Onycholabis Bates 1873

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 : 508

Genus Onycholabis Bates 1873

Type Species. Onycholabis sinensis Bates, 1873:329 ( Sze-Chuen ¼ Sichuan), by original monotypy .

Description. Medium size, body length 9.0– 12.5 mm (including mandible). Black, except brown in teneral individuals; mandibles, labrum and mentum red-brown, palpi, legs and antennae pale yellow to brown. Microsculpture on head and base and lateral margins of pronotum formed of isodiametric meshes (less distinct on head), on disc of pronotum and elytra formed of transverse meshes. Mandible long, slightly narrow, and straight, with apex sharply pointed and markedly hooked medially ( Fig. 1 ); antennae long, extended beyond humerus to about middle of elytra, antennomeres III–XI pubescent, antennomere III about 4 times as long as antennomere II, about 1.7–1.8 times as long as scape; eye large, hemispherical; tempora half as long as longitudinal diameter of eye; anterior and posterior supraobital setae present; frontal fovea deep; vertex slightly convex, glabrous; mentum with prominent, bifid tooth; submentum with 1 long seta and 1 short seta on each side; glossal sclerite with apex slightly rounded, with 2 long setae at subapex; paraglossa membranous, shorter than and fused with glossal sclerite. Pronotum trapezoidal ( Fig. 1 ) or cordate ( Fig. 2 ), glabrous; basal angle nearly rectangular, with 1 or without seta; basal fovea narrow and deep, rugosely punctate; lateral margin with 1 seta before the middle; prosternal process round at apex, unbordered. Elytra glabrous, shining; striae deep, punctate in basal three-fourths; intervals flat or slightly convex, impunctate, interval III with 2 or 3 setiferous pore punctures; scutellar striole long, scutellar pore puncture present. Legs long and slender; tibia slender, not dilated at apex; tarsomeres with both medial and lateral longitudinal sulci dorsally, tarsomere IV bilobed, tarsomere V asetose ventrally; tarsomeres I–III slightly dilated in male, longer than wide, with adhesive setae on ventral side; claws simple.

Biology. The adults of all Onycholabis species apparently are hygrophilous. They are often found at night walking on the rocky walls of drainage ditches or along the margins of small streams, on river banks, or in the splash zones of waterfalls.

Geographical Distribution. Eastern and southeastern Asia; presently known from India, Sikkim, Bhutan, Assam, Myanmar, Laos, Vietnam, China, South Korea, and Japan.

Figures

Figs. 1–4. Dorsal habitus of Onycholabis species, scale line ¼ 1.0 mm. 1) O. acutangulus