Uenoites tibialis, Belousov & Kabak & Schmidt, 2019

Belousov, Igor A., Kabak, Ilya I. & Schmidt, Joachim, 2019, Two new species of the genus Uenoites Belousov et Kabak, 2016 from mountains of Myanmar (Coleoptera: Carabidae: Trechini), Zootaxa 4544 (1), pp. 103-112 : 108-111

Uenoites tibialis sp. n.

( Figs 2 , 4 , 9, 10 , 13 )

Type material. Holotype: MYANMAR: 1 female, with label data “N Burma, leg. Reuter, ca. 75 km NW Putao , 3700 m NN, 10.08.2006 ” (coll. J. Schmidt).

Remarks. A thorough examination of all available specimens of the Uenoites collected by Christoph Reuter has revealed that one female differs clearly from three other specimens in a number of correlated characters. The level of these differences substantially exceeds intraspecific variability observed in species of the genera Uenoites , Queinnectrechus and other allied taxa. Moreover, two or three sympatric species of Uenoites with similar morphological differences are the rule rather than the exception for large mountainous areas between valleys of Yangtze and Nujiang rivers. Therefore, we decided to describe this species even though only a single female specimen is available.

Description. Habitus: rather large-sized species, body length 4.96 mm. Body elongate and convex, with relatively wide pear-shaped elytra and narrow head and pronotum, the latter markedly constricted at base, its hind angles acute and distinctly attenuated outwards and backwards; dorsal surface shining, appendages rather long and robust ( Fig. 2 ).

Color: dark, pitchy-blackish, with faint metallic luster; most of head, mandibles and appendages, base and anterior part of pronotum, base of elytra, their margins and suture reddish; labrum darkened medially. Femora and distal portions of tibiae infuscate, antennae barely obscured beginning with antennomere 4.

Microsculpture: reduced; micropunctation extremely fine but dense and perceptible throughout the whole dorsum, dispersed in irregular agglomerations. Ventral surface of abdominal sternites mostly smooth and shining except for the median area, which is covered with microsculpture.

Head: medium-sized, PW/HW 1.23, slightly depressed; eyes conically convex, medium-sized (L3/EyL 1.22), distinctly longer than tempora (EyL/TL 1.31); latter flat, linearly convergent posteriad, glabrous. Frons convex, with a few transverse wrinkles in median portion. Frontal furrows faintly arcuate, subparallel for most of their length, markedly deeper behind middle; parietal impression rather distinct. Supraorbital setiferous pores located on lines subparallel to longitudinal axis of body, anterior one slightly foveolate, posterior one shallowly impressed. Labrum moderately concave, its anterior margin with five setae, this number seemingly aberrant. Mandibles rather slender, moderately curved, tooth on the right mandible with premolar fused with retinaculum, tridentate, oblique, its basal margin rather short; proximal denticle markedly produced, approximately as long as distal one; median denticle much shorter. Mentum fused with submentum, submental suture indistinct. Six submental setae, of which subangular ones are slightly shorter than median setae. Labial tooth very short, transverse, truncated apically, without emargination, not distinctly margined basally. Palpi moderately slender. Antennae of medium length, a little longer than elytra, AL/EL 1.11; middle antennomeres much longer than wide, L3/ W3 3.14; L3/L2 1.47.

Pronotum: elongate, nearly as long as wide (PW/PL 1.03), convex and cordiform, its maximum width in anterior third, markedly constricted towards base (PW/PB 1.56). Hind angles acutangular, produced back- and outwards. Lateral border and lateral groove very narrow, not reaching the anterior margin of pronotum ( Fig. 4 ). Both lateral border and marginal groove completely disappearing posterior to mid-length of pronotum. Basal margin slightly convex medially, emarginated laterally; anterior margin straight; anterior angles completely rounded off and even shifted posteriad. Prebasal transverse impression exceptionally shallow for most of its length; basal surface smooth. Basal foveae rather small, deep, their bottom smooth. Apical transverse impression, at most, traceable medially. Discal foveae lacking. Median line shallowly impressed, distinct only in median portion, without basal impression. Two lateral setiferous pores on each side of pronotum, anterior one in anterior third (32% of pronotal length), posterior one markedly shifted anteriad from hind angles.

