Qecyclothorax (Meonochilus) lewisensis subsp. subgenus, Meonochilus Liebherr & Marris, 2009 [new status]

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 : 12

subgenus Meonochilus Liebherr & Marris, 2009 [new status]

Diagnosis.

Species of this subgenus share a robust, convex body shape with Qecyclothorax spp. (Fig. 8B-C ), though in all Meonochilus spp. the elytral striae are well developed and punctate, with striae 1-7 deep at elytral midlength. The pronotal median base is depressed relative to the convex disc ( Liebherr 2011, figs 9-10). The broad elytra are associated with a rounded humerus, a condition also observed among some New Caledonian Phacothorax and various species of subgenus Mecyclothorax Mecyclothorax . The head is transversely depressed behind the eyes, and the mentum is broad: over 3 × broad as long. Opposed to New Zealand species of subgenus Mecyclothorax Mecyclothorax (as in Hawaii’s M. montivagus , Fig. 1G ), the ligula is rounded apically with the ligular setal sockets separated by only 2 diameters. The paraglossae extend beyond the ligular margin 1-2 × the distance from their base to the ligula’s margin (Fig. 1F ). The male parameres also differ from those occurring among taxa of other Mecyclothorax subgenera, with the right paramere club-shaped and broadly setose apically (Fig. 5C ), and the left paramere broadly conchoid.

Member species.

The six species of this subgenus were revised by Liebherr (2011), and comprise the five species in this analysis (Fig. 7 ) plus M. placens (Broun). All species are restricted to North Island, New Zealand.

New taxonomic status.

Liebherr and Marris (2009) proposed this clade as a distinct genus based on the great disparity between Meonochilus spp. and other New Zealand species currently assigned to subgenus Mecyclothorax Mecyclothorax . A subsequent cladistic analysis ( Liebherr 2011) with taxon representation inadequate to display the phylogenetic structure within Mecyclothorax affirmed that generic status. The current analysis including a much more comprehensive sampling of Mecyclothorax spp. requires revision of that decision, with Meonochilus now treated as a subsidiary monophyletic subgenus of Mecyclothorax (Fig. 7 ). The member species include: 1, Mecyclothorax (Meonochilus) amplipennis (Broun) comb. n.; 2, Mecyclothorax (Meonochilus) bellorum (Liebherr) comb. n.; 3, Mecyclothorax (Meonochilus) eplicatus (Broun) comb. n. ; 4, Mecyclothorax (Meonochilus) placens (Broun) comb. n.; 5, Mecyclothorax (Meonochilus) rectus (Liebherr) comb. n.; 6, Mecyclothorax (Meonochilus) spiculatus (Liebherr) comb. n.

Figures

Figure 1. Head and mouthpart structures of Mecyclothorax spp. A-C. Head capsule, dorsal view: A, M. goweri; B, M. fleutiauxi; C, M. laterorectus. D-I, Mentum, labial palps and ligula: D, M. peryphoides, ventral view; E, M. storeyi, ventral view; F, M. amplipennis, dorsal view; G, M. montivagus, dorsal view; H, M. kanak, ventral view; I, M. fleutiauxi, ventral view. Abbreviations include: aso, anterior supraorbital seta; pso, posterior supraorbital seta.

Figure 5. Paired left (above) and right (below) parameres of Mecyclothorax spp. (ectal view): A, M. blackburni; B, M. storeyi; C, M. amplipennis; D, M. montivagus; E, M. laterobustus. As the aedeagal assembly of M. storeyi males is inverted relative to other Mecyclothorax species (Moore 1984), the configuration of the upper, or right paramere of M. storeyi should be compared to the ventral, or left parameres of the other species, and vice versa.

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 8. Mecyclothorax spp., dorsal view, with subgeneric assignments: A, M. (Eucyclothorax, subgen. n.) Mecyclothorax blackburni (type species); B, M. (Qecyclothorax, subgen. n.) Mecyclothorax storeyi (type species); C, M. (Meonochilus, status n.) Meonochilus amplipennis (type species); D, M. (Mecyclothorax) montivagus (type species); E, M. (Mecyclothorax) lissus.