Mecyclothorax brispex Liebherr, 2017

Liebherr, James K., 2017, Review of Mecyclothorax Sharp (Coleoptera: Carabidae: Moriomorphini) from Papua New Guinea, with Descriptions of Five New Species, The Coleopterists Bulletin 71 (4), pp. 679-703 : 691-694

6. Mecyclothorax brispex Liebherr , new species ( Figs. 5 , 26 , 30 , 32 )

Diagnosis. Like M. cuccodoroi , M. loebli , and M. andersoni , M. brispex individuals exhibit glabrous pronotal hind angles, two dorsal elytral setae in the third interval, and the apical elytral seta present, the subapical seta being absent. However, unlike those three species, the pronotal median base is completely smooth in beetles of M. brispex , and the pronotal basal margin is continuously beaded medially. The pronotal hind angles are protruded and slightly obtuse, and the pronotal lateral marginal depression is extremely narrow, the beaded margin abutting the convex disc for most of its length. The eyes are very small and little convex, ocular ratio = 1.36–1.42 (n = 2), with the ocular lobe meeting the gena at more than a 150° angle. There are 13 ommatidia present along the horizontal diameter of the eye. The elytra are subiridescent, and covered with very transverse microsculpture consisting of transverse sculpticells, breadth 3–4X length, and transverse lines only loosely connected into a mesh.

Description. Head: Broad; small, slightly protruding eyes emphasizing broad basal portion of head ( Fig. 5 ), ocular lobe ratio = 0.72; frontal grooves broad, convergent on frons from mesad anterior supraorbital seta to very shallow frontoclypeal suture, then divergent onto base of clypeus; posteromedial margins of eyes depressed relative to vertex, eyes bulging dorsally; antennomere 3 glabrous except for apical setal ring; antenna filiform, elongate, antennomere 9 length 2.5X maximal breadth; anterior labral margin slightly emarginate, nearly straight; mandibles moderately elongate, length from dorsal condyle to apex 1.8X distance from condyle to anterolateral margin of labrum; vertex flat behind eyes, not impressed; mentum tooth projected, sides subparallel, apex tightly rounded; ligular apex narrowly rounded, ligular setae separated by 2 setal diameters, paraglossae extended about twice as far beyond ligular margin as distance from their base to ligular margin. Pronotum: Elongate, cordate ( Fig. 5 ), MPW/BPW = 1.52–1. 54, MPW/PL = 1.16–1.21; lateral setal position on disc 2 setal diameters inside lateral marginal depression; hind angles projecting, slightly obtuse, clearly defined by continuous, raised marginal bead; median base little depressed relative to disc, smooth, basal margin with continuous marginal bead between hind angles; median longitudinal impression absent from median base, narrowly and finely incised on disc, a small pit at juncture with anterior transverse impression; anterior transverse impression very shallow medially, well-developed, narrow and deep in outer 3/4 of breadth each side; anterior callosity broadly and slightly convex, anterior margin convex, without bead; front angles only slightly protruding, narrowly rounded; lateral marginal depression very narrow throughout length, narrowly lined with microsculpture at depth, edge beaded; laterobasal depression a slight broadening of lateral depression inside hind angle, a longitudinal depression defining its mesal margin at median base; prosternum with deep, smooth anteapical furrow that extends from lateral reaches across ventral surface, and a deep, longitudinal median fossa extending from prosternal process nearly to anteapical furrow, prosternal process convex between positions of trochanters; proepimeron with anterior and posterior grooves smooth. Elytra: Narrowly subparallel, dorsally convex with sides nearly vertical at marginal depression, humeri narrowly rounded but elytral base extending laterally beyond pronotal hind angles, MEW/EL = 0.70; parascutellar seta present; scutellum narrow, width at transverse groove/median length = 1.14; parascutellar striole deep, smooth; elytral basal groove evenly curved to subangulate humerus; striae 1–4 present on disc, striae 2–4 with elongate punctures, stria 5 incomplete but traceable, striae 6–7 obsolete; sutural stria shallowly present on apex only, stria 7 obsolete but traceable near apical seta, striae 2–6 absent; sutural apex conjoined with sutural intervals narrowly raised each side of suture; stria 8 smooth and deeply impressed at midlength; lateral marginal depression moderately broad inside rounded humerus, narrower behind, margin upraised throughout length; subapical sinuation briefly indented, equally curved anteriorly and posteriorly; lateral elytral setae 7 + 6; subapical elytral seta absent, apical seta in association with apex of stria 2 present. Mesepisternum: With 5–6 large punctures in 1–2 rows; metepisternum maximum width/lateral length = 0.79; metasternal process acute, apex extended as a parallel-sided knob, knob and lateral margins broadly convex; metathoracic wings vestigial, apex not extended beyond posterior margin of metanotum. Abdomen: Ventrites 1 and 2 separated by slightly sinuous suture laterally, surface of ventrite 2 not depressed; suture between ventrites 2 and 3 shallow but traceable laterally; longitudinal wrinkles present laterally on ventrites 2–3, broad, shallow depressions present laterally on ventrites 3–6. Microsculpture: Reduced on head, frons glossy with indistinct transverse lines, vertex with shallow, transverse mesh, sculpticell breadth 2X length; pronotal disc, pronotal median base, and elytral disc covered with elongate transverse mesh, sculpticell breadth 3–4X length, elytral disc subiridescent; elytral apex with very fine transverse lines; metasternum with evident transverse mesh, sculpticell breadth 3–4X length; lateral portions of basal abdominal ventrites with swirling isodiametric and transverse sculpticells. Coloration: Head rufopiceous, clypeus, labrum, and mouthparts rufobrunneous, palps flavous; antennae rufobrunneous, antennomeres 4–11 with piceous cast; pronotal disc rufopiceous, lateral and basal margins concolorous, apex translucent, rufous; elytral disc rufopiceous, sutural interval concolorous, lateral marginal depression narrowly rufobrunneous; proepipleuron and proepisternum rufopiceous, subiridescent; elytral epipleuron rufobrunneous dorsally, rufopiceous ventrally, metepisternum rufous with piceous cast; abdomen dark rufous, apical half of ventrite 6 flavous; femora rufobrunneous, tibiae rufobrunneous with piceous cast.

