Feabatrus leonardoi, Zhang & Yin, 2023

Zhang, Wen-Xuan & Yin, Zi-Wei, 2023, Feabatrus gen. nov., a conspicuous new genus of Batrisitae from Myanmar and China (Coleoptera: Staphylinidae: Pselaphinae), Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 63 (1), pp. 165-175 : 171-174

Feabatrus leonardoi sp. nov.

( Figs 5 , 6A–D )

Chinese common name: NJKflüm

Type material. HOLOTYPE: MYANMAR: J, ‘ Carin Chebà , 500–1000 m (approximate coordinate: 19°11’N, 96°53’E), L. Fea. XII. (18)87. / Museo Civico di Genova’ ( MSNG) . PARATYPES: MYANMAR: 7 JJ 6 ♀♀, same data as that of holotype ( MSNG, SNUC).

Diagnosis. Male. Habitus elongate; body length 3.28–3.34 mm; dorsal surface of body and antennae with long suberect setae. Head sub-rounded at base, narrower than pronotum, tempora moderately long, vertex with long mediobasal carina extending anteriorly to frons, with distinct lateral carina from head base to posterior margin of antennal tubercle; antenna elongate, lacking modification. Pronotum with laterally carinate median and lateral longitudinal sulci, with pair of curved discal carinae, with large discal, antebasal and marginal spines. Elytron sparsely punctate, disc smooth, shiny, discal stria extending posteriorly to approximately 1/3 of elytral length. Legs elongate, mesotrochanter with short ventral spine, mesotibia with small apical spur; metatrochanter with long hook-like projection. Abdomen normal, slightly curved ventrally. Aedeagus asymmetric; median lobe with large basal capsule and foramen, ventral stalk narrowed apically, with two thin and elongate sclerites before apex; dorsal lobe short, recumbent; endophallus armature extremely slender and curved; parameres reduced to single membranous structure, sclerotized near base.

Female. Body length 3.28–3.43 mm. Head with long vertexal mediobasal carina extending from head base anteriorly to sulcus. Legs lacking modification. Tergites 2–4 (V–VII) lacking dorsal spine. Genital complex asymmetric, shape as in Figure 6D .

Description. Male. Body ( Fig. 5A ) length 3.28–3.34 mm; color reddish-brown, tarsi and mouthparts lighter. Dorsal surface of body and antennae covered with long suberect setae.

Head ( Fig. 5B ) sub-rounded at base, wider than long, length 0.64–0.65 mm, width across eyes 0.74–0.76 mm; vertex with U-shaped sulcus connecting relatively small, but distinct asetose foveae (dorsal tentorial pits), anterior margin of vertexal sulcus carinate, mediobasal carina long, extending anteriorly from head base to anterior part of frons, lateral carina thick, extending from posterior margin of antennal tubercle towards postocular margin; posterolateral margin weakly angulate; frons demarcated from clypeus by irregular carinae merged in middle and extending anteriorly to apex of clypeus, area between moderately raised antennal tubercles impressed; clypeus with rough surface, its entire anterior margin strongly carinate and moderately raised; ocular-mandibular carina complete. Venter with granulate surface; small gular foveae (posterior tentorial pits) originating from shared transverse opening, with thin median carina extending from opening anteriorly to mouthparts. Compound eyes prominent, each composed of approximately 65 ommatidia. Antenna elongate, lacking distinct club or modification, length 1.99–2.12 mm; antennomere 1 thick, subcylindrical, 2 as long as 8, shortest, slightly longer than wide, 3–7 each elongate, 9–11 slightly broad, with relatively dense setae, 11 largest, as long as 9 and 10 combined (39:39), nearly fusiform.

Pronotum ( Fig. 5B ) wider than long, length 0.70–0.73 mm, width 0.88–0.89 mm, widest in middle; lateral margin with small denticles in apical 1/2, convergent apically and basally; disc slightly convex, broad median longitudinal sulcus with prominent carinate margins, posteriorly confluent with median antebasal fovea and short mediobasal carina, with pair of curved discal longitudinal carinae connecting large discal and antebasal spines; lateral longitudinal sulcus thick and long; with dense pubescence lateral to sulcus; with pairs of large marginal spines; lateral antebasal foveae large and asetose; with distinct outer and inner pair of basolateral foveae. Prosternum with anterior part longer than coxal part, with small but deep lateral procoxal foveae; distinct hypomeral carina extending from base to level of lateral procoxal foveae, with two pairs of lateral antebasal hypomeral pits; margin of coxal cavity moderately carinate.

Elytra slightly wider than long, length 0.88–0.96 mm, width 1.05–1.10 mm; each elytron with three moderately large, asetose basal foveae; discal stria shallow, extending posteriorly from outer basal fovea to approximately 1/3 of elytral length; humerus roundly prominent, lacking subhumeral fovea, thin, carinate marginal stria extending from basal 4/5 to posterior margin of elytron.

