Mecyclothorax lewisensis estriatus, Liebherr, James K., 2018

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 lewisensis estriatus subsp. n. Figures 5D, 11E

Mecyclothorax lewisensis Moore, 1984: 165.

Mecyclothorax lewisensis uncinatus Baehr, 2003: 74.

Diagnosis

(n = 1). This taxon is distinguished from all others of subgenus Qecyclothorax by the reduced elytral striation, with only the sutural stria evident, and the positions of all outer striae only traceable by the longitudinal tracks of trachea ( Shelford 1915). As for all Qecyclothorax , the elytra exhibit only a single dorsal elytral seta positioned near midlength (Fig. 5D). Consistent with membership in M. lewisensis , this beetle exhibits a quadrisetose clypeus and a pronotum with explanate lateral margins that are indistinctly sinuate basally. The parascutellar seta are very short and fine, and they are set in shallow depressions, however careful examination allows their discernment along with the fine articulatory sockets from which they extend. Baehr used the comparative breadth of the pronotal base relative to its apex as one criterion to differentiate the two subspecies M. lewisensis and M. l. uncinatus : the former with a ratio APW/BPW <0.83 (note inverted ratio herein versus Baehr 2003), the latter with APW/BPW> 0.85. In the single specimen of M. l. estriatus , APW/BPW = 0.85. Standardized body length for the type specimen below, 3.3 mm. Setal formula ++/++/+1++.

Description.

Head broad, frontal groove deep, arcuately convergent toward clypeus, continued onto clypeus, terminated posteriorly midway between 2 supraorbital setae; eyes moderately convex, MHW/mFW = 1.52, covering much of ocular lobe, EyL/OLL = 0.83; antennae elongate, long enough so that apex would extend to basal 1/4 of elytra, antennomere 9 length/maximal breadth = 1.89; mentum tooth with sides acute, apex broadly rounded; ligular apex narrowed, slightly concave between ligular setae, setae separated by 2 setal diameters; paraglossae extended as far beyond ligular apical margin as distance from base to ligular margin. Pronotum transverse, MPW/PL = 1.41, moderately constricted basally, MPW/BPW = 1.35; lateral pronotal seta placed 1 diameter mesad lateral margin depression, depression very narrow at front, gradually widened to explanate at hind angle; basal margin nearly straight, slightly convex between laterobasal depressions, margin flat and effaced behind laterobasal depressions, a convex roll medially; median base depressed relative to disc, smooth with ~3 small punctures each side mesad laterobasal depression; laterobasal depression a linear to slightly outwardly arcuate line of 3-4 broad punctures, the area laterad line of punctures broadly convex to explanate lateral margin; median longitudinal impression fine, deep, adjacent depression covered with transverse wrinkles on disc; anterior transverse impression broad, evenly depressed fore and aft, the anterior callosity broadly, slightly convex to front margin; front angles slightly protruded, subangulate with marginal bead mesad angle that is continuous with transverse impression; prosternum depressed medially anterad procoxal cavities, the depressionʼs surface irregular with 3 shallow irregularities disturbing the surface; anteapical groove very shallow laterally discontinuous, not present medially; lateral reaches of prosternum irregular, procoxal cavity with very fine marginal bead. Mesepisternum covered with 7 large, isolated pits on a smooth surface, the pits arranged in 2 dorsoventral rows; metepisternum nearly quadrate, lateral margin length 1.2 × maximal width. Elytral broadly hemiovoid (Fig. 5D), convex laterally with sides nearly vertical, disc flattened; basal groove slightly curved laterad position of parascutellar striole, punctate near basal positions of striae 3 and 4 (indicated by tracheae; Shelford 1915), and straight laterally to obtusely angulate humeri; elytral striae obsolete, striae 1 and 2 traceable only by very small serial punctures on disc, stria 3 less easily traced as punctures are irregular and easily confused with micropunctures scattered over cuticle; dorsal elytral setae short, in depressions that span only 1/4-1/2 of third interval; only stria 7 evident on elytral apex as a broad shallow depression connecting the subapical and apical elytral setae; stria 8 deep, present from posterad anterior series of lateral elytral setae, slightly irregular along length behind anterior series of lateral elytral setae; lateral elytral setae arranged as 7 + 6-7 setae; subapical sinuation very broad and shallow, the elytral plica visible in dorsal view. Head capsule with reduced microsculpture, frons glossy and vertex covered with fine transverse lines; pronotal disc glossy, a transverse mesh present over parts, sculpticell breadth 2 –3× length; pronotal base glossy, indistinct transverse mesh in laterobasal depression; elytral disc glossy, indistinct transverse lines outside area of reflection, apex glossy with indistinct transverse mesh in irregularly depressed areas. Coloration of head rufous on frons, darker on vertex; antennomeres 1 rufoflavous, 2-11 brunneous; Pronotal disc dark rufous, lateral margins broadly paler, rufoflavous, base a translucent amber; elytral disc rufobrunneous overall, but with a darker transverse field posterad dorsal elytral seta that continues along suture to apex leaving 2 paler lateroapical fields; sutural interval concolorous with adjacent intervals; proepipleuron rufoflavous with darker explanate margin; proepisternum dark rufous with subiridescent reflection; elytral epipleuron broadly rufoflavous, metepisternum rufobrunneous; abdomen rufobrunneous, apical 2/3 of apical ventrite flavous; femora flavous, tibiae flavous with rufous cast.

Female reproductive tract (n = 1). The unique female holotype was not dissected. Nonetheless, the gonocoxae extend from the abdominal apex, allowing the following characters to be assessed: basal gonocoxite with medioapical margin glabrous; apical gonocoxite broad basally with 2 lateral ensiform setae; apical nematiform setae in subbasal sensory furrow. These characters conform to states previously scored for M. lewisensis ( Liebherr 2018) though they are not definitive.

Holotype female (QMB): QLD: 20°21'S, 148°43'E / Brandy Creek, 150 m / 20 Nov 1992 / Monteith, Thompson / & Janetzki, Pyrethrum // HOLOTYPE / Mecyclothorax / lewisensis / estriatus / J.K. Liebherr 2018 (black margined red label).

Distribution and habitat.

The lone specimen of this subspecific taxon is from near the Queensland coast south of Cannonvale (Fig. 11E), approximately 600 km south of the localities near Mossman from where the other subspecies of M. lewisensis have been described ( Baehr 2003, fig. 6).