Mecyclothorax lophoides (Chaudoir)

Liebherr, James K., 2018, Taxonomic review of Australian Mecyclothorax Sharp (Coleoptera, Carabidae, Moriomorphini) with special emphasis on the M. lophoides (Chaudoir) species complex, Deutsche Entomologische Zeitschrift 65 (2), pp. 177-224 : 177

Mecyclothorax lophoides (Chaudoir) Figures 2F, 4 C–D, 9F, 10F, 11C, 12B, 13B, 14 A–C

Anchomenus lophoides Chaudoir, 1854: 135.

Platynus lophoides Gemminger & Harold, 1868: 373.

Cyclothorax lophoides Blackburn, 1892: 481.

Agonum lophoides Csiki, 1931: 848.

Mecyclothorax lophoides Moore, 1984: 164.

Cyclothorax punctipennis Blackburn, 1889: 1388 (misidentification?, Blackburn 1892: 481).

Diagnosis

(n = 5). This species is characterized by a narrow, moderately cordate pronotum, the lateral margins slightly sinuate anterad obtuse, moderately projected hind angles (Fig. 2F); MEW/BPW = 1.57-1.68, MPW/PL = 1.18-1.22. The pronotal lateral marginal depression is very narrow, with only the narrowest indication of microsculpture between the convex disc and the marginal bead. The hind angle is obtuse, rounded at its apex, with the basal pronotal seta set slightly anterad the angle. The marginal depression continues for only a short distance mesad the hind angle. The median base is covered with ~10 erratically distributed small punctures each side of midline. The laterobasal depression is a longitudinal depression lined with 4-5 larger punctures, with the flat area between depression and the marginal bead also bearing several larger punctures. The prosternum is medially depressed from the prosternal process between the procoxae 1/2 the distance toward the anterior margin, the depression lined with 6-7 pits. The anteapical groove is shallowly punctate laterally, continuous and irregularly indented medially, and the marginal bead of the procoxal cavity is bordered anteriorly by about 3 very shallow punctures. The mesepisternum is punctate at its deepest portion, about 9 deep punctures in 2-3 dorsoventral rows. The elytra are narrowly subparallel (Fig. 4 C–D), with the humeral angles distinctly obtuse; MEW/EL = 0.64-0.69. The parascutellar striole is composed of 4-6 small, deep, isolated punctures. Elytral striae 1-6 are present on the disc, though striae 2-6 are absent basally and from the apical quarter to half, the outer striae progressively shorter. The strial punctures are isolated, progressively so apically, and the sutural stria is smooth or only slightly punctate in the apical half (Fig. 12B). Body coloration varies from dark brunneous (Fig. 4C) to piceous (Fig. 4D), with the legs correspondingly brunneous to piceous; i.e. there is less contrast between leg and body color than in M. peryphoides (Fig. 5B) or M. cordicollis (Fig. 5C). The elytral apex may be slightly paler than the disc in the brunneous specimens, however any difference is gradual, not a distinct transition as in M. cordicollis (Fig. 5C). Elytral margins are concolorous with the disc in the darker specimens. Cuticular microsculpture is relatively less developed in this species than in M. darlingtoni , M. jameswalkeri , M. peryphoides , or M. cordicollis , with: 1, frons glossy, indistinct transverse lines visible over portions of the surface; 2, pronotal disc glossy with shallow elongate transverse microsculpture visible outside the area of reflection; 3, flat elytral intervals covered with dense transverse lines producing an iridescent reflection. Standardized body length 3.8-4.9 mm. Setal formula ++/++/+2++.

Male genitalia (n = 12). Aedeagal median lobe dorsoventrally broad, the apex broadly rounded and slightly projected beyond the apical margin of ostium (Fig. 14A, C); flagellum elongate and hooklike, the flagellar sheath of similar length, its surface scabrous (Fig. 14 A–B), dorsal plate ovoid, lightly sclerotized (Fig. 14B); right paramere expanded basally, narrowed beyond midlength, the ventral surface with ~9 setae along margin, dorsal margin with 4 setae in apical half (Fig. 13B); left paramere narrow basally, evenly narrowed to apex.

Female reproductive tract (n = 2). Bursa copulatrix squat, as broad as long (Fig. 9F); helminthoid sclerite broad basally, with distinct mediodistal projection; spermathecal duct straight, narrow, evenly sclerotized, as long as spermathecal reservoir; basal gonocoxite with 4-5 apical setae plus a large seta at the apicomedial angle (Fig. 10F); apical gonocoxite subtriangular, broadly rounded apically; lateral ensiform setae small, narrow; apical nematiform setae in apical sensory furrow.

Type information.

Lectotype male (MNHN) hereby designated: pointed specimen // Musaeo Chaudoir [red typeface] // Lectotype [red label] // Museum Paris / ex. Coll. Oberthur // Mecyclothorax (Ch.) det. P. M. Johns. There are also a male paralectotype and a female paralectotype (MNHN).

Distribution and habitat.

M. lophoides is allopatrically distributed to the south of its adelphotaxon M. darlingtoni , with localities ranging from northeastern New South Wales southward through eastern N.S.W. to Melbourne (Fig. 11C). Non-type material and repositories include: A.C.T.: Paddy’s R. 1 mi. S Cotter Dam (ANIC, 1); Smoker’s Gap 43 km SW Canberra (CAS, 10; CUIC, 2): NSW: Blackheath (MVM, 1); Braidwood (CUIC, 2; MCZ, 37); Mt. Kosciuszko (MCZ, 2); New England N. P., Thungutti Camp (ANIC, 3): VIC: Dandenong Ck. (MVM, 1); Gellibrand R., Otway Ranges (MCZ, 1); Oakleigh (MVM, 1); Portland to Pt. Fairy (CUIC, 1; MCZ, 21); Wilson’s Promontory (ANIC, 1); Winchester (MCZ, 1).

Specimens of this species collected by John Nunn on King Island ( Moore 1984: 164) were preceded temporally by beetles laid down from 143,000-75,000 years ago in subfossiliferous deposits at Yarra Creek, King Island, during the Pleistocene last interglacial ( Porch et al. 2009). Long-term residence on King Island suggests the species can persist in communities ranging from the present more mesic, more seasonal forest types to the wetter, more aseasonal forests present on King Island during the Pleistocene. All specimens are vestigially winged.