Mesoventrite short, demarcated from metaventrite by oblique carinae lateral to mesocoxal cavity; median mesoventral foveae moderately separated, originating from shared transversal opening, large lateral mesoventral foveae forked internally, with short mesoventral process, with complete marginal stria. Metaventrite moderately projected admesally, inclined towards middle, with well- -developed lateral mesocoxal and two lateral metaventral foveae, posterior margin with deep, narrow split in middle.

Legs elongate, mesotrochanter ( Fig. 5C ) with short ventral spine, mesotibia ( Fig. 5D ) with small apical spur; metatrochanter ( Fig. 5E ) with long hook-like ventral projection, ventral margin of projection with long thickened seta.

Abdomen slightly elongate, widest at lateral margins of tergite 1 (IV), length 1.19–1.24 mm, width 0.91–0.93mm. Tergite 1 (IV) approximately 1.6 times as long as 2 (V), lacking basal sulcus, with one pair of mediobasal and two pairs of basolateral foveae, with pair of short, nodule-like discal carinae, inner marginal carinae thin and complete; outer marginal carinae thick, present in basal 1/2; tergite 2 approximately 1.5 times as long as 3 (VI), 3 as long as 4 (VII), 2–4 each with one pair of basolateral foveae and thin marginal carinae; tergite 5 (VIII) semicircular ( Figs 5F, G ), posterior margin broadly and moderately deeply emarginate in middle. Sternite 2 (IV) with one pair of mediobasal and three pairs of basolateral foveae, lacking lateral carina; midlength of sternites 2–5 (IV–VII) gradually shorter, each with one pair of small basolateral foveae, sternite 6 (VIII) transverse ( Fig. 5H ), barely impressed in middle, posterior margin slightly protruding in middle, sternite 7 (IX) ( Fig. 5I ) composed of pair of triangular, membranous structures.

Aedeagus ( Figs 5J–L ) 0.54 mm long, asymmetric, stout; median lobe with large basal capsule and foramen, basoventral projection short; ventral stalk narrowed apically, with two thin, elongate sclerites before apex; dorsal lobe short and recumbent; endophallus armature extremely elongate and curved; parameres reduced to single membranous structure, sclerotized near base.

Female. Similar to male externally( Fig. 6A ). Head with shorter mediobasal carina extending from head base anteriorly to sulcus. Antenna slightly shorter. Each compound eye composed of approximately 55 ommatidia; legs lacking modification; tergite 5 (VIII) weakly arched ( Fig. 6B ), sub-trapezoidal, posterior margin shallowly emarginate; sternite 6 (VIII) transverse ( Fig. 6C ), posterior margin broadly emarginate, with pair of small projections in middle. Measurements (as for male): body length 3.28–3.43 mm; length/width of head 0.62–0.64/ 0.73–0.74 mm, pronotum 0.69–0.70/ 0.86–0.89 mm, elytra 0.88–0.93/ 1.07–1.09 mm; abdomen 1.26–1.30/ 0.97–0.98 mm; length of antenna 1.86–1.93 mm; maximum width of genital complex ( Fig. 6D ) 0.33 mm.

Comparative notes. This species morphologically resembles F. myanmarensis described above, but differs in the smaller body size (3.28–3.43 mm vs. 4.06–4.23 mm), a differently shaped projection of the male metatrochanter, a relatively much shorter male abdomen, lack of a median impression on male tergite 5 (VIII), and lack of a dorsal spine on female tergites 2–4 (V–VII).

Etymology. The species is named after Leonardo Fea, collector of the holotype.

Distribution. Southern Myanmar: Tanintharyi ( Fig. 7 ).

Figures

Fig. 5. Morphology of Feabatrus leonardoi sp. nov., male. A – dorsal habitus; B – head and pronotum; C – mesotrochanter; D – mesotibia; E – metatrochanter; F, G – tergite 5 (VIII), dorsal (F), and lateral (G); H – sternite 6 (VIII); I – sternite 7 (IX); J–L – aedeagus, lateral (J), ventral (K) and dorsal (L). Scale bars: 1.0 mm in A; 0.5 mm in B; 0.2 mm in E–H; 0.1 mm in C, D, I–L.

Fig. 6. Morphology of female Feabatrus species, F. leonardoi sp. nov. (A–D), Feabatrus sp. (E–H). A, E – dorsal habitus; B, F – tergite 5 (VIII); C, G – sternite 6 (VIII); D, H – genital complex. Scale bars: 1.0 mm in A, E; 0.2 mm in B–D, F–H.

Fig. 7. Distribution of Feabatrus species, circle: Feabatrus myanmarensis sp. nov.; triangle: Feabatrus leonardoi sp. nov.; square: Feabatrus sp.