Mecyclothorax laterovatulus 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 : 30-32

9. Mecyclothorax laterovatulus Liebherr sp. n. Figures 16D , 17G-H , 18D , 19

Diagnosis.

This and the following species M. najtae (Fig. 16D-E ) are characterized by very obtuse pronotal hind angles that are rounded apically, pronotal lateral margins straight to only indistinctly concave before the very obtuse angles. The elytra are broader basally in beetles of this species, with the humeri extended anterad and the basal groove narrowly rounded near the base of stria 6, and elytral length is relatively longer than in M. najtae , with MEW/EL = 0.85. The outer elytral striae 5-7 are well impressed at midlength in this species, versus obsolete to entire absent laterally in M. najtae . The configuration of the male aedeagal internal sac-with elongate, curved flagellum and flagellar sheath and a dorsal plate (Fig. 17G ) - indicates this species’ true relatives (Fig. 7 ); M. laterorectus (Fig. 10F ) and M. laterosinuatus (Fig. 10C-D ). Chaetotaxy +/+//+/-//+/2/+/+.

Standardized body length 4.1 mm.

Description

(n = 1). Head capsule broad, foreshortened, eyes small, moderately convex, ocular lobe meeting gena at very obtuse angle; 15-16 ommatidia along horizontal diameter of eye; ocular ratio 1.39, ocular lobe ratio 0.89, EyL/EyD = 3.13; 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 1.8; 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 elongate, antennomere 9 length 2.5 × maximal breadth; antennomere 3 glabrous except for apical ring of setae. Pronotum vase-shaped, hind angles broadly subangulate, lateral margins only slightly concave anterad angles (Fig. 16D ); MPW/ BPW = 1.66, MPW/PL = 1.24; front angles only slightly protruded, broadly obtuse, APW/BPW = 0.93; median base coplanar relative to disc, unmargined; laterobasal depression with longitudinal tubercle inside hind angle, defined medially by longitudinal border with median base; median longitudinal impression fine and shallow on disc, posteriorly terminated at deep lenticular pit anterad median base, terminated anteriorly at very broad and shallow anterior transverse impression; proepisternum separated anteriorly from prosternum by fine shallow groove, distinctly separated ventrally by smooth, deep groove; prosternal process deeply, narrowly depressed between procoxae, that depression extended 1/4 distance toward anterior prothoracic margin. Elytra broadly ellipsoid to hemiovoid, humeri extended laterally, humeral angle rounded outside pronotal hind angles; MEW/EL = 0.85; basal groove extended anterad from scutellum to humerus, with depressions at bases of sutural and elytral striae 4-5; sutural stria deep throughout length, striae 2 and 5-7 almost as well developed, striae 3-4 shallower though still evident; striae 1-2 and 7 evident apically, elytra appressed and conjoined apically, sutural intervals narrower and upraised at apex. Pterothoracic mesepisternal anterior furrow with five pitlike depressions in one vertical row; metepisternum maximum width/lateral length = 0.88; mesosternal-mesepisternal suture complete (as in Fig. 3A ); metepisternal-metepimeral suture incomplete, shallower and incomplete laterally. Abdomen with deep crescent-shaped depression along suture between first and second ventrite, 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 and vertex an evident transversely stretched isodiametric mesh; pronotal disc and base covered with elongate transverse mesh, sculpticell breadth 3-4 × length, surface iridescent, sculpticells in laterobasal depressions less transverse, breadth 2-3 × length; elytra iridescent, disc with dense transverse lines loosely connected into a mesh, apex covered with transverse lines. Femora rufobrunneous, a piceous cloud in basal 2/3.

Male genitalia (n = 1). Antecostal margin of abdominal mediotergite IX angulate, not extended (Fig. 17H ); right paramere narrow, narrowly extended apically (Fig. 18D ), with two setae on the ventral margin complementing a single apical seta; left paramere narrow basally, extended as an elongate, whiplike extension with a single apical seta; aedeagal median lobe robust, broad dorsoventrally, apex evenly narrowed dorsally and ventrally to a narrowed rounded tip (Fig. 17G ); aedeagal median lobe internal sac with dorsal plate, dorsally curved flagellum and flagellar sheath.