Elytra: relatively small (EL/PL 2.42, EW/PW 1.78, EW/HW 2.20), short (EL/EW 1.32), rather convex (EL/BH 1.96), oblong-ovate, with maximum width slightly behind their mid-length. Basal portion distinctly elongate and therefore humeral group of umbilicate series markedly shifted posteriad. Disc slightly depressed along suture, more distinctly in posterior half, convex laterally. Humeri oblique. Apices of elytra conjointly rounded, faintly attenuated at summit. Preapical sinuation distinct. Lateral groove narrow. Striae of elytra reduced, only fragments of striae 1–3 traceable, mostly in middle part. Interspaces flat. Parascutellar striole vague and shallow, becoming distinctly visible only under certain lighting. Apical striole short, evenly curved. Four to six foveolate discal setiferous pores, of which the posterior one (preapical pore) is most isolated and located symmetrically on both elytra in the sinuation of stria 2, approximately at level of umbilicate pore 8 (88% of elytral length), slightly before level of the anterior termination of apical striole. All other pores attached to stria 3, rather variable in position though pores 1–2 are most approached; posterior true discal (not preapical) pore located at different levels on left and right elytra. Apical triangle moderately elongate, its inner side subparallel to body axis; angulo-apical seta much shorter than other setae of apical triangle, located much closer to suture than to the exterior pore on the left elytron and approximately in middle on the right one. Median pair of umbilicate series far behind mid-length of elytra though clearly spaced from preapical pair. Umbilicate formula: 16, 20, 24, 29, 60, 64, 77, 86, thus umbilicate pores 7 and 8 much more distant from each other than pores within other groups of umbilicate series. All pores of the umbilicate series located approximately at the same distance from the lateral margin, only umbilicate pore 1 faintly shifted inward.

Ventral side: metepisternites rather short, though markedly longer than wide. Suture between abdominal sternites III and IV completely effaced medially. Two paramedian setae on visible sternites IV–VI. Two pairs of setae along the posterior margin of the anal sternite in only one known female specimen. Anal sternite with a large median fovea and two smaller lateral foveae.

Legs: relatively long, with protibiae and mesotibiae nearly straight, rather thin, and with metatibiae sinuate, markedly inflated inwardly in apical third, truncated and incised on inner edge apically ( Figs 10 , 13 ), with a small tooth right in inner angle; adjacent inner surface covered with a dense brush of yellowish hairs. Similar incision, though less developed, is present in mesotibiae. Metatarsi relatively long (HTi/HTa 1.23). Hyaline appendages of the fourth pro- and mesotarsomeres distinctly dilated in median portion and not reaching the apical margin of tarsomere 5. First segment of metatarsi as long as three following segments combined (ratio 1.0–1.02).

Comparative notes. Uenoites tibialis sp. n. is very similar to U. reuteri sp. n. but may be easily diagnosed by the following combination of characters: color of body with more pronounced reddish tinge, especially femora less obscured as compared with rather dark tibiae; pronotum elongate, nearly as long as wide (PW/PL = 1.03, while this ratio is more than 1.10 in U. reuteri sp. n.; PW/HW 1.23 vs. 1.32–1.35; EW/PW 1.78 vs. 1.64–1.73); hind angles of pronotum acutangular, produced backwards and outwards (while subrectangular and slightly produced, though highly variable in U. reuteri sp. n.); basal part of elytra elongate, therefore humeral group of umbilicate series markedly shifted posteriad as compared with U. reuteri sp. n. (U1–U 4 16, 20, 24, 29 vs.12, 15, 19, 25); humeral group of umbilicate series well-aggregated, umbilicate pore 1 barely shifted from lateral margin compared with other umbilicate pores of humeral group, while markedly removed from lateral margin in U. reuteri sp. n.; first segment of metatarsi as long as three following segments combined (1.00–1.02) while markedly shorter in U. reuteri sp. n. (corresponding ratio 0.81–0.84). The most important diagnostic feature of U. tibialis sp. n. is a peculiar structure of the hind tibiae with an inner hairy brush and an emargination in the apical third ( Fig. 13 vs. Fig. 12 ).

Apart from the above listed characters, there are some other morphometric differences which seem to be of minor importance and probably will not be confirmed with additional material, though most ranges are not overlapping for two species: eyes smaller (EyL/TL 1.31 vs. 1.50–1.64; L3/EyL 1.22 vs. 0.94–1.17); antennae longer (AL/EL 1.11 vs.0.94–0.99; L3/ W3 3.14 vs. 2.70–2.91); elytra shorter and less convex (EL/EW 1.32 vs. 1.38–1.46; EL/PL 2.42 vs. 2.66–2.72; EL/BH 1.96 vs. 2.05–2.16); hind tarsi longer (HTi/HTa 1.23 vs. 1.38–1.41). Most of these features seem to suggest a more cryptozoic mode of life for U. tibialis sp. n.

Distribution. Probably endemic to the mountain range located ca. 70–75 km NW of Putao in northern Myanmar.

Habitat. The species was found in the cloud forest zone at an elevation of 3700–3900 m a.s.l.

Etymology. The species’ epithet refers to the peculiar structure of hind tibiae which is an important diagnostic feature of the new species.

Figures

FIGURES 1–2. Uenoites Belousov et Kabak, 2016, habitus, holotypes. 1, U. reuteri, sp. n.; 2, U. tibialis sp. n.

FIGURES 3–5. Lateral border and marginal groove of pronotum. 3, Uenoites reuteri sp. n.; 4, U. tibialis sp. n.; 5, Queinnectrechus globipennis Uéno, 1998.

FIGURES 9–10. Uenoites tibialis sp. n. 9, fore tibia; 10, hind tibia.

FIGURES 12–13. Uenoites Belousov et Kabak, 2016, hind tibiae. 12, U. reuteri, sp. n.; 13, U. tibialis sp. n.