothorax jeanneli / J.K.Liebherr 2017 (black-bordered red label). The type locality longitude is incorrect on the label, and is corrected ( Google Earth Pro 2017).

Paratypes (156 specimens; EMEC, HNHM, MNHW, NHMW, QMB): see Suppl. material 2.

Etymology.

This species epithet is a patronym honoring Dr. René Jeannel, whose extensive body of literature dominates 20th Century carabidology. Dr. Jeannel’s early and perspicacious appreciation of Wegenerian historical biogeography was ground breaking in Entomology ( Jeannel 1942), and we have yet to test fully the biogeographic hypotheses he proposed in his many contributions. More close to home, the necessity of examining the male genitalia to determine M. jeanneli versus its sister species, M. fleutiauxi , reiterates Dr. Jeannel’s pioneering research on the underlying homologies of insect genitalia ( Jeannel 1955) and his extensive use of insect genitalia to diagnose species (e.g. Jeannel 1944).

Distribution and habitat.

This species is distributed in the southern end of Grand Terre, from Mt. Humboldt on the north to Forêt Nord on the south (Fig. 15 View Figure 15 ), allopatric to the northerly range of its adelphotaxon, M. fleutiauxi . These beetles are known from any even greater altitudinal range than M. jeanneli , with recorded elevations ranging 160-1600 m. As with M. jeanneli , the vast majority (150 of 156 specimens) have been collected on tree trunks or downed logs, most via application of pyrethrin spray. A series of 31specimens was taken during one collecting event through spray application onto a moss-covered trunk (QMB). Thus, like M. jeanneli , this species is associated with emergent plant substrates, not the ground-level litter microhabitat.