Smetanabatrus loebli, Yin & Cuccodoro, 2018

Yin, Zi-Wei & Cuccodoro, Giulio, 2018, Notes on Smetanabatrus from Southeast Asia (Coleoptera: Staphylinidae: Pselaphinae), Revue suisse de Zoologie 125 (2), pp. 245-248 : 245-247

Smetanabatrus loebli sp. nov.

Figs 1-2

Type locality: Genting Highlands , Pahang, Peninsular Malaysia .

Type material (2 ex.): Holotype, MHNG- ENTO-00013301; ♂; W. Malaysia # 28, Pahang, Genting Highlands, Awana , 950 m; 4.iv.93; coll. Löbl; veg. debris; “ HOLOTYPE (red, printed), Smetanabatrus loebli Yin & Cuccodoro 2018 ” . – Paratype: MHNG-ENTO-00013318; ♀; Malaysia, Malaya, Fraser’s Hill , 1500 m; 11.iii.(19)90; coll. Rougemont; “ PARATYPE (yellow, printed), Smetanabatrus loebli Yin & Cuccodoro 2018 ” .

Diagnosis: Body medium-sized, length 2.66-2.79 mm. Head and pronotum regularly punctate, anterior margin of clypeus angularly projecting anteriorly at middle. Pronotum with thin discal carinae, with distinct median and lateral sulci. Maxillary palpomere IV greatly lobed at inner margin. Distinct ocular canthus present. Males have abdominal tergite 1 (IV), and sternite 3 (V) modified; protrochanter protuberant at ventral margin, metatibia strongly dilated at apical portion; aedeagus with large and transverse basal capsule, median lobe slightly asymmetric.

Description: Male ( Fig. 1A ). Body length (combined length of head, pronotum, elytra, and abdomen) 2.66 mm. Body reddish brown, tarsi and mouthparts lighter in color. Head distinctly transverse, length from clypeal anterior margin to head base 0.55 mm, width across eyes 0.71 mm; surface regularly punctate; vertex convex, foveae far below level of posterior margins of eyes, lacking reverse U-shaped sulcus connecting foveae, thin median carina present from base toward apex of frons, anterior margin of clypeus angularly protuberant ( Fig. 1B ; ap) at middle; eyes moderately prominent, longitudinal length 0.15 mm, each eye composed of about 45 facets; with short ocular canthus ( Fig. 1C ; oc); maxillary palpus with palpomere IV greatly lobed on inner margin ( Fig. 1C ; mp4); length of antenna 1.85 mm; antennomeres each elongate, club indistinct ( Fig. 1A ). Pronotum nearly cordiform, about as long as wide, length along midline 0.60 mm, maximum width 0.64 mm, regularly punctate; with triangular antebasal spines, deep median and thinner lateral sulci, and slightly curved discal carinae on disc; lateral margins rounded on apical half, straight and nearly parallel from middle toward base. Elytra slightly wider than long, length along suture 0.88 mm, maximum width 1.00 mm; surface finely punctate; with three large, deep basal foveae, thin and shallow discal sulcus extending just past half elytral length. Legs moderately elongate; protrochanter with large flatten projection ( Fig. 1D ; vp) on ventral margin, protibia ( Fig. 1A ) with lateral margin slightly expanded near middle; metatibia ( Fig. 1E ) greatly dilated laterally on apical third, expansion broadly concaved on ventral surface. Abdomen much wider than long, length of dorsally visible part along midline 0.63 mm, maximum width 0.90 mm; tergite 1 (IV) longest, at basal half with transverse oval patch ( Fig. 1G ; pa) slightly raised, maximum diameter of patch 0.14 mm, area lateral to midline moderately raised ( Fig. 1F ; indicated by red arrows); tergites 2-4 (V-VII) unmodified, with tergite 4 longer than tergites 2 and 3; sternite 3 (V) with reniform (in ventral view) median protuberance ( Fig. 1F, 1H ; mp) strongly projecting ventrally. Aedeagus ( Fig. 1I ) slightly asymmetric, length 0.33 mm; basal bulb transverse, with large foramen; ventral lobe elongate, broad at base, narrowing at middle, and then roundly expanded toward apex.

Female. Similar to male in external morphology, except having unmodified legs and abdominal segments, slightly shorter antennae, and smaller eyes each composed of about 25 facets. Measurements (as for male): Body length 2.79 mm; head length 0.55 mm, width 0.68 mm; length of eye 0.14 mm; length of antenna 1.59 mm; length of pronotum 0.59 mm, width 0.66 mm; length of elytra 0.80 mm, width 0.95 mm; length of abdomen 0.85 mm, width 0.89 mm.

Comments: Several shared features, i.e., the slightly expanded outer margin of the protibia, modified male tergite 1 (IV), and strongly dilated male metatibia suggest that the new species may be more closely related to S. kinabalu from Borneo than to S. ghecu from Myanmar. Males of the latter species have the protibia slightly broadened on inner margin, and have unmodified tergite 1 (IV) and metatibia. Separation of the males of these three species may be accomplished by using the key presented below.

Biology: According to unpublished MHNG field notes, #28 on the label of the holotype indicates that the individual was sifted from an accumulation of branches and bamboo leaves in a rather dry forest

Distribution: West Malaysia (Pahang; Fig. 2 ).

Etymology: The new species is named after Ivan Löbl (Geneva, Switzerland), who collected the single male.

Figures

Fig. 1. Smetanabatrus loebli male. (A) Dorsal habitus. (B) Head dorsum. (C) Anterolateral view of head, showing form of maxillary palpomere IV and ocular canthus. (D) Protrochanter and profemur. (E) Metatibia. (F) Lateral view of abdomen, showing projections on tergite 1 (IV) and sternite 3 (V). (G) Tergite 1. (H) Median projection of sternite 3, in ventral view. (I) Aedeagus, in ventral view. Scale bars: 1 mm in A; 0.2 mm in B-H, 0.1 mm in I. Abbreviations: ap – apical protuberance, mp – median projection, mp4 – maxillary palpomere IV, oc – ocular canthus, pa – patch, vp – ventral projection.

Fig. 2. Distribution of Smetanabatrus species. 1 – S. kinabalu, 2 – S. ghecu, 3 – S. loebli sp. nov. Circles are published records, squares represent new data.