Mecyclothorax papau, Liebherr, James K., 2013

Liebherr, James K., 2013, The Mecyclothorax beetles (Coleoptera, Carabidae, Moriomorphini) of Tahiti, Society Islands, ZooKeys 322, pp. 1-170 : 43-44

30. Mecyclothorax papau sp. n.

Diagnosis.

Of the four species in this group with shallow elytral striae (Figs 22 A–D), this species is characterized by the most quadrate pronotum; MPW/PL = 1.16-1.20 (N = 2). The pronotal base is relative broad; MPW/BPW = 1.42. This species also exhibits the darkest, most metallic dorsal body coloration. This comprises a forebody that is a rich rufobrunneous with melanized regions near internal apodemes - clypeus, frontoclypeal suture, and pronotal anterior transverse impression and median base - and rufopiceous elytra with narrowly paler sutural intervals and narrowly rufobrunneous lateral marginal depressions. The upraised elytral microsculpture, a mixture of isodiametric and slightly transverse sculpticells, results in a silvery metallic reflection. Setal formula 2222; standardized body length 5.5-5.9 mm. Head with frontal grooves sinuously canaliculated, slightly convergent toward frontoclypeal suture, with distinct transverse wrinkles radiating onto frons from fine carina mesad anterior supraorbital seta; eyes convex, ocular ratio 1.58-1.62, ocular lobe protruded from gena, a fine shallow groove at juncture; antennae filiform, antennomere 8 length 2.0 × maximal breadth. Pronotum with obtuse, setose hind angles, the flattened area surrounding the setal articulatory socket protruded as a jag that comprises angle; median base smooth near midline, convexly raised above basal margin and depressed relative to convex disc, juncture with disc lined with 10-12 fine, short longitudinal wrinkles each side; anterior transverse impression bordered anteriorly by a raised margin, crossed by about eight fine longitudinal strigae each side. Elytra moderately convex, the elytral striae very shallow and indistinctly punctate, the striae so shallow that punctures are intermittently isolated even on disc, intervals only slightly convex; humeri obtuse angulate, the lateral marginal depression narrow throughout length; eighth interval convexly raised, subcarinate only near elytral apex, coplanar with other intervals basad subapical sinuation; lateral elytral setae 7 + (5-6). Microsculpture of frons and vertex a well-developed transverse mesh; pronotal disc covered with a shallow transverse mesh, the sculpticells visible only outside areas of reflected light. Coloration of body dorsum somber; antennomeres 1-2 rufoflavous, 3-11 rufobrunneous; femora flavous except for apices with rufoflavous cast, contrasted with partially melanized, rufobrunneous ventral sclerites; tibiae and tarsi rufopiceous.

Male genitalia. Aedeagal median lobe robust, shaft broad; apex moderately extended beyond ostium, tip gently downturned (Fig. 24A); right paramere narrow in apical half of length, extended as a whip-like structure; internal sac with broad ventral expansion that is covered with a well-developed ventral ostial microtichial patch; flagellar plate very elongate, length 0.70 × distance from parameral articulations to apex.

Holotype male (MNHN) labeled: French Polynesia: Tahiti Nui / Pito Hiti el. 2080 m 2-VI- / 2006 lot 03 pyrethrin fog / 17°36.806'S, 149°27.842'W / E. M. Claridge // HOLOTYPE / Mecyclothorax / papau / J.K. Liebherr 2013 (black-bordered red label).

Paratype: Tahiti Nui, Pito Hiti, 2090 m el., 17°36.790'S, 149°27.842'W, 2-vi-2006 lot 02, Claridge, pyrethrin fog (EMEC, 1 teneral female).

Etymology.

The species epithet papau is the Tahitian adjective for shallow, as well as the noun for shallows. The name signifies the very shallow elytral striae observed in individuals of this species.

Distribution and habitat.

The two specimens were collected in pyrethrin fog samples of moss-covered vegetation 20-30 m elevation below the summit of Pito Hiti.