Feabatrus myanmarensis, 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 : 169-171

Feabatrus myanmarensis sp. nov.

( Figs 3 , 4 )

Chinese common name: AEWflüm

Type material. HOLOTYPE: MYANMAR: J, ‘ Carin Asciuii Ghecù (approximate coordinate: 19 ° 41’N, 97°00’E), 1400-1500 m, L. Fea. III-IV. (18)88. / Museo Civico di Genova’ ( MSNG) . PARATYPES: MYANMAR: 4 JJ 5 ♀♀, same data as that of holotype ( MSNG, SNUC).

Diagnosis. Male. Body elongate, length over 4.0 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, with distinct lateral carinae from head base to posterior margin of antennal tubercles; antenna elongate, lacking modification. Pronotum with laterally carinate median and lateral longitudinal sulci, with pair of curved discal carinae, with pair of large discal, antebasal and marginal spines. Elytra sparsely punctate, disc smooth, shiny, discal striae shallow, indistinct. Legs elongate, mesotrochanter with broad ventral spine, mesotibia with small apical spur; metatrochanter with conspicuously long and curved projection. Abdomen elongate and greatly curved ventrally.Aedeagus asymmetrical, median lobe with large basal capsule and foramen, ventral lobe dorso-ventrally abruptly narrowed at apex; dorsal lobe short and flat; endophallus armature composed of extremely slender and curved sclerite; parameres developed into two semi-membranous structures which are sclerotized at bases.

Female. Body length slightly over 4.0 mm. Legs lacking modification. Abdomen shorter than male, tergite 2–4 (V– VII) each in middle with one large spine before posterior margin, tergite 5 (VIII) flat. Genital complex asymmetric, shape as in Figure 4F .

Description. Male. Body ( Figs 3A , 4A ) elongate, length 4.15–4.23 mm; color reddish-brown, tarsi and mouthparts lighter. Dorsal surface of body covered with relatively sparse, long and suberect setae.

Head ( Fig. 3B ) sub-rounded at base, wider than long, length 0.75–0.76 mm, width across eyes 0.85–0.86 mm; vertex with U-shaped sulcus connecting relatively small, but distinct asetose foveae (dorsal tentorial pits), mediobasal carina long, extending from head base anteriorly to middle of frons, lateral carina thick, extending from posterior margin of antennal tubercle toward postocular margin; posterolateral margin weakly angulate; frons anteriorly demarcated from clypeus by oblique carinae merged in middle and extending anteriorly to near 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 70 ommatidia. Antenna elongate, lacking distinct club or modification, length 2.40–2.53 mm; antennomere 1 thick, subcylindrical, 2 shortest, approximately as long as wide, 3–8 each elongate, 8 smaller than 7 and 9, 9–11 slightly broad, with relatively dense setae, 11 largest, slightly longer than 9 and 10 combined (42:38), nearly fusiform.

Pronotum ( Fig. 3B ) wider than long, length 0.78–0.81 mm, width 1.02–1.03 mm, widest in middle; lateral margin with small extra denticles in apical half, 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 short discal carinae connecting large discal and antebasal spines; lateral longitudinal sulcus thick and long; with dense pubescence lateral to sulcus; with pair 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; thin but distinct hypomeral carina extending from base to level of lateral procoxal foveae, with two antebasal hypomeral pits; margin of coxal cavity moderately carinate.

Elytra slightly wider than long, length 1.15–1.17 mm, width 1.23–1.28 mm, disc smooth and shiny, sparsely punctate; each elytron with three moderately large, asetose basal foveae; discal striae shallow, extending posteriorly from outer basal foveae to approximately 2/5 of elytral length; humeri roundly prominent, lacking subhumeral fovea, carinate marginal striae extending from basal 2/3 to posterior margin of elytra.

Mesoventrite short, demarcated from metaventrite by transverse, oblique carinae lateral to mesocoxal cavities; median mesoventral foveae moderately separated, originating from shared transversal opening, large lateral mesoventral foveae forked internally, with short mesoventral process, with complete marginal striae. 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. 3C ) with broad, blunt ventral spine, mesotibia ( Fig. 3D ) with small, short apical spine; metatrochanter ( Fig. 3E ) with conspicuously long ventral projection which is greatly curved at apex, projection densely setose before apex; metatibia slightly curved in middle.

Abdomen conspicuously elongate and curved ventrally, widest at lateral margins of tergite 1 (IV), length 1.80–1.86 mm, width 1.10–1.12 mm. Tergite 1 (IV) approximately 1.2 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 as long as 3 (VI) but shorter than 4 (VII), 2–4 each with one pair of basolateral foveae and thin marginal carinae; tergite 5 (VIII) semicircular ( Figs 3F, G ), elongate, 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 sternite with one pair of small basolateral foveae, sternite 6 (VIII) ( Fig. 3H ) transverse, deeply impressed in middle, posterior margin medially protruding, sternite 7 (IX) ( Fig. 3I ) composed of pair of subtriangular, membranous structures.

Aedeagus ( Figs 3J–L ) 0.62 mm long, asymmetric, stout; median lobe with large basal capsule and foramen, basoventral projection short; ventral stalk narrowed apically, with two small elongate sclerites before apex; dorsal lobe short and flat; endophallus armature extremely elongate, C-shaped in dorsal view; parameres composed of two semi-membranous, basally sclerotized structures.

Female. Similar to male in external morphology. Body ( Figs 4B, C ) and antenna shorter. Each compound eye composed of approximately 70 ommatidia; legs lacking modification; tergites 1–4 (IV–VII) shorter than male, 2–4 each in middle with one large spine before posterior margin, tergite 5 (VIII) flat ( Fig. 4D ), trapezoidal, posterior margin shallowly emarginate and with small nodule in middle; sternite 6 (VIII) transverse ( Fig. 4E ), posterior margin broadly emarginate, with pair of round projections in middle. Measurements (as for male): body length 4.06– 4.12 mm; length/width of head 0.72–0.73/ 0.83–0.85 mm, pronotum 0.78–0.80/0.99–1.00 mm, elytra 1.09/ 1.26–1.28 mm; abdomen 1.65–1.71/ 1.15–1.17 mm; length of antenna 2.17–2.28 mm; maximum width of genital complex ( Fig. 4F ) 0.39 mm.

Comparative notes. This species is morphologically similar to F. leonardoi described below. They can be readily separated by the larger body size (4.06–4.23 mm vs. 3.28–3.43 mm), a much more elongate and greatly curved male abdomen, longer projection of male metatrochanter, male sternite 6 (VIII) with a broad, deep median impression (impression lacking in F. leonardoi ), and presence of long spines on female tergites 2–4 (V–VII).

Etymology. The new species is named after Myanmar, where its type locality is located; adjective.

Distribution. Central Myanmar: southern Shan State ( Fig. 7 ).

Figures

Fig. 3. Morphology of Feabatrus myanmarensis 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, ventral (J), lateral (K) and dorsal (L). Scale bars: 1.0 mm in A; 0.5 mm in B; 0.3 mm in E; 0.2 mm in C, F–H; 0.1 mm in D, I–L.

Fig. 4. Morphology of Feabatrus myanmarensis sp. nov., male (A), female (B–F). A, C – lateral habitus; B – dorsal habitus; D – tergite 5 (VIII); E – sternite 6 (VIII); F – genital complex. Scale bars: 1.0 mm in A, B, C; 0.2 mm in D, E; 0.1 mm in F.

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