Type - Holotype male (MNHN): NEW CALEDONIA 11665 / 21°11'S 165°16'E. / Aoupinie, summit. 1000 m / 2Oct2004. G.Monteith / pyrethrum, trees&logs // QUEENSLAND / MUSEUM LOAN / DATE: July 2005 / No. LE 05.24 // New Caledonia Mecyclothorax revision / measured specimen 1 / J.K. Liebherr 2016 ♂1 // genitalia in polyethylene vial with glycerine // HOLOTYPE / Mecyclothorax / Mecyclothorax laterovatulus / J.K.Liebherr 2017 (black-bordered red label) /

Etymology.

Though this species is separated in the dichotomous key and therefore in the species treatment sequence from its broad-bodied phylogenetic relatives (Fig. 9AC), this species is given the compound adjectival epithet Mecyclothorax laterovatulus to signify the broad body and ovoid pronotum coupled with rounded pronotal hind angles (Fig. 16D ), thereby making the species name reiterate the names of those other species; M. laterobustus , M. laterorectus , and M. laterosinuatus .

Distribution and habitat.

The lone holotype of this species was collected on Aoupinié summit at 1000 m elevation via application of pyrethrin spray to trees and logs (Fig. 19 ). Based on restriction of its adelphotaxon, M. laterorectus + M. laterosinuatus , as well as the closely related M. laterorobustus (Fig. 7 ) to ground-level microhabitats, it is predicted that additional specimens of this species will be collected predominantly in ground level litter, or from mossy subcortical microhabitats.

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 7. Strict consensus cladogram of 16 equally most-parsimonious trees derived from cladistic analysis of 65 moriomorphine taxa, including the secondary outgroup Neonomius laevicollis, six primary outgroup taxa in Amblytelus and allied genera, and 58 ingroup terminals; 57 Mecyclothorax species plus two genitalic forms of M. andersoni. Species terminals are labeled with species name and three-letter abbreviation of relevant generic or subgeneric name. Full listing of included taxa along with subgeneric assignments is presented in Table 2. Cladistic analysis is based on 137 characters (see character descriptions for nature of each character Areas occupied by the included taxa indicated by abbreviations following species epithets: Bo, Borneo; EOZ, eastern Australia, i. e. east of the Nullarbor Plain; FP, French Polynesia, Tahiti; HI, Hawaiian Islands, Maui; Jv, Java; LH, Lord Howe Island; NC, New Caledonia; Nf, Norfolk Island; NNZ, North Island of New Zealand; NZ, generally distributed across New Zealand; OZ, generally distributed across Australia; PNG, Papua New Guinea; QOZ, restricted to Queensland, Australia; SNZ, South Island of New Zealand plus Chatham Islands; SP & A, St. Paul and Amsterdam Islands; WOZ, western Australia, i. e. west of the Nullarbor Plain.

Figure 10. Male aedeagal median lobe and parameres, and ring sclerite-mediotergite plus antecostal margin, tergite IX-of Mecyclothorax (Phacothorax) spp.: A-B, M. laterorobustus, right view, dorsal view in situ (Ningua); C, M. laterosinuatus, right view (Col d'Amieu); D, M. laterosinuatus, right view (Touho TV tower); E, M. laterosinuatus ring, dorsal view; F, M. laterorectus, right view (Mt. Panie); G-H, M. laterorectus, right vew, dorsal view in situ (Mandjelia); I-J, M. fleutiauxi, right view, dorsal view in situ (Mt. Do); K-L, M. fleutiauxi, right view, sac inverted and everted (Me Maoya); M, M. fleutiauxi, right view (Ningua); N-O, M. jeanneli, right view, dorsal view in situ (Mt. Humboldt, 1350 m); P, M. jeanneli, right view (Mt. Humboldt, 1300 m); Q, M. jeanneli, right view, sac everted (Mt. Dzumac); R, M. jeanneli, right view (Riviere Bleue). See Table 2 for abbreviations.

Figure 16. New Caledonian Mecyclothorax (Phacothorax) spp., dorsal view: A, M. plurisetosus; B, M. megalovatulus; C, M. octavius; D, M. laterovatulus; E, M. najtae.

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 19. Geographical distributions of Mecyclothorax (Phacothorax) spp.