Female Reproductive Tract. Bursa copulatrix with spermatheca entering at dorsoapical common oviduct-bursal juncture via sclerotized helminthoid sclerite ( Fig. 26 ); bursa copulatrix sac-shaped, approximately twice as long as broad (compressed under a microslide cover slip); spermathecal duct short and well sclerotized; spermathecal gland duct entering at base of globose spermathecal reservoir; basal gonocoxite 1 with 2–3 apical fringe setae ( Fig. 30 ) and only a few small medial setae along apicomedial margin; apical gonocoxite 2 subtriangular, base narrowly extended laterally, bearing 2 gracile, lateral ensiform setae, a similarly shaped dorsal ensiform seta and 2 apical nematiform setae, those setae located in fossa and situated 0.27X gonocoxite length from apex.

Holotype. Female with abdominal ventrites removed and glued to platen and reproductive tract in polyethylene genitalia vial on pin ( EMEC, for deposition in NMNHS): MT FUGILIL / campsite / 2980 m. Western / Prov. 29.ix.75 / P. BERON // British Speleological / Expedition to Papua / New Guinea 1975 // HOLOTYPE / Mecyclothorax / brispex / J.K. Liebherr 2017 [black-bordered red label]. This specimen was part of the Barry Moore personal collection of carabid beetles transferred to the EMEC. As with the holotype of M. medioconstrictus , this specimen should be credited to the NMNHS. It was returned to the EMEC for accessioning and will be forwarded to the NMNHS for permanent deposition.

Paratype. Male with the same data as the holotype has the abdominal ventrites removed and glued to platen, but the genitalia are disassociated from specimen and presumably lost ( EMEC, for deposition in NMNHS). This specimen was found along with the holotype female in the Barry Moore personal carabid collection after the collection was transferred to the EMEC. Upon examination and attempted dissection, it was found that the specimen had already been dissected, with the genitalia no longer in association with the remainder of the body .

Etymology. The species epithet brispex commemorates the 1975 British Speleological Expedition to Papua New Guinea ( Brook 1976), during which the type specimens were collected. The species epithet, being an abbreviated concatenation of the expedition’ s name, should be treated as a random sequence of letters.

Distribution and Habitat. As for M. medioconstrictus , the types of M. brispex were collected in forested habitat on Mt. Fugilil ( Fig. 32 ), the elevation of the type locality recorded as 2,980 m. Since the summit elevation on the label of the M. medioconstrictus specimen is about 700 m higher than possible given current information ( Google Earth 2017), the type locality for this species at the “ 2980 m ” elevation campsite is likely to be lower than that by an indeterminate amount.

Figures

Figs. 5–8. Mecyclothorax species, dorsal habitus. 5) M. brispex; 6) M. gressitti; 7) M. sedlaceki; 8) M. amingwiwae. Range of standardized body lengths (in mm) and setal formulae (see text) for number of supraorbital setae each side, number of pronotal setae each side, number of dorsal elytral setae each elytron, and number of setae at the apex of each elytron are indicated.

Figs. 25–28. Mecyclothorax species, female gonocoxae, laterotergites VIII, and internal reproductive tract, ventral view. 25) M. andersoni; 26) M. brispex; 27) M. gressitti; 28) M. sedlaceki. Abbreviations are defined in Table 1; position of spermathecal duct dorsad bursa indicated by dashed lines; scale bars = 0.25 mm.

Figs. 29–31. Mecyclothorax species, female gonocoxae, right side, ventral view. 29) M. andersoni; 30) M. brispex; 31) M. gressitti. Abbreviations aredefined in Table 1; scale bars = 0.05 mm.

Fig. 32. Localities in Papua New Guinea from which Mecyclothorax spp. were collected and the particular species collected at each locality. 1 = Mt. Capella — M. baehri; 2 = Mt. Fugilil — M. brispex and M. medioconstrictus; 3 = Kubor Range — M. kubor; 4 = Mt. Wilhelm — M. sedlaceki; 5 = Finisterre Range — M. kavanaughi; 6 = Mt. Missim — M. gressitti; 7 = Mt. Kaindi, Edie Creek and Bulldog Road — M. andersoni, M. cuccodoroi, and M. loebli; 8 = Mt. Amungwiwa—M. amingwiwae.