Onycholabis stenothorax Liang and Kavanaugh

Liang, Hongbin & Kavanaugh, David H., 2005, A Review of Genus Onycholabis Bates (Coleoptera: Carabidae: Platynini), with Description of a New Species from Western Yunnan, China, The Coleopterists Bulletin 59 (4), pp. 507-520 : 514-516

Onycholabis stenothorax Liang and Kavanaugh , new species

( Figs. 6–11 )

Types. Holotype, a male, in IOZ, labelled: ‘‘ China, Yunnan Province, Tengchong, Qushi Town, Xiangyangqiao , riverside, 25812938.40N, 98834949.40E’’/‘‘ 1,515 m, 2003.10.23, night, Liang H. B., Shi X. C. Coll., Institute of Zool. , CAS & California Acad. Sciences’ ’/‘‘ HOLOTYPE Onycholabis stenothorax Liang & Kavanaugh’’ [red label]. Paratypes: 6 males and 1 female, same data as holotype ; 2 males and 2 females, ‘‘ China, Yunnan Province, Longling, Zhen’an Town, Bangbie , along a stream, 24848947.40N, 98849959.10E’’/‘‘ 1,540 m, 2003.10.30, day, Liang H. B., Shi X. C. Coll., Institute of Zool. , CAS & California Acad. Sciences’ ’; 2 females, ‘‘ China, Yunnan Province, Tengchong, Wuhe Town, Zhengding , stream side, 24850946.20N, 98845914.50E’’/‘‘ 1,985 m, 2003.10.29, day, Liang H. B., Shi X. C. Coll., Institute of Zool., CAS & California Acad.Sciences’ ’. Among the 13 paratypes, five specimens are deposited in CAS, six in IOZ, and two in KIZ .

Type Locality. Qushi , Tengchong County, Baoshan Prefecture, Yunnan Province, China .

Diagnosis. This new species seems to be most closely related to O. melitopus Bates and O. nakanei Kasahara , based on chaetotaxy of the pronotum; but adults are readily distinguishable from those of O. melitopus by the rounded elytral apices at the sutural angles, and from those of O. nakanei by the narrow pronotum and reduced number (2 in males and 6 in females) of marginal setae on the sixth visible sternum.

Description. Body length 10.7–12.0 mm (including mandibles). Width: 3.4–3.9 mm. Body black, shiny dorsally; mandibles, labrum and mentum red-brown; antennae, palpi and legs light brown.

Head with large and markedly prominent eyes and markedly constricted neck; vertex slightly convex above with surface very smooth and shiny, microsculpture partly and sparsely visible and formed of isodiametric meshes; frontal furrows deeply concave, almost parallel anteriorly and slightly divergent posteriorly, surface laterad of frontal furrows longitudinally rugose; anterior supraorbital seta inserted anterior to mid-eye level, posterior supraorbital seta inserted slightly anterior to post-eye level; mandibles long, slender, gently curved inwards and gradually tapered towards tips [which are not as sharply pointed as in other species]; terminal maxillary palpomeres slender, almost as long as penultimate palpomeres, cylindrical in median portion and truncate at apices; terminal labial palpomere shorter than penultimate; penultimate palpomeres bisetose; median tooth of mentum bifid, with each apex sharply pointed; submentum quadrisetose; antennae filiform, extended to middle of elytra; relative lengths of scape and antennomeres II–VI as follows: 1.0: 0.44: 1.65: 1.51: 1.14: 1.14.

Pronotum cordate, longer than wide, widest at about apical one-third, narrower than head, PW/ HW ¼ 0.89 (0.85–0.92), PW/PL ¼ 1.05 (0.98–1.10), PW/PAW ¼ 1.34 (1.29–1.39), PW/PBW ¼ 1.47 (1.41–1.55); apical margin widely and rather shallowly emarginate throughout; front angles rounded, obtuse at tips; lateral margins finely reflexed, arcuate before widest parts, rather gradually convergent to basal one-sixth, then slightly sinuate anterior to rectangular, pointed hind angles; 1 pair of marginal setae inserted slightly before widest part; basal margin distinctly bisinuate and unbordered throughout; disc moderately convex above, with surface smooth, except for sparse and scattered large punctures along basal and lateral portions, microsculpture evident as transverse meshes; median longitudinal furrow narrow but distinctly impressed throughout, basal foveae deep.

Elytra subovate, moderately convex above, widest slightly behind middle, much wider than pronotum, EL/EW ¼ 1.73 (1.64–1.77), EW/PW ¼ 1.89 (1.83–1.92); basal margination short and slightly curved; basal margins wide, oblique and extended to humeri, which are distinct but rounded; lateral margins almost parallel-sided in basal portions, moderately convergent towards apices, slightly but distinctly produced just before apices which are conjointly rounded; scutellar striole long, extended onto interval I and punctate; striae between intervals deeply impressed, with regularly spaced punctures except indistinctly punctate in apical portion; intervals smooth, with microsculpture evident as transverse meshes, slightly convex in apical half and flatter towards apex; interval III with 1 setiferous pore puncture at basal one-fifth near stria III and a second just behind middle and near stria II (2 specimens with 3 pore punctures on one elytron).

Prosternum, lateral portions of metaternum and pro- and metepisterna coarsely punctate. Sixth visible sternum with 2 marginal seta in male, 6 in female.

Legs long and slender; protarsomeres I–III slightly dilated in male, with two rows of adhesive hairs on ventral side; tarsomere IV bilobed apically.

Male genitalia with aedeagus long and slender, slightly arcuate at basal one-third in lateral view, then almost straight toward rounded apex ( Fig. 7 ); in dorsal view, apical lamella slightly tapered towards apex, nearly as long as wide ( Fig. 8 ); left paramere broadly subovate and rounded at apex ( Fig. 9 ); right paramere small and narrow, with rounded apex ( Fig. 10 ).

Female reproductive tract as in Figure 11 ; basal gonocoxite I with apical fringe of 13 setae; apical gonocoxite II with 7 dorsolateral and 1 dorsomedial ensiform setae; bursa copulatrix without microtrichia, spermatheca slightly arcuate, spermathecal gland with spherical apex.

Distribution. Presently known from Tengchong, Baoshan and Longling counties, on both western and eastern slopes of the Gaoligong Mountains in western Yunnan Province, China.

Etymology. This new species is named for its narrow pronotum.

Figures

Figs. 5–6. Dorsal habitus of Onycholabis species, scale line ¼ 1.0 mm. 5) O. pendulangulus;

Figs. 7–11. Onycholabis stenothorax n. sp. 7) aedeagus, left lateral aspect; 8) apex of aedeagus, dorsal aspect; 9) left paramere, lateral aspect; 10) right paramere, lateral aspect; 11) female reproductive tract, ventral aspect; scale lines for Figures 7–10 ¼ 0.2 mm, for Figure 11 ¼ 0.5 mm.