Batriscenellus suthepensis Yin & Kleeberg, 2020

Yin, Zi-Wei & Kleeberg, Andreas, 2020, Two new species of Batriscenellus Jeannel from tropical Asia (Coleoptera Staphylinidae: Pselaphinae), Zootaxa 4822 (1), pp. 121-126 : 122-124

Batriscenellus suthepensis Yin & Kleeberg , sp. nov.

( Figs 1A , 2 )

Type material. HOLOTYPE: THAILAND: ♂, ‘N-Thailand, Chiang Mai, Doi Suthep National Park , Nov. 2019 / Mok Fa waterfall, leaf litter, 08.11.2019, leg. Kleeberg’ ( MNB). PARATYTYPES: THAILAND: 1 ♂, 4 ♀♀, same collection data as holotype ( MNB, SNUC).

Diagnosis. Male: dorsal surface of head and pronotum finely punctate. Head with thick median carina extending from posterior margin of vertex to above anterior margin of eyes; trichomes on anterolateral margins of antennomeres 1 small, indistinct. Pronotum with strongly sinuate lateral longitudinal sulci. Abdominal tergite 1 (IV) broadly and shallowly impressed in posterior half, surface of impression densely covered with short setae. Aedeagus with large basal capsule and strongly twisted, broad dorsal lobe. Female: genital complex of unique form.

Description. Male ( Fig. 1A ). Body reddish-brown, length (from anterior margin of clypeus to posterior margin of abdomen) 1.98–2.04 mm. Head sub-quadrate, length from anterior margin of clypeus to posterior margin of vertex 0.44–0.45 mm, width across eyes 0.46 mm; dorsal surface ( Fig. 2A ) smooth and finely punctate, frons rough; antennal tubercles moderately prominent; vertexal foveae nude, distinct, situated at level of middle of eyes, anterior margin of vertexal sulcus straight; antennae elongate, length 1.02 mm, clubs weakly indicated by apical three antennomeres; ocular-mandibular carina distinct; eyes strongly prominent, each composed of 30 large ommatidia. Pronotum ( Fig. 2A ) about as long as wide, length along midline 0.47 mm, maximum width 0.45 mm; disc finely punctate; lateral longitudinal sulci strongly sinuate; with two small, acute antebasal denticles. Elytra slightly wider than long, length along suture 0.65–0.66 mm, maximum width 0.74–0.77 mm; discal striae extending to apical 4/5 of elytral length; with distinct humeral calli; with complete marginal striae originating from small subhumeral foveae. Legs elongate and slender, apical portions of pro- and metafemora with short sensory setae. Abdomen ( Fig. 2B ) wider than long, length along midline 0.54 mm, maximum width at base of tergite 1 (IV) 0.66 mm; tergite 1 (IV) longer than 2–4 (V–VII) combined, with broad and shallow impression occupying posterior half of tergite, surface of impression covered with dense, short setae; discal carinae lengthily triangular, widely separated; single marginal carina extending posteriorly to half of tergal length; weakly sclerotized sternite 7 (IX) ( Fig. 2C ) transverse, suboval. Aedeagus ( Fig. 2 D–F) asymmetric, length 0.24 mm; basal capsule (slightly collapsed in Fig. 2 ) strongly dilated; ventral lobe short and broad, expanded at apex; dorsal lobe much longer and wider than ventral lobe, strongly curved ventrally and narrowed at apex; parameres fused to form short ventral membrane.

Female. Similar to male in general appearance and size. Antennae slightly shorter. Each eye composed of 23 facets. Tergite 1 (IV) lacking modification. Genital complex as in Fig. 2G , length along midline 0.22 mm, maximum width 0.24 mm. Measurements of body segments (as for male): body length 1.99–2.02 mm, length of antennae 0.94 mm, length/width of head 0.39–0.43/ 0.43–0.45 mm, pronotum 0.43–0.44/ 0.44–0.47 mm, elytra 0.54–0.55/ 0.69– 0.70 mm, abdomen 0.55–0.58/ 0.65 mm.

Comments. The new species is distinct, and can be readily separated from all congeners by the unique forms of the broad, shallow cavity of tergite 1 (IV) ( Fig. 2B ) of the male, and genital complex of the female.

Distribution. Thailand: Chiang Mai.

Etymology. The new specific epithet refers to Suthep National Park, type locality of the new species.

Figures

FIGURE 1. Habitus of Batriscenellus species. A. B. suthepensis. B. B. vietnamicus. Scale bars: 0.5 mm.

FIGURE 2. Diagnostic characters of Batriscenellus suthepensis (A–F. Male. G. Female). A. Head and prothorax, dorsal. B. Abdomen, dorsal. C. Sternite 7 (IX). D–F. Aedeagus, in axial (D), lateral (E), and ventral (F) view. G. Genital complex. Scale bars: 0.2 mm in A, B; 0.05 mm in C; 0.1 mm in D–G.