Mecyclothorax blackburni (Sloane)

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 blackburni (Sloane) Figures 2D, 3D, 7E, 8D, 9D, 10D, 11B

Cyclothorax blackburni Sloane, 1898: 472.

Mecyclothorax blackburni Csiki, 1929: 487 (see Nomenclatural note).

Diagnosis

(n = 5). Beetles of this species are very narrow-bodied, with a narrow, cordate pronotum (Fig, 2D), and narrow, subparallel elytra and an elongate head (Fig. 3D). The pronotal median base is coplanar with the disc, but distinguished by the presence of about 14 large deep punctures each side. The right pronotal hind angles protrude both laterally and posteriorly in association with a broadened marginal bead at the articulatory socket of the basal pronotal seta. Otherwise the pronotal lateral margin is extremely narrow, defined only by a marginal bead. Basally the elytral striae consist of series of closely spaced punctures, their separations equal to their diameters. Puncture size decreases, and puncture distances increase laterally and apically on the elytra, with stria 7 represented by only a few small punctures at mid-length. Interval 8 is broadly convex apically, and the elytral plica is well developed and evident in dorsal view. Ventrally, the body punctation includes a punctate median depression anterad the prosternal process, punctures along the lateral reaches of the prosternum, and a punctate anteapical groove ( Liebherr 2018, fig. 2E). The lateral reaches of the mesosternum, metasternum, and all of the metepisternum are also intensely punctate. The basal 3 abdominal ventrites are covered with numerous small punctures laterally, and the suture between visible ventrites 2 and 3 is traceable only as a shallow groove. The apical margin of the male apical abdominal ventrite bears the usual 2 setae, 1 each side, but also 4 small medial setae in the position observed in Mecyclothorax females. Standardized body length 4.2-4.9 mm. Setal formula ++/++/+2++.

Male genitalia (n = 2). Aedeagal median lobe very broad and only slightly curved, the apex with subacuminate ventroapical projection and a broadly convex dorsoapical expansion resulting in a broadly concave apical face (Fig. 7E); flagellum short, flagellar sheath robust, and dorsal plate lightly sclerotized, difficult to discern in single available uneverted male; right paramere narrow, with 4 small setae ventrally and dorsal surface glabrous (Fig. 8D); left paramere broad basally, narrowly attenuate apically.

Female reproductive tract (n = 1). Bursa copulatrix elongate, extended dorsodistally beyond juncture of common oviduct and bursa (Fig. 9D); helminthoid sclerite robust, with distal projection; spermathecal duct straight and slightly longer than spermathecal reservoir, evenly, moderately sclerotized; basal gonocoxite with 1 larger seta apically, a smaller seta present or not (Fig. 10C); apical gonocoxite narrowly triangular, narrowed apically to acuminate apex; lateral ensiform setae narrow, moderately elongate; apical nematiform setae in apical sensory furrow.

Type information.

Holotype male (SAMA): card mounted // TY Pinjarrah // Holotype M. blackburni / PJD Sl. [red label].

Nomenclatural note.

Sloane (1903) proposed the replacement of Cyclothorax MacLeay (1871) (not Frauenfeld 1868) with Sharpʼs Mecyclothorax (1903), mentioning the new combinations of M. lateralis (Castelnau), M. fortis (Blackburn) = M. minutus (Castelnau) [NEW SYNONYMY herein], M. punctatus (Sloane), and M. curtus (Sloane). By not mentioning M. blackburni , nor also M. eyrensis (Blackburn), M. peryphoides (Blackburn), M. cordicollis (Sloane), M. minutus (Castelnau), and M. punctipennis (MacLeay), Csiki (1929) became the first to propose these combinations (see also below).

Distribution and habitat.

M. blackburni is known only from coastal Western Australia (Fig. 11B) from Perth south to Harvey (ANIC, 2 specimens). The Perth locality is denoted as "Bridgelʼaʼ (MVM, 1 specimen), which is here interpreted to be an abbreviation of Bridgeleigh, a remnant area of bush vegetation in Swan Valley, Wanneroo. Commander J.J. Walker, Royal Navy, collected a specimen at Fremantle in 1914 (BMNH). When Sloane (1898) described the species based on one specimen received from Arthur Lea he listed no biological information, and none accompanies the other four available specimens. Those four specimens are all macropterous.