Cephennodes (Cephennodes) thakanus, Jałoszyński, 2017

Jałoszyński, Paweł, 2017, Ant-like stone beetles on the roof of the world. Cephenniini of Nepal and Bhutan (Coleoptera, Staphylinidae, Scydmaeninae), Zootaxa 4349 (1), pp. 1-120 : 48-50

Cephennodes (Cephennodes) thakanus sp. n.

( Figs 99 , 109 , 132–135 , 146 )

Type material. Holotype: NEPAL (Mustang District): ♂, " NEPAL Mustang / Distr. 2km N Ka- / lopani 2550m 1.X. / 83 Smetana&Löbl [white, printed] ( MHNG). Paratype: 1 ♂, " NEPAL Manang / Distr. For. W Bagar- / chhap 2200m 21.IX. / 83 Smetana & Löbl [white, printed] ( MHNG).

Diagnosis. BL 1.33–1.40 mm; body moderately stout, with elytra weakly narrowing behind the broadest site; distal portion of metatibia strongly thickened, with oval subapical porous field much longer than broad and with one remarkably long bristle within short setal fringe of apical margin; abdomen in ventral view with posterior margin of sternite II slightly concave at middle, sternite III bearing broadly rounded median lobe; apical portion of median lobe of aedeagus nearly subrectangular with rounded corners, its longitudinal axis forming about 30°-angle with long axis of aedeagus; apical projection with strongly concave distal margin and small, subtriangular, welldefined apical lobe.

Description. Body of male ( Fig. 99 ) light brown, with shallow constriction between pronotum and elytra, strongly convex, covered with yellowish setae; BL 1.33–1.38 mm.

Head subtrapezoidal, HL 0.20 mm, HW 0.34–0.35 mm; vertex and frons confluent, evenly and weakly convex; supraantennal tubercles small and weakly elevated; eyes large, strongly convex, coarsely faceted. Punctures on frons and vertex small but distinct, relatively sharply marked, densely and unevenly distributed, sparser at middle and denser on sides, those in middle of frons between eyes separated by spaces 1–2 × as wide as diameters of punctures; setae short, moderately dense, suberect to erect. Antennae relatively short and moderately slender, AnL 0.73–0.75 mm, pentamerous club indistinctly delimited; antennomere I 1.5 × as long as broad; II slightly narrower and indistinctly shorter than I, about 1.6 × as long as broad; III–VI similar in shape, each slightly narrower and much shorter than II, about 1.1–1.2 × as long as broad, VII slightly broader and longer than VI, about 1.1 × as long as broad; VIII slightly broader but distinctly shorter than VII, slightly transverse; IX and X each distinctly larger than preceding one, each slightly transverse, XI much broader than X, about as long as IX–X together, about twice as long as broad.

Pronotum in dorsal view nearly semicircular, broadest slightly in front of middle but very indistinctly narrowing posteriorly, PL 0.40–0.43 mm, PW 0.58–0.63 mm; anterior margin broadly and weakly rounded; lateral margins not serrate, strongly rounded in anterior half, nearly straight in posterior half; posterior corners nearly right-angled; posterior margin shallowly bisinuate; lateral carinae narrow and fused with lateral margins; antebasal pits small and very shallow, the deepest site of each pit located much closer to posterior than to lateral margin of pronotum. Punctures on disc very small and shallow, inconspicuous; setae dense, short, suberect.

Elytra short, oval, broadest between middle and anterior third, EL 0.73–0.75 mm, EW 0.65–0.68 mm, EI 1.11– 1.12. Humeral calli weakly elevated; subhumeral lines distinct, equal to about 0.4 EL, each developed as a groove between more convex humeral region and less convex adsutural area; basal pit on each elytron large and connected to short, slightly arcuate impression extending posteromesally; apices of elytra separately rounded. Punctures on elytra more distinct than those on pronotum but superficial, diffuse and inconspicuous; setae about as dense and short as those on pronotum but less erect.

Hind wings not studied.

Metaventrite with large and sharply delimited postmesocoxal impressions, median part covered with very fine punctures.

