Mecyclothorax gressitti 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 : 695-697

9. Mecyclothorax gressitti Liebherr , new species ( Figs. 6 , 15–16 , 23–24 , 27 , 31 , 32 )

Diagnosis. These dark, glossy beetles are unique among the known Papua New Guinea Mecyclothorax fauna due to the presence of only one dorsal elytral seta near the anterior third. The quadrisetose pronotum appears broad, but that appearance is caused by its relatively large size and quadrate shape: MPW/PL = 1.17 (n = 2); MPW/BPW = 1.47–1.48. The pronotal median base is depressed relative to the convex disc, broadly margined laterally, and distinctly and rugosely punctate, much like that of M. kubor ( Baehr 2008, fig. 6) from Papua, Indonesia. Discal elytral striae 1–4 are shallow with elongated punctures. Striae 5–6 comprise isolated punctures and are absent from the apical third, whereas stria 7 is essentially absent, traceable only by the presence of extremely shallow inflexions of the cuticular surface. The forebody is glossy, with only indistinct transverse lines visible over portions of the frons, vertex, and pronotal disc. The elytra are subiridescent due to a mixture of mostly transverse lines not connected into a mesh plus a minority of transverse sculpticells, breadth 3–4X length. Standardized body length is 4.8–5.1 mm.

Description. Head: Gracile; small eyes protruding on extended ocular lobes ( Fig. 6 ), ocular ratio = 1.55–1.60, ocular lobe ratio = 0.79; frontal grooves deep, well-defined, arcuately convergent anteriorly from anterior supraorbital seta to deep frontoclypeal suture, then extending onto posterior portion of clypeus; ocular lobe defined posteriorly at gena by fine, shallow groove, dorsally by deep, periocular groove laterad supraorbital setae; antennomere 3 with a few fine setae basad apical ring setae; antenna robust, antennomere 9 length 1.8X maximal breadth; anterior labral margin broadly, moderately emarginate; mandibles moderately elongate, length from dorsal condyle to apex 1.6X distance from condyle to anterolateral margin of labrum; vertex flat behind eyes, not impressed; mentum tooth with sides acute, apex tightly rounded; ligular apex truncate, ligular setae separated by 3 setal diameters, paraglossae extending only 1/4 length past anterior ligular margin. Pronotum: Broad, lateral margins broadly convex; lateral setal position on inner margin of broad lateral marginal depression; hind angle a small, obtuse denticle, the basal pronotal seta slightly anterad hind angle; median base distinctly depressed with 16–18 broad shallow punctures each side, its anterior juncture with disc smooth; basal margin upraised to fine margin behind laterobasal depressions, convex medially; median longitudinal impression with narrow, deep impression at front of median base, finely incised and very shallow on disc; anterior transverse impression shallow, irregular medially, deeply incised in outer half to 2/3 of breadth each side; anterior callosity broadly, slightly convex, surface with fine, irregular longitudinal wrinkles; front angles slightly protruding, tightly rounded, marginal bead well-defined; lateral marginal depression narrow anteriorly, broader behind lateral seta, smoothly broadened to laterobasal depression, distinctly lined with microsculpture throughout its length, margin beaded anteriorly, explanate posteriorly; laterobasal depression broad, a broad convex tubercle between lateral marginal depression and punctate median base; prosternum with deep anteapical furrow that extends from lateral reaches across ventral surface, the furrow indistinctly punctate ventrolaterally; prosternum flat medially posterad anteapical furrow, convex between procoxae; proepimeron with 7 indistinct punctures in anterior groove, posterior groove smooth. Elytra: Broadly subquadrate, humeri extended laterally, maximum width posterior to midlength, disc convex medially but laterally sloping to marginal depression ( Fig. 6 ), MEW/EL = 0.76–0.77; parascutellar seta present; scutellum broad, width at transverse groove/median length = 2.0; parascutellar striole shallow, 4 shallow punctures connected or not; elytral basal groove evenly recurved anteriorly from striole, humeri obtusely angulate; striae 1–5 visible on disc, sutural stria smooth on disc, only slightly punctate basally, striae 2-5 punctate throughout basal 2/3 of length, though punctures may be variously connected or isolated by deeper or shallower strial segments; striae 6–7 represented by very isolated and shallow punctures; sutural stria present only on elytral apex, well-defined, striae 2–7 absent; stria 8 deeply impressed at midlength, though slightly irregular due to fluctuated inner margin of marginal depression; lateral marginal depression narrow throughout length, though slightly broader behind humerus; subapical sinuation broadly, slightly invaginated, epipleuron visible in anterior portion; lateral elytral setae 7 + 6; subapical elytral seta absent, apical seta in association with apex of stria 2 present. Mesepisternum: With 7 large punctures depressing surface, 3 linear punctures each side of mesosternum; metepisternum maximum width/ lateral length = 0.70; metasternal process acute, lateral margins broadly convex; metathoracic wings vestigial, apex not extending beyond posterior margin of metanotum. Abdomen: Ventrites 1 and 2 separated by broadly sinuous suture laterally, surface of ventrite 2 depressed posterad sinuosity; 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 2–3X length; pronotal disc and median base with indistinct transverse lines on a glossy surface, laterobasal depression with swirling, elongate transverse mesh; elytra with dense transverse lines partially joined into an elongate transverse mesh, surface subiridescent; elytral apex with shallow transverse mesh, sculpticell breadth 3–4X length; metasternum with indistinct transverse mesh, sculpticell breadth 2–3X length; lateral portions of basal abdominal ventrites with swirling isodiametric and transverse sculpticells. Coloration: Head rufopiceous, labrum and mouthparts rufous with piceous cast, palps brunneous; antennae rufobrunneous, antennomeres 4–11 with piceous cast; pronotal disc rufopiceous, lateral marginal depression translucent, rufoflavous where broader; elytral disc dark rufous, sutural interval concolorous, lateral marginal depression rufobrunneous; proepipleuron and proepisternum rufopiceous, lateral margin of former translucent, amber colored; elytral epipleuron rufobrunneous dorsally, dark rufous ventrally, metepisternum dark rufous; abdomen dark rufous with a piceous cast, apical half of ventrite 6 flavous; femora rufobrunneous, tibiae rufobrunneous with piceous cast.