Hind legs with strongly modified tibiae ( Fig. 109 ); in dorsal view lateral (external) tibial margin weakly recurved and spatulate portion of tibia gradually narrowed distally, with rounded, not angulate external margin; dorsodistal porous field much longer than broad; distal fringe of setae with one outstanding long bristle.

Abdomen ( Figs 132–133 ) with posterior margin of sternite II slightly emarginate at middle; sternite III bearing broadly rounded, short median lobe.

Aedeagus ( Figs 134–135 ) moderately slender; AeL 0.20 mm, apical portion of median lobe slightly asymmetrical, subrectangular with rounded corners, its longitudinal axis forming about 30°-angle with the long axis of aedeagus; apical projection with deeply concave distal margin, its apex forming well-defined, small elongate lobe; parameres long and slender, not exceeding apex of median lobe, each bearing one apical seta.

Female. Unknown.

Distribution ( Fig. 146 ). Central Nepal.

Etymology. Locotypical, after Thak, the local name of the southern part of Mustang District.

Remarks. Adults of this species are much smaller than those of C. dolakhanus , C. martensi , C. paramartensi , C. monolaminatus and C. parbatensis ; they are comparable in length with C. manangensis and C. annapurnaensis . Cephennodes thakanus differs from C. manangensis in the aedeagus, which has the apical portion of the median lobe clearly less curved outwards the long axis of aedeagus and subrectangular (strongly curved outwards and rounded subtriangular in C. manangensis ), and the apical portion of the apical projection has a small, well-defined lobe in C. thakanus (much larger, less distinctly defined lobe in C. manangensis ). Cephennodes manangensis is also slightly smaller, BL 1.25–1.30 mm vs. 1.33–1.38 mm in C. thakanus . Cephennodes thakanus clearly differs from C. annapurnaensis in the shape of the apical portion of apical projection (with an elongate, well-defined lobe in C. thakanus vs. subtriangular in C. annapurnaensis ), and the apex of median lobe (subrectangular and narrow in C. thakanus vs. rounded and distinctly broader in C. annapurnaensis ).

Figures

FIGURES 94 – 101. Dorsal habitus of Cephennodes (s. str.) dolakhanus s sp. n. (94), C. (s. str.) manangensis sp. n. (95), C. (s. str.) martensi sp. n. (96), C. (s. str.) paramartensi sp. n. (97), C. (s. str.) monolaminatus sp. n. (98), C. (s. str.) thakanus sp. n. (99), C. (s. str.) annapurnaensis sp. n. (100), and C. (s. str.) parbatensis sp. n. (101).

FIGURES 102 – 111. Right metatibia of male in dorsal view. Cephennodes (s. str.) dolakhanus s sp. n. (102, 104), C. (s. str.) manangensis sp. n. (103, 105), C. (s. str.) martensi sp. n. (106), C. (s. str.) paramartensi sp. n. (107), C. (s. str.) monolaminatus sp. n. (108), C. (s. str.) thakanus sp. n. (109), C. (s. str.) annapurnaensis sp. n. (110), and C. (s. str.) parbatensis sp. n. (111). 104 – 111 not to the same scale.

FIGURES 128 – 143. Abdomen of male in right lateral (128, 132, 136, 140) and ventral (129, 133, 137, 141) views and aedeagus in ventral (130, 134, 138, 142) and lateral (131, 135, 139, 143) views. Cephennodes C. (s. str.) monolaminatus sp. n. (128 – 131), C. (s. str.) thakanus sp. n. (132 – 135), C. (s. str.) annapurnaensis sp. n. (136 – 139), and C. (s. str.) parbatensis sp. n. (140 – 143). Abbreviations: aml, apex of median lobe; ap, apical projection.

FIGURES 146 – 147. Distribution of Cephennodes (s. str.) monolaminatus sp. n. (146, circle), C. (s. str.) thakanus sp. n. (144, triangle), C. (s. str.) annapurnaensis sp. n. (147, circle), C. (s. str.) parbatensis sp. n. (147, triangle).