Male Genitalia. Right (ventral) paramere narrow basally, margins subparallel for much of length, apex evenly narrowed to a tightly rounded tip ( Fig. 15 ), 9 setae along apical half of ventral margin, plus 2 stouter apical seta; left (dorsal) paramere elongate, moderately narrow basally with a long, whip-like, and attenuate apex bearing 2 apical setae ( Fig. 16 ); aedeagal median lobe stout basally, apex distinctly downturned, tip truncate with both a dorsal and ventral prominence ( Fig. 23 ); ostial triangle present at distal margin of ostial opening; flagellar plate present, appearing comparable to configuration observed in M. andersoni (e.g., Fig. 18 ); antecostal margin of 8 th mediotergite broad, nearly evenly rounded ( Fig. 24 ).

Female Reproductive Tract. Bursa copulatrix columnar ( Fig. 27 ), length about 2X maximal breadth (compressed under microslide cover slip); spermathecal duct entering bursa dorsobasally, anatomically opposite ventrobasal juncture of common oviduct and bursal base; spermathecal duct elongate, narrow, about 3X length of fusiform spermathecal reservoir; spermathecal gland duct entering at base of spermathecal reservoir; basal gonocoxite 1 with 2 apical fringe setae, an apicomedial seta, and more than 10, generally stout setae along medial surface ( Fig. 31 ); apical gonocoxite 2 broad basally due to laterally extended apodeme, with 2 gracile lateral ensiform setae, 1 similarly shaped dorsal ensiform seta, and 2 apical nematiform setae in fossa, situated 0.27X gonocoxite length from apex.

Holotype. Male with genitalia dissected and placed in polyethylene genitalia vial on pin ( BPBM): NEW GUINEA: NE / Wau Mt. Missim / 1350-1600 m. / 12.V.1967 // J. L. Gressitt / Collector / BISHOP MUSEUM // HOLOTYPE / Mecyclothorax / gressitti / J.K. Liebherr 2017 [black-bordered red label].

Paratype. Female with abdominal ventrites removed and glued to platen and reproductive tract in polyethylene genitalia vial on pin ( BPBM): NEW GUINEA NE / Mt. Missim, 2400–2800 m. / J.L. Gressitt / J. Sedlacek / Bishop // 22–30.IV.1968 .

Etymology. This species is named to commemorate J. Linsley Gressitt, whose contributions to systematic biology spanned many taxa over decades, continents, and much of the Pacific Ocean ( Radovsky 1983).

Distribution and Habitat. Mt. Missim ( Fig. 32 ) is located on the east side of the Bulolo Valley northeast of Wau ( Brass 1964, fig. 1).

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. 9–16. Mecyclothorax species, parameres, anatomically dorsal margin upward, right parameres odd numbered, left parameres even numbered. 9–10) M. kavanaughi; 11–12) M. andersoni, short aedeagal form, male 02; 13–14) M. andersoni, long aedeagal form, male 06; 15–16) M. gressitti.

Figs. 17–24. Mecyclothorax andersoni: 17) Male 8, VSB form, aedeagal median lobe and parameres, internal sac everted, right view; 18) Male 2, MEB form, aedeagal median lobe and parameres, right view; 19) Male 2, mediotergite IX plus rounded antecostal apodeme, short apex form, dorsal view; 20) Male 9, EDR form, aedeagal median lobe and parameres, internal sac everted, right view; 21) Male 3, VEN form, aedeagal median lobe and parameres, right view; 22) Male 3, mediotergite IX plus rounded antecostal apodeme, long apex form, dorsal view. Mecyclothorax gressitti: 23) Male aedeagal median lobe and parameres, right view; 24) Male mediotergite IX plus rounded antecostal apodeme, dorsal view. Abbreviations are defined in Table 1